1) High-resolution gravity data from NASA's GRAIL mission shows distinctive "bulls-eye" patterns of gravity anomalies over lunar impact basins, with a central positive anomaly surrounded by a negative collar and outer positive annulus.
2) The document uses hydrocode modeling and finite element modeling to show that these mascon gravity patterns naturally result from the excavation and collapse of an impact crater, followed by post-impact isostatic adjustment and cooling/contraction of the melt pool.
3) The modeling is able to replicate the observed gravity anomalies of the Freundlich-Sharanov and Humorum basins, supporting the theory that mascons form through this impact and relaxation process rather than
The document summarizes a new model for the formation of mascons, or regions of increased mass concentration, on the Moon. Previous models could not fully explain how the initial mass deficit created by asteroid impacts turned into a mass excess. The new model proposed by Melosh et al. suggests that slow mantle flow driven by the low-density crustal annulus and mantle below the impact basin causes uplift over time and results in a frozen-in structure with a high-density interior surrounded by a lower-density ring, creating the mascon. This model provides constraints on the thermal conditions required for mascons to form and suggests mascons could be used to study the ancient heat flux of the Moon, Mars, and Mercury.
The document describes simulations of a collision between the Moon and a companion moon approximately 1/3 the diameter of the Moon. The simulations found that at the modeled subsonic impact velocity, the companion moon did not form an impact crater but was instead accreted onto the Moon's surface. This added material contributed a hemispheric layer comparable to the extent and thickness of the lunar farside highlands. The collision also displaced the Moon's magma ocean to the opposite hemisphere, potentially explaining the observed concentration of KREEP materials. The findings suggest this late accretion event could explain the geological dichotomy between the lunar near and farside regions.
1. The document discusses concepts in geophysics including isostasy, density, susceptibility, and resistivity of rocks. Isostasy refers to equilibrium between the earth's lithosphere and asthenosphere. Density is a measure of how tightly packed molecules are in a material. Susceptibility measures a material's magnetization in response to an external magnetic field. Resistivity quantifies a material's opposition to electric current flow.
2. Igneous rocks generally have higher density, susceptibility, and resistivity compared to metamorphic and sedimentary rocks. This is because igneous rocks contain more mafic minerals and have undergone less alteration from their original state than other rock types. Factors like pore space,
This document discusses the concept of isostasy, which refers to the equilibrium between the continental and oceanic crust due to gravitational forces. It was first defined in 1889 by American geologist Clarence Dutton. The main points are that the continental crust must be composed of lighter materials than the ocean floor to remain in equilibrium. Also, wherever the continental crust is thinner under the oceans, it extends below the ocean floor to maintain equilibrium. Early evidence for isostasy came from Pierre Bouguer's 1735 expedition to the Andes mountains, where he observed smaller than expected gravitational attraction that indicated compensation of the mountains' mass.
Hawaii's Most Active Volcano: Here's The Latest On Kilauea's Eruption
The Kilauea volcano is located in the southeastern part of the Big Island of Hawaii.
Believe it or not, Kilauea has been erupting continuously since 1983, with only occasional pauses of quiet activity. This particular "episode" of the eruption began in the late afternoon of May 3, in a part of Leilani Estates, a subdivision near the town of Pahoa.
Officials said there is no way to predict how long the eruption will continue or what shape it will take. This eruption could be finished or could go on for a long time.
Kilauea is one of the most active and well-monitored volcanoes in the world. It's been erupting on and off for hundreds of thousands of years.
All of Hawaii is a tourist destination, but this particular eruption wasn't in an area where most tourists go. The homes at risk are in a subdivision near the town of Pahoa.
Source: USA TODAY. By Doyle Rice. May 4, 2018, accessed May 5, 2018
<https://www.usatoday.com/story/news/nation/2018/05/04/hawaii-volcano-eruption-kilauea-big-island/580466002/>
________________________
Kilauea Volcano Erupts, Spewing Lava and Gases Near Homes in Hawaii
Governor David Ige has issued an emergency proclamation and has called up the National Guard to help emergency workers with evacuation efforts.
Source: THE NEW YORK TIMES. By Meghan Miner Murray, Sabrina Tavernise and Maya Salam. May 4, 2018, accessed May 5, 2018
<https://www.nytimes.com/2018/05/04/us/kilauea-volcano-eruption-hawaii.html>
The document discusses several active geological processes observed on Mars including slope streaks, gully formation, recurring slope lineae (RSL), dust avalanches, and impacts. Slope streaks are believed to form from downslope movement of dry sand or dust in an almost fluid-like manner, exposing darker material underneath. Gullies are thought to form from seasonal frost or from the sublimation of dry ice blocks, which can slide down dune slopes. RSL are dark flows on steep rocky slopes that are correlated with seasonal frost. Dust avalanches and small asteroid impacts continue to shape Mars' surface and may trigger slope streaks. HiRISE images provide evidence that Mars remains an active planet, with subtle changes
Isostasy refers to the equilibrium between blocks of Earth's crust and the underlying mantle. Lighter crustal blocks "float" higher, while heavier blocks sink deeper into the mantle. There are three models of isostasy: the Airy-Heiskanen model where crustal thickness changes with topography; the Pratt-Hayford model where lateral density changes accommodate topography; and the flexural isostasy model where the lithosphere bends under local loads. Deposition and erosion affect isostatic equilibrium as crust rises when loaded and sinks when unloaded, like an iceberg. Plate tectonics and ice sheets also impact isostasy through crustal thickening during collisions and post-gl
The document summarizes key aspects of seismology and plate tectonics. It describes how seismology studies earthquakes and seismic wave propagation to understand Earth's internal structure. It then outlines Earth's major layers - crust, mantle, and core. It introduces the theories of continental drift and plate tectonics to explain the movement of tectonic plates across Earth's surface, driven by convection currents in the mantle. It categorizes the three main types of plate boundaries - divergent boundaries where plates spread apart, convergent boundaries where they collide subduct or collide, and provides examples of each.
The document summarizes a new model for the formation of mascons, or regions of increased mass concentration, on the Moon. Previous models could not fully explain how the initial mass deficit created by asteroid impacts turned into a mass excess. The new model proposed by Melosh et al. suggests that slow mantle flow driven by the low-density crustal annulus and mantle below the impact basin causes uplift over time and results in a frozen-in structure with a high-density interior surrounded by a lower-density ring, creating the mascon. This model provides constraints on the thermal conditions required for mascons to form and suggests mascons could be used to study the ancient heat flux of the Moon, Mars, and Mercury.
The document describes simulations of a collision between the Moon and a companion moon approximately 1/3 the diameter of the Moon. The simulations found that at the modeled subsonic impact velocity, the companion moon did not form an impact crater but was instead accreted onto the Moon's surface. This added material contributed a hemispheric layer comparable to the extent and thickness of the lunar farside highlands. The collision also displaced the Moon's magma ocean to the opposite hemisphere, potentially explaining the observed concentration of KREEP materials. The findings suggest this late accretion event could explain the geological dichotomy between the lunar near and farside regions.
1. The document discusses concepts in geophysics including isostasy, density, susceptibility, and resistivity of rocks. Isostasy refers to equilibrium between the earth's lithosphere and asthenosphere. Density is a measure of how tightly packed molecules are in a material. Susceptibility measures a material's magnetization in response to an external magnetic field. Resistivity quantifies a material's opposition to electric current flow.
2. Igneous rocks generally have higher density, susceptibility, and resistivity compared to metamorphic and sedimentary rocks. This is because igneous rocks contain more mafic minerals and have undergone less alteration from their original state than other rock types. Factors like pore space,
This document discusses the concept of isostasy, which refers to the equilibrium between the continental and oceanic crust due to gravitational forces. It was first defined in 1889 by American geologist Clarence Dutton. The main points are that the continental crust must be composed of lighter materials than the ocean floor to remain in equilibrium. Also, wherever the continental crust is thinner under the oceans, it extends below the ocean floor to maintain equilibrium. Early evidence for isostasy came from Pierre Bouguer's 1735 expedition to the Andes mountains, where he observed smaller than expected gravitational attraction that indicated compensation of the mountains' mass.
Hawaii's Most Active Volcano: Here's The Latest On Kilauea's Eruption
The Kilauea volcano is located in the southeastern part of the Big Island of Hawaii.
Believe it or not, Kilauea has been erupting continuously since 1983, with only occasional pauses of quiet activity. This particular "episode" of the eruption began in the late afternoon of May 3, in a part of Leilani Estates, a subdivision near the town of Pahoa.
Officials said there is no way to predict how long the eruption will continue or what shape it will take. This eruption could be finished or could go on for a long time.
Kilauea is one of the most active and well-monitored volcanoes in the world. It's been erupting on and off for hundreds of thousands of years.
All of Hawaii is a tourist destination, but this particular eruption wasn't in an area where most tourists go. The homes at risk are in a subdivision near the town of Pahoa.
Source: USA TODAY. By Doyle Rice. May 4, 2018, accessed May 5, 2018
<https://www.usatoday.com/story/news/nation/2018/05/04/hawaii-volcano-eruption-kilauea-big-island/580466002/>
________________________
Kilauea Volcano Erupts, Spewing Lava and Gases Near Homes in Hawaii
Governor David Ige has issued an emergency proclamation and has called up the National Guard to help emergency workers with evacuation efforts.
Source: THE NEW YORK TIMES. By Meghan Miner Murray, Sabrina Tavernise and Maya Salam. May 4, 2018, accessed May 5, 2018
<https://www.nytimes.com/2018/05/04/us/kilauea-volcano-eruption-hawaii.html>
The document discusses several active geological processes observed on Mars including slope streaks, gully formation, recurring slope lineae (RSL), dust avalanches, and impacts. Slope streaks are believed to form from downslope movement of dry sand or dust in an almost fluid-like manner, exposing darker material underneath. Gullies are thought to form from seasonal frost or from the sublimation of dry ice blocks, which can slide down dune slopes. RSL are dark flows on steep rocky slopes that are correlated with seasonal frost. Dust avalanches and small asteroid impacts continue to shape Mars' surface and may trigger slope streaks. HiRISE images provide evidence that Mars remains an active planet, with subtle changes
Isostasy refers to the equilibrium between blocks of Earth's crust and the underlying mantle. Lighter crustal blocks "float" higher, while heavier blocks sink deeper into the mantle. There are three models of isostasy: the Airy-Heiskanen model where crustal thickness changes with topography; the Pratt-Hayford model where lateral density changes accommodate topography; and the flexural isostasy model where the lithosphere bends under local loads. Deposition and erosion affect isostatic equilibrium as crust rises when loaded and sinks when unloaded, like an iceberg. Plate tectonics and ice sheets also impact isostasy through crustal thickening during collisions and post-gl
The document summarizes key aspects of seismology and plate tectonics. It describes how seismology studies earthquakes and seismic wave propagation to understand Earth's internal structure. It then outlines Earth's major layers - crust, mantle, and core. It introduces the theories of continental drift and plate tectonics to explain the movement of tectonic plates across Earth's surface, driven by convection currents in the mantle. It categorizes the three main types of plate boundaries - divergent boundaries where plates spread apart, convergent boundaries where they collide subduct or collide, and provides examples of each.
The document discusses several topics related to oceanic lithosphere and plate tectonics. It describes how subducting oceanic plates can be delineated by inclined zones of seismicity, known as Wadati-Benioff zones, that studies show are colder than the surrounding mantle. It also explains how oceanic crust and lithosphere thicken away from mid-ocean ridges due to isostatic compensation, and how oceanic plates move away from ridges and eventually descend at subduction zones as they reheat. Heat drives plate tectonics as the cooling oceanic lithosphere forms strong plates that move and interact at plate boundaries.
The document discusses the geological concept of isostasy. Isostasy refers to the principle of buoyancy where land masses float on the denser underlying mantle material. It explains that mountains create indentations in the earth's crust similar to placing a heavy object on a rubber ball. It also describes early theories on isostasy from Clarence Dutton, who coined the term, and Sir George Airy, who proposed that land masses float with varying thickness but uniform density. The concept was later refined by A. Pratt to propose uniform depth but varying density between land masses.
This document summarizes a geophysical study conducted near Mammoth Lakes, CA to interpret subsurface geology. Seismic refraction, gravity, magnetometer, and electrical resistivity surveys were performed. Seismic data indicated three layers - unconsolidated alluvium, consolidated alluvium, and brecciated rhyolite. Gravity data matched this model and suggested a fault filled with low-density material. Magnetometer data showed a low magnetic susceptibility fault zone and intrusive igneous dikes. Together, the techniques provided evidence for faults channeling hydrothermal fluids, which could be a geothermal energy resource.
The document provides information about planet Earth. It discusses that Earth is the third planet from the sun, the largest of the inner planets, and is known by names like the Blue Planet. It formed 4.6 billion years ago from a solar nebula and molten material that collided to form the planet. Early Earth had extreme conditions that changed over time as the atmosphere stabilized and continents formed, allowing life to emerge in the oceans. The document details Earth's structure, composition, atmosphere, seasons, and key facts about its orbit, rotation, and relationship to the moon.
The document discusses the concept of geosynclines, which refers to thick piles of sediments deposited in deep marine basins that were later compressed, deformed, and uplifted to form mountain ranges. Geosynclines developed in three phases - first sediments accumulated in a subsiding trough (geosynclinal phase), then the deeply buried sediments folded under heat and pressure (tectonic phase), and finally horizontal compression forces uplifted the folded rocks to form mountains tens of thousands of meters high (orogenic phase). Geosynclines are classified as orthgeosynclines like eugeosynclines that formed far from continents with volcanic rocks, or parageosynclines like miogeosyn
This document provides an overview of impact cratering mechanics and morphology. It explains that when objects impact planetary surfaces, they release enormous amounts of kinetic energy that excavates craters. There are two main types of craters - simple bowl-shaped craters and more complex craters with interior structures like terraces and central peaks. The size and morphology of craters depends on factors like the impacting object's energy, the planet's gravity, and the properties of the surface materials. Heavily cratered surfaces on bodies like the Moon record an earlier intense bombardment period in the solar system's history.
Concept of isostatic adjustment and isostatic models parag sonwane
This document discusses the geological concept of isostasy, which refers to the equilibrium between Earth's crust and mantle such that the crust "floats" at an elevation that depends on its thickness and density. It presents several theories of isostasy, including Airy's theory which proposes that thicker crustal areas sink deeper into the mantle, and Pratt's theory which suggests areas of lower crustal density project higher. The document also discusses isostatic effects from processes like deposition, erosion, and past ice sheets, as well as concepts like phase changes and Heiskanen's modification of Airy's theory.
- The document discusses various theories of isostasy proposed by scientists like Airy, Pratt, Hayford, Bowie, and Joly.
- Airy proposed that mountains are floating in denser magma below, similar to how boats float in water. Pratt proposed mountains have varying densities that compensate for their mass at a level of compensation.
- Hayford and Bowie proposed columns of crust reaching a level of compensation at 100km depth, with densities varying above but uniform below this level. Joly rejected this idea due to high temperatures at that depth.
Earthquakes are caused by the release of elastic strain energy stored in rocks along faults. The Earth's surface consists of tectonic plates that are constantly moving due to convection currents in the mantle. Where the plates meet, they can collide, move apart, or move past each other, building up stress. If the stress becomes too great, the rocks suddenly slip along a fault, releasing energy in waves called seismic waves. There are two main types of earthquakes - interplate quakes at plate boundaries and intraplate quakes within plates. Fault slip during quakes can be vertical, horizontal, or lateral.
1) Different scientists proposed theories to explain discrepancies found during geodetic surveys near mountain ranges like the Himalayas, where gravitational measurements did not match the expected values given the mountains' enormous masses.
2) This led to the concept of isostasy, first proposed by Dutton in 1859, which theorized that the Earth's crust exists in equilibrium, with underground compensation balancing surface topography.
3) Early theorists like Airy and Pratt developed models to explain how lighter rock could float within denser rock to compensate for surface features like mountains, relating their ideas to principles of buoyancy seen with icebergs floating in water.
Venusian Habitable Climate Scenarios: Modeling Venus Through Time and Applica...Sérgio Sacani
One popular view of Venus' climate history describes a world that has spent much of its life
with surface liquid water, plate tectonics, and a stable temperate climate. Part of the basis for this
optimistic scenario is the high deuterium to hydrogen ratio from the Pioneer Venus mission that was
interpreted to imply Venus had a shallow ocean's worth of water throughout much of its history. Another
view is that Venus had a long-lived (∼100 million years) primordial magma ocean with a CO2 and steam
atmosphere. Venus' long-lived steam atmosphere would sufficient time to dissociate most of the water
vapor, allow significant hydrogen escape, and oxidize the magma ocean. A third scenario is that Venus had
surface water and habitable conditions early in its history for a short period of time (<1 Gyr), but that a
moist/runaway greenhouse took effect because of a gradually warming Sun, leaving the planet desiccated
ever since. Using a general circulation model, we demonstrate the viability of the first scenario using the
few observational constraints available.We further speculate that large igneous provinces and the global
resurfacing hundreds of millions of years ago played key roles in ending the clement period in its history
and presenting the Venus we see today. The results have implications for what astronomers term “the
habitable zone,” and if Venus-like exoplanets exist with clement conditions akin to modern Earth, we
propose to place them in what we term the “optimistic Venus zone.”
1) Earthquakes are caused by the sudden release of elastic strain energy that builds up in tectonic plates due to their slow relative movements.
2) The Earth's interior is differentiated into layers with the outer core, mantle, and crust composed of lighter rocks overlying denser materials towards the center.
3) Convection currents in the mantle cause the crust and some mantle to break into tectonic plates that move relative to one another, building up elastic stress at plate boundaries.
This document discusses several theories of mountain building:
1. The geosyncline orogen theory of Kober proposes that mountains form in mobile zones called geosynclines that are surrounded by rigid land masses and subjected to contraction forces from Earth's cooling.
2. Jeffreys' thermal contraction theory attributes mountain-building forces to cooling of the Earth and slowing of its rotation. This explains the perpendicular orientation of mountains to continental margins.
3. Joly's radioactive theory proposes that heat from radioactive elements in the crust causes expansion and contraction cycles leading to deposition of sediments in geosynclines that are later compressed into mountains.
4. Daly proposed that gravity drives downhill sliding of continental masses. Holmes suggested
- The document discusses several concepts of isostasy proposed by scientists like Airy, Pratt, Hayford, Bowie, and Joly.
- According to Airy, mountains are compensated by being less dense than the material below and "float" in the denser lower crust and mantle, similar to how a boat floats. Pratt proposed that density varies inversely with elevation above a compensation level, with uniform density below.
- Hayford and Bowie suggested columns of crust above a compensation plane have varying densities balancing their heights, with uniform density below this plane around 100km depth. However, Joly disagreed with this proposed depth of compensation.
The document discusses different types of mountain formation processes at convergent and divergent plate boundaries. At convergent boundaries, colliding plates provide compression that folds and metamorphoses sediments, forming mountains. Where oceans converge, volcanic mountains are mainly produced, while ocean-continent convergence can result in both volcanic and folded mountains. Continental collisions result in folded mountains, and mountains along divergent mid-ocean ridges are fault-block type. Following mountain building, thickened crust undergoes regional uplift due to isostatic adjustment for long periods.
North america may have once been attached to australiaJulianne Cox
North America may have once been attached to Australia based on evidence from ancient sedimentary rocks in Arizona and New Mexico. Zircon crystals found in these rocks date to 1.6-1.5 billion years old, an age range not present in North America but matching rocks in Australia and Antarctica. This suggests North America was linked to Australia and Antarctica as part of a supercontinent called Columbia until its breakup 1.5 billion years ago. Continued study of ancient sedimentary basins will help test reconstructions of global supercontinents like Columbia and Rodinia.
This Presentaion will give us knowledge about our planet Earth..with regards to its Size, Shape, Inner Structure, Atmosphere Etc..
Hope you like it.. Enjoy Watching
The document summarizes research on the origin of lunar concentric craters. The researchers analyzed data from Clementine, SELENE, and LRO to study 58 known concentric craters. They identified three morphological types and found concentric craters have shallower depths and smaller rim heights than fresh simple craters, suggesting impact degradation or uplift. Distribution near mare/highland boundaries and similarities to floor-fractured craters supports igneous intrusion as the most probable formation mechanism, rather than exogenic processes like simultaneous impacts or impact into layered targets.
Geology 1: Notes on Earth's geologic forces that shape the crust with video ...Robin Seamon
The document provides an overview of geology and the structure of the Earth. It discusses the layers of the Earth including the core, mantle and crust. It describes different types of volcanoes such as shield volcanoes, cinder cone volcanoes, and composite volcanoes. It also covers plate tectonics, earthquakes, weathering and erosion.
1) Global climate models that include sophisticated cloud schemes show that tidally locked planets can develop thick water clouds near the substellar point due to strong convection. These clouds greatly increase the planetary albedo and stabilize temperatures, allowing habitability at twice the stellar flux previously thought possible.
2) The cloud feedback is stabilizing, as higher stellar flux produces stronger convection and higher albedos. Substellar clouds can block outgoing radiation, reducing the day-night temperature contrast.
3) Non-tidally locked planets do not experience this stabilizing cloud feedback, as clouds only form over parts of the tropics and mid-latitudes. Their albedo decreases with increasing stellar flux, producing a destabil
Temporal and Spatial Distribution of Wind Vector Fields and Arctic Sea-Ice Le...priscillaahn
Ice packs are constantly subject to ocean current and wind forces, causing cracks to form in rigid winter sea ice. Under enough stress, these cracks can propagate into large-scale fractures, or “leads”. Understanding how sea-ice leads form can provide insight into the net thinning of the Arctic sea-ice pack.
Leads in the Arctic sea-ice pack occur in distinct geometric patterns and sequences similar to those in rock. This suggests that the Mohr Coulomb principle of rock brittle deformation can possibly explain the spatial and temporal distribution of brittle failure in sea ice.
Gigantic submarine landslides are among the most energetic events on the Earth surface. During the
Late Pleistocene the Mediterranean Sea was the scenario of a 9 number of such events, some of whose
geological fi ngerprints are the 500 km3 mass transport deposit SL2 at the Nile delta fan (dated at ca. 110
ka BP) and the Herodotus Basing Megaturbidite (HBM, a 400 km3 deposit dated at ca. 27.1 ka BP). This
paper presents an exploratory study on the tsunamigenic potential of these slides by using a numerical
model based on the 2D depth-averaged non-linear barotropic shallow water equations.
The document discusses several topics related to oceanic lithosphere and plate tectonics. It describes how subducting oceanic plates can be delineated by inclined zones of seismicity, known as Wadati-Benioff zones, that studies show are colder than the surrounding mantle. It also explains how oceanic crust and lithosphere thicken away from mid-ocean ridges due to isostatic compensation, and how oceanic plates move away from ridges and eventually descend at subduction zones as they reheat. Heat drives plate tectonics as the cooling oceanic lithosphere forms strong plates that move and interact at plate boundaries.
The document discusses the geological concept of isostasy. Isostasy refers to the principle of buoyancy where land masses float on the denser underlying mantle material. It explains that mountains create indentations in the earth's crust similar to placing a heavy object on a rubber ball. It also describes early theories on isostasy from Clarence Dutton, who coined the term, and Sir George Airy, who proposed that land masses float with varying thickness but uniform density. The concept was later refined by A. Pratt to propose uniform depth but varying density between land masses.
This document summarizes a geophysical study conducted near Mammoth Lakes, CA to interpret subsurface geology. Seismic refraction, gravity, magnetometer, and electrical resistivity surveys were performed. Seismic data indicated three layers - unconsolidated alluvium, consolidated alluvium, and brecciated rhyolite. Gravity data matched this model and suggested a fault filled with low-density material. Magnetometer data showed a low magnetic susceptibility fault zone and intrusive igneous dikes. Together, the techniques provided evidence for faults channeling hydrothermal fluids, which could be a geothermal energy resource.
The document provides information about planet Earth. It discusses that Earth is the third planet from the sun, the largest of the inner planets, and is known by names like the Blue Planet. It formed 4.6 billion years ago from a solar nebula and molten material that collided to form the planet. Early Earth had extreme conditions that changed over time as the atmosphere stabilized and continents formed, allowing life to emerge in the oceans. The document details Earth's structure, composition, atmosphere, seasons, and key facts about its orbit, rotation, and relationship to the moon.
The document discusses the concept of geosynclines, which refers to thick piles of sediments deposited in deep marine basins that were later compressed, deformed, and uplifted to form mountain ranges. Geosynclines developed in three phases - first sediments accumulated in a subsiding trough (geosynclinal phase), then the deeply buried sediments folded under heat and pressure (tectonic phase), and finally horizontal compression forces uplifted the folded rocks to form mountains tens of thousands of meters high (orogenic phase). Geosynclines are classified as orthgeosynclines like eugeosynclines that formed far from continents with volcanic rocks, or parageosynclines like miogeosyn
This document provides an overview of impact cratering mechanics and morphology. It explains that when objects impact planetary surfaces, they release enormous amounts of kinetic energy that excavates craters. There are two main types of craters - simple bowl-shaped craters and more complex craters with interior structures like terraces and central peaks. The size and morphology of craters depends on factors like the impacting object's energy, the planet's gravity, and the properties of the surface materials. Heavily cratered surfaces on bodies like the Moon record an earlier intense bombardment period in the solar system's history.
Concept of isostatic adjustment and isostatic models parag sonwane
This document discusses the geological concept of isostasy, which refers to the equilibrium between Earth's crust and mantle such that the crust "floats" at an elevation that depends on its thickness and density. It presents several theories of isostasy, including Airy's theory which proposes that thicker crustal areas sink deeper into the mantle, and Pratt's theory which suggests areas of lower crustal density project higher. The document also discusses isostatic effects from processes like deposition, erosion, and past ice sheets, as well as concepts like phase changes and Heiskanen's modification of Airy's theory.
- The document discusses various theories of isostasy proposed by scientists like Airy, Pratt, Hayford, Bowie, and Joly.
- Airy proposed that mountains are floating in denser magma below, similar to how boats float in water. Pratt proposed mountains have varying densities that compensate for their mass at a level of compensation.
- Hayford and Bowie proposed columns of crust reaching a level of compensation at 100km depth, with densities varying above but uniform below this level. Joly rejected this idea due to high temperatures at that depth.
Earthquakes are caused by the release of elastic strain energy stored in rocks along faults. The Earth's surface consists of tectonic plates that are constantly moving due to convection currents in the mantle. Where the plates meet, they can collide, move apart, or move past each other, building up stress. If the stress becomes too great, the rocks suddenly slip along a fault, releasing energy in waves called seismic waves. There are two main types of earthquakes - interplate quakes at plate boundaries and intraplate quakes within plates. Fault slip during quakes can be vertical, horizontal, or lateral.
1) Different scientists proposed theories to explain discrepancies found during geodetic surveys near mountain ranges like the Himalayas, where gravitational measurements did not match the expected values given the mountains' enormous masses.
2) This led to the concept of isostasy, first proposed by Dutton in 1859, which theorized that the Earth's crust exists in equilibrium, with underground compensation balancing surface topography.
3) Early theorists like Airy and Pratt developed models to explain how lighter rock could float within denser rock to compensate for surface features like mountains, relating their ideas to principles of buoyancy seen with icebergs floating in water.
Venusian Habitable Climate Scenarios: Modeling Venus Through Time and Applica...Sérgio Sacani
One popular view of Venus' climate history describes a world that has spent much of its life
with surface liquid water, plate tectonics, and a stable temperate climate. Part of the basis for this
optimistic scenario is the high deuterium to hydrogen ratio from the Pioneer Venus mission that was
interpreted to imply Venus had a shallow ocean's worth of water throughout much of its history. Another
view is that Venus had a long-lived (∼100 million years) primordial magma ocean with a CO2 and steam
atmosphere. Venus' long-lived steam atmosphere would sufficient time to dissociate most of the water
vapor, allow significant hydrogen escape, and oxidize the magma ocean. A third scenario is that Venus had
surface water and habitable conditions early in its history for a short period of time (<1 Gyr), but that a
moist/runaway greenhouse took effect because of a gradually warming Sun, leaving the planet desiccated
ever since. Using a general circulation model, we demonstrate the viability of the first scenario using the
few observational constraints available.We further speculate that large igneous provinces and the global
resurfacing hundreds of millions of years ago played key roles in ending the clement period in its history
and presenting the Venus we see today. The results have implications for what astronomers term “the
habitable zone,” and if Venus-like exoplanets exist with clement conditions akin to modern Earth, we
propose to place them in what we term the “optimistic Venus zone.”
1) Earthquakes are caused by the sudden release of elastic strain energy that builds up in tectonic plates due to their slow relative movements.
2) The Earth's interior is differentiated into layers with the outer core, mantle, and crust composed of lighter rocks overlying denser materials towards the center.
3) Convection currents in the mantle cause the crust and some mantle to break into tectonic plates that move relative to one another, building up elastic stress at plate boundaries.
This document discusses several theories of mountain building:
1. The geosyncline orogen theory of Kober proposes that mountains form in mobile zones called geosynclines that are surrounded by rigid land masses and subjected to contraction forces from Earth's cooling.
2. Jeffreys' thermal contraction theory attributes mountain-building forces to cooling of the Earth and slowing of its rotation. This explains the perpendicular orientation of mountains to continental margins.
3. Joly's radioactive theory proposes that heat from radioactive elements in the crust causes expansion and contraction cycles leading to deposition of sediments in geosynclines that are later compressed into mountains.
4. Daly proposed that gravity drives downhill sliding of continental masses. Holmes suggested
- The document discusses several concepts of isostasy proposed by scientists like Airy, Pratt, Hayford, Bowie, and Joly.
- According to Airy, mountains are compensated by being less dense than the material below and "float" in the denser lower crust and mantle, similar to how a boat floats. Pratt proposed that density varies inversely with elevation above a compensation level, with uniform density below.
- Hayford and Bowie suggested columns of crust above a compensation plane have varying densities balancing their heights, with uniform density below this plane around 100km depth. However, Joly disagreed with this proposed depth of compensation.
The document discusses different types of mountain formation processes at convergent and divergent plate boundaries. At convergent boundaries, colliding plates provide compression that folds and metamorphoses sediments, forming mountains. Where oceans converge, volcanic mountains are mainly produced, while ocean-continent convergence can result in both volcanic and folded mountains. Continental collisions result in folded mountains, and mountains along divergent mid-ocean ridges are fault-block type. Following mountain building, thickened crust undergoes regional uplift due to isostatic adjustment for long periods.
North america may have once been attached to australiaJulianne Cox
North America may have once been attached to Australia based on evidence from ancient sedimentary rocks in Arizona and New Mexico. Zircon crystals found in these rocks date to 1.6-1.5 billion years old, an age range not present in North America but matching rocks in Australia and Antarctica. This suggests North America was linked to Australia and Antarctica as part of a supercontinent called Columbia until its breakup 1.5 billion years ago. Continued study of ancient sedimentary basins will help test reconstructions of global supercontinents like Columbia and Rodinia.
This Presentaion will give us knowledge about our planet Earth..with regards to its Size, Shape, Inner Structure, Atmosphere Etc..
Hope you like it.. Enjoy Watching
The document summarizes research on the origin of lunar concentric craters. The researchers analyzed data from Clementine, SELENE, and LRO to study 58 known concentric craters. They identified three morphological types and found concentric craters have shallower depths and smaller rim heights than fresh simple craters, suggesting impact degradation or uplift. Distribution near mare/highland boundaries and similarities to floor-fractured craters supports igneous intrusion as the most probable formation mechanism, rather than exogenic processes like simultaneous impacts or impact into layered targets.
Geology 1: Notes on Earth's geologic forces that shape the crust with video ...Robin Seamon
The document provides an overview of geology and the structure of the Earth. It discusses the layers of the Earth including the core, mantle and crust. It describes different types of volcanoes such as shield volcanoes, cinder cone volcanoes, and composite volcanoes. It also covers plate tectonics, earthquakes, weathering and erosion.
1) Global climate models that include sophisticated cloud schemes show that tidally locked planets can develop thick water clouds near the substellar point due to strong convection. These clouds greatly increase the planetary albedo and stabilize temperatures, allowing habitability at twice the stellar flux previously thought possible.
2) The cloud feedback is stabilizing, as higher stellar flux produces stronger convection and higher albedos. Substellar clouds can block outgoing radiation, reducing the day-night temperature contrast.
3) Non-tidally locked planets do not experience this stabilizing cloud feedback, as clouds only form over parts of the tropics and mid-latitudes. Their albedo decreases with increasing stellar flux, producing a destabil
Temporal and Spatial Distribution of Wind Vector Fields and Arctic Sea-Ice Le...priscillaahn
Ice packs are constantly subject to ocean current and wind forces, causing cracks to form in rigid winter sea ice. Under enough stress, these cracks can propagate into large-scale fractures, or “leads”. Understanding how sea-ice leads form can provide insight into the net thinning of the Arctic sea-ice pack.
Leads in the Arctic sea-ice pack occur in distinct geometric patterns and sequences similar to those in rock. This suggests that the Mohr Coulomb principle of rock brittle deformation can possibly explain the spatial and temporal distribution of brittle failure in sea ice.
Gigantic submarine landslides are among the most energetic events on the Earth surface. During the
Late Pleistocene the Mediterranean Sea was the scenario of a 9 number of such events, some of whose
geological fi ngerprints are the 500 km3 mass transport deposit SL2 at the Nile delta fan (dated at ca. 110
ka BP) and the Herodotus Basing Megaturbidite (HBM, a 400 km3 deposit dated at ca. 27.1 ka BP). This
paper presents an exploratory study on the tsunamigenic potential of these slides by using a numerical
model based on the 2D depth-averaged non-linear barotropic shallow water equations.
This document summarizes an exploratory modeling study of mega-tsunamis that could have been triggered by giant submarine landslides in the Mediterranean Sea during the Late Pleistocene period. The study models three specific landslide events: the BIG'95 landslide which deposited 26 km3 off the Ebro continental slope 11.5 thousand years ago, the Herodotus Basin Megaturbidite which deposited 400 km3 in the eastern Mediterranean around 27.1 thousand years ago, and the Nile delta fan landslide SL2 which deposited around 500 km3 around 110 thousand years ago. The modeling uses numerical simulations based on shallow water equations to study the potential tsunamis generated by these landslide events, including propagation
A Giant Impact Origin for the First Subduction on EarthSérgio Sacani
Hadean zircons provide a potential record of Earth's earliest subduction 4.3 billion years ago. Itremains enigmatic how subduction could be initiated so soon after the presumably Moon‐forming giant impact(MGI). Earlier studies found an increase in Earth's core‐mantle boundary (CMB) temperature due to theaccumulation of the impactor's core, and our recent work shows Earth's lower mantle remains largely solid, withsome of the impactor's mantle potentially surviving as the large low‐shear velocity provinces (LLSVPs). Here,we show that a hot post‐impact CMB drives the initiation of strong mantle plumes that can induce subductioninitiation ∼200 Myr after the MGI. 2D and 3D thermomechanical computations show that a high CMBtemperature is the primary factor triggering early subduction, with enrichment of heat‐producing elements inLLSVPs as another potential factor. The models link the earliest subduction to the MGI with implications forunderstanding the diverse tectonic regimes of rocky planets.
This document describes experiments simulating volcanic flooding on the Moon using lunar topography data. Three similarly sized regions were artificially flooded: 1) heavily cratered terrain, 2) Hertzsprung basin, and 3) the Central Highlands. As flooding progressed, small craters were buried first followed by larger craters. Comparing the results from point source and ubiquitous flooding showed little difference in the volume of lava added or changes to crater size distributions over time. The experiments provide insights into estimating lava volumes involved in large scale resurfacing events on terrestrial planets.
The document discusses theories about the interior structure of the Earth, including the hollow Earth theory. It notes that while most models assume a solid iron core, evidence like excess heat production on Earth and anomalies in gravity measurements cast doubt on this. The document explores historical concepts of the hollow Earth from Halley and Euler, and suggests there may be inner shells, atmospheres and a possible inner sun.
This document discusses evidence that the Moon-forming impact occurred later than previously thought, at around 95 million years after the formation of the solar system. The study uses simulations of planetary formation to show a correlation between the timing of the last giant impact and the amount of mass later accreted by the planet. Comparing this to highly siderophile element abundances in Earth's mantle, which constrain the amount of late-accreted mass, the study determines the Moon-forming impact was most likely 95 million years after solar system formation. Earlier times of 40 million years or less are ruled out at a 99.9% confidence level. The simulations include both classical scenarios and scenarios where Jupiter and Saturn migrated inward early in the solar
The lithosphere is the strong, mechanically rigid outer layer of the Earth that includes the crust and upper mantle. It can be defined based on its thermal, seismic, or mechanical properties. The thickness of the lithosphere is primarily controlled by temperature, with the base occurring around the 600-800°C isotherm where ductile flow begins. Observations of plate flexure and earthquake depths generally agree with this thermal control and show the lithosphere varies in thickness from over 100km in old continental interiors to less than 15km in extended regions.
The document summarizes a seminar on subduction and abduction zones. It defines subduction as the process where one tectonic plate moves under another at a convergent boundary. Abduction is the overthrusting of oceanic crust onto continental crust at these boundaries. The document describes different types of abduction mechanisms including upwedging in subduction zones, compressional telescoping onto continental margins, and abduction occurring during continental collisions when oceanic crust is trapped between converging continents.
Artigo relata como a Terra sofreu com os impactos de ateroides a 4 bilhões de anos atrás, e como a superfície do planeta foi remodelada e os oceanos formados.
Venus and Earth have remarkably diferent
surface conditions, yet the lithospheric
thickness and heat fow on Venus may be
Earth-like. This fnding supports a tectonic
regime with limited surface mobility and
dominated by intrusive magmatism.
Mars surface radiation_environment_measured_with_curiositySérgio Sacani
The Radiation Assessment Detector on the Curiosity rover measured the radiation environment on the surface of Mars over approximately 300 days. It found:
1) The average absorbed radiation dose from galactic cosmic rays was 0.210 mGy/day, varying due to atmospheric and solar conditions.
2) An additional absorbed dose of about 50 μGy was measured from a solar particle event.
3) Extrapolating the surface measurements, the absorbed dose was estimated to be 76 mGy/year at 1 meter below the surface, decreasing substantially at greater depths.
1. The document discusses seismology, the internal structure of the Earth, plate tectonics theory, and earthquake waves.
2. The Earth's interior is composed of a crust, mantle, and core. The mantle acts as a viscous fluid that causes convection currents, which in turn exert shear stresses on tectonic plates.
3. Plate tectonics theory proposes that the lithosphere is broken into plates that move relative to each other at plate boundaries. This movement generates earthquakes and other geological activity.
First emergence of cold accretion and supermassive star formation in the earl...Sérgio Sacani
We investigate the first emergence of the so-called cold accretion, the accretion flows deeply penetrating a halo, in the early
universe with cosmological N-body/SPH simulations. We study the structure of the accretion flow and its evolution within
small halos with . 108 M with sufficiently high spatial resolutions down to ∼ 1 pc scale. While previous studies only
follow the evolution for a short period after the primordial cloud collapse, we follow the long-term evolution until the cold
accretion first appears, employing the sink particle method. We show that the cold accretion emerges when the halo mass
exceeds ∼ 2.2×107 M {(1 + 𝑧) /15}
−3/2
, the minimum halo masses above which the accretion flow penetrates halos. We further
continue simulations to study whether the cold accretion provides the dense shock waves, which have been proposed to give
birth to supermassive stars (SMSs). We find that the accretion flow eventually hits a compact disc near the halo centre, creating
dense shocks over a wide area of the disc surface. The resulting post-shock gas becomes dense and hot enough with its mass
comparable to the Jeans mass 𝑀J ∼ 104−5 M, a sufficient amount to induce the gravitational collapse, leading to the SMS
formation.
Heterogeneous delivery of silicate and metal to the Earth by large planetesimalsSérgio Sacani
After the Moon’s formation, Earth experienced a protracted bombardment by leftover planetesimals. The mass delivered during
this stage of late accretion has been estimated to be approximately 0.5% of Earth’s present mass, based on highly siderophile
element concentrations in the Earth’s mantle and the assumption that all highly siderophile elements delivered by impacts
were retained in the mantle. However, late accretion may have involved mostly large (≥ 1,500 km in diameter)—and therefore
differentiated—projectiles in which highly siderophile elements were sequestered primarily in metallic cores. Here we present
smoothed-particle hydrodynamics impact simulations that show that substantial portions of a large planetesimal’s core may
descend to the Earth’s core or escape accretion entirely. Both outcomes reduce the delivery of highly siderophile elements to
the Earth’s mantle and imply a late accretion mass that may be two to five times greater than previously thought. Further, we
demonstrate that projectile material can be concentrated within localized domains of Earth’s mantle, producing both positive
and negative 182W isotopic anomalies of the order of 10 to 100 ppm. In this scenario, some isotopic anomalies observed in terrestrial
rocks can be explained as products of collisions after Moon formation.
1) New data from the GRAIL gravity mission and LOLA altimetry is helping to determine the structure of the lunar highlands crust.
2) Preliminary GRAIL gravity models show noise levels are lower than expected, indicating signals exist at even shorter wavelengths than planned.
3) Combined analysis of gravity and topography data can provide insights into crustal thickness, elastic properties of the lithosphere, and the thermal state during and after bombardment.
Different Martian Crustal Seismic Velocities across the Dichotomy Boundary fr...Sérgio Sacani
Article This article is protected by copyright. All rights reserved.
Abstract
We have observed both minor-arc (R1) and major-arc (R2) Rayleigh waves for the largest marsquake (magnitude
of 4.7 ± 0.2) ever recorded. Along the R1 path (in the lowlands), inversion results show that a simple, two-layer
model with an interface located at 21 - 29 km and an upper crustal shear-wave velocity of 3.05 - 3.17 km/s can fit the
group velocity measurements. Along the R2 path, observations can be explained by upper crustal thickness models
constrained from gravity data and upper crustal shear-wave velocities of 2.61 - 3.27 km/s and 3.28 - 3.52 km/s in the
lowlands and highlands, respectively. The shear-wave velocity being faster in the highlands than in the lowlands
indicates the possible existence of sedimentary rocks, and relatively higher porosity in the lowlands.
Fizzy Super-Earths: Impacts of Magma Composition on the Bulk Density and Stru...Sérgio Sacani
Lava worlds are a potential emerging population of Super-Earths that are on close-in orbits around their host stars,
with likely partially molten mantles. To date, few studies have addressed the impact of magma on the observed
properties of a planet. At ambient conditions, magma is less dense than solid rock; however, it is also more
compressible with increasing pressure. Therefore, it is unclear how large-scale magma oceans affect planet
observables, such as bulk density. We update ExoPlex, a thermodynamically self-consistent planet interior
software, to include anhydrous, hydrous (2.2 wt% H2O), and carbonated magmas (5.2 wt% CO2). We find that
Earth-like planets with magma oceans larger than ∼1.5 R⊕ and ∼3.2 M⊕ are modestly denser than an equivalentmass
solid planet. From our model, three classes of mantle structures emerge for magma ocean planets: (1) a
mantle magma ocean, (2) a surface magma ocean, and (3) one consisting of a surface magma ocean, a solid rock
layer, and a basal magma ocean. The class of planets in which a basal magma ocean is present may sequester
dissolved volatiles on billion-year timescales, in which a 4 M⊕ mass planet can trap more than 130 times the mass
of water than in Earth’s present-day oceans and 1000 times the carbon in the Earth’s surface and crust.
This document summarizes active continental margins, where a continental plate overrides an oceanic plate being subducted. It focuses on the Andes as the archetypal example, describing three volcanic zones (northern, central, southern). The central zone contains thicker Precambrian crust and produces more silica-rich magmas compared to island arcs. Active volcanism occurs where subduction is steep (~30°) but not where aseismic ridges cause shallow subduction (<10°). Magmas result from mantle and crustal melting, interacting with continental crust, giving them distinct geochemical signatures. Large batholith belts were emplaced during periods of uplift and erosion when subduction shallows.
Discovery of An Apparent Red, High-Velocity Type Ia Supernova at 𝐳 = 2.9 wi...Sérgio Sacani
We present the JWST discovery of SN 2023adsy, a transient object located in a host galaxy JADES-GS
+
53.13485
−
27.82088
with a host spectroscopic redshift of
2.903
±
0.007
. The transient was identified in deep James Webb Space Telescope (JWST)/NIRCam imaging from the JWST Advanced Deep Extragalactic Survey (JADES) program. Photometric and spectroscopic followup with NIRCam and NIRSpec, respectively, confirm the redshift and yield UV-NIR light-curve, NIR color, and spectroscopic information all consistent with a Type Ia classification. Despite its classification as a likely SN Ia, SN 2023adsy is both fairly red (
�
(
�
−
�
)
∼
0.9
) despite a host galaxy with low-extinction and has a high Ca II velocity (
19
,
000
±
2
,
000
km/s) compared to the general population of SNe Ia. While these characteristics are consistent with some Ca-rich SNe Ia, particularly SN 2016hnk, SN 2023adsy is intrinsically brighter than the low-
�
Ca-rich population. Although such an object is too red for any low-
�
cosmological sample, we apply a fiducial standardization approach to SN 2023adsy and find that the SN 2023adsy luminosity distance measurement is in excellent agreement (
≲
1
�
) with
Λ
CDM. Therefore unlike low-
�
Ca-rich SNe Ia, SN 2023adsy is standardizable and gives no indication that SN Ia standardized luminosities change significantly with redshift. A larger sample of distant SNe Ia is required to determine if SN Ia population characteristics at high-
�
truly diverge from their low-
�
counterparts, and to confirm that standardized luminosities nevertheless remain constant with redshift.
Evidence of Jet Activity from the Secondary Black Hole in the OJ 287 Binary S...Sérgio Sacani
Wereport the study of a huge optical intraday flare on 2021 November 12 at 2 a.m. UT in the blazar OJ287. In the binary black hole model, it is associated with an impact of the secondary black hole on the accretion disk of the primary. Our multifrequency observing campaign was set up to search for such a signature of the impact based on a prediction made 8 yr earlier. The first I-band results of the flare have already been reported by Kishore et al. (2024). Here we combine these data with our monitoring in the R-band. There is a big change in the R–I spectral index by 1.0 ±0.1 between the normal background and the flare, suggesting a new component of radiation. The polarization variation during the rise of the flare suggests the same. The limits on the source size place it most reasonably in the jet of the secondary BH. We then ask why we have not seen this phenomenon before. We show that OJ287 was never before observed with sufficient sensitivity on the night when the flare should have happened according to the binary model. We also study the probability that this flare is just an oversized example of intraday variability using the Krakow data set of intense monitoring between 2015 and 2023. We find that the occurrence of a flare of this size and rapidity is unlikely. In machine-readable Tables 1 and 2, we give the full orbit-linked historical light curve of OJ287 as well as the dense monitoring sample of Krakow.
Candidate young stellar objects in the S-cluster: Kinematic analysis of a sub...Sérgio Sacani
Context. The observation of several L-band emission sources in the S cluster has led to a rich discussion of their nature. However, a definitive answer to the classification of the dusty objects requires an explanation for the detection of compact Doppler-shifted Brγ emission. The ionized hydrogen in combination with the observation of mid-infrared L-band continuum emission suggests that most of these sources are embedded in a dusty envelope. These embedded sources are part of the S-cluster, and their relationship to the S-stars is still under debate. To date, the question of the origin of these two populations has been vague, although all explanations favor migration processes for the individual cluster members. Aims. This work revisits the S-cluster and its dusty members orbiting the supermassive black hole SgrA* on bound Keplerian orbits from a kinematic perspective. The aim is to explore the Keplerian parameters for patterns that might imply a nonrandom distribution of the sample. Additionally, various analytical aspects are considered to address the nature of the dusty sources. Methods. Based on the photometric analysis, we estimated the individual H−K and K−L colors for the source sample and compared the results to known cluster members. The classification revealed a noticeable contrast between the S-stars and the dusty sources. To fit the flux-density distribution, we utilized the radiative transfer code HYPERION and implemented a young stellar object Class I model. We obtained the position angle from the Keplerian fit results; additionally, we analyzed the distribution of the inclinations and the longitudes of the ascending node. Results. The colors of the dusty sources suggest a stellar nature consistent with the spectral energy distribution in the near and midinfrared domains. Furthermore, the evaporation timescales of dusty and gaseous clumps in the vicinity of SgrA* are much shorter ( 2yr) than the epochs covered by the observations (≈15yr). In addition to the strong evidence for the stellar classification of the D-sources, we also find a clear disk-like pattern following the arrangements of S-stars proposed in the literature. Furthermore, we find a global intrinsic inclination for all dusty sources of 60 ± 20◦, implying a common formation process. Conclusions. The pattern of the dusty sources manifested in the distribution of the position angles, inclinations, and longitudes of the ascending node strongly suggests two different scenarios: the main-sequence stars and the dusty stellar S-cluster sources share a common formation history or migrated with a similar formation channel in the vicinity of SgrA*. Alternatively, the gravitational influence of SgrA* in combination with a massive perturber, such as a putative intermediate mass black hole in the IRS 13 cluster, forces the dusty objects and S-stars to follow a particular orbital arrangement. Key words. stars: black holes– stars: formation– Galaxy: center– galaxies: star formation
JAMES WEBB STUDY THE MASSIVE BLACK HOLE SEEDSSérgio Sacani
The pathway(s) to seeding the massive black holes (MBHs) that exist at the heart of galaxies in the present and distant Universe remains an unsolved problem. Here we categorise, describe and quantitatively discuss the formation pathways of both light and heavy seeds. We emphasise that the most recent computational models suggest that rather than a bimodal-like mass spectrum between light and heavy seeds with light at one end and heavy at the other that instead a continuum exists. Light seeds being more ubiquitous and the heavier seeds becoming less and less abundant due the rarer environmental conditions required for their formation. We therefore examine the different mechanisms that give rise to different seed mass spectrums. We show how and why the mechanisms that produce the heaviest seeds are also among the rarest events in the Universe and are hence extremely unlikely to be the seeds for the vast majority of the MBH population. We quantify, within the limits of the current large uncertainties in the seeding processes, the expected number densities of the seed mass spectrum. We argue that light seeds must be at least 103 to 105 times more numerous than heavy seeds to explain the MBH population as a whole. Based on our current understanding of the seed population this makes heavy seeds (Mseed > 103 M⊙) a significantly more likely pathway given that heavy seeds have an abundance pattern than is close to and likely in excess of 10−4 compared to light seeds. Finally, we examine the current state-of-the-art in numerical calculations and recent observations and plot a path forward for near-future advances in both domains.
Anti-Universe And Emergent Gravity and the Dark UniverseSérgio Sacani
Recent theoretical progress indicates that spacetime and gravity emerge together from the entanglement structure of an underlying microscopic theory. These ideas are best understood in Anti-de Sitter space, where they rely on the area law for entanglement entropy. The extension to de Sitter space requires taking into account the entropy and temperature associated with the cosmological horizon. Using insights from string theory, black hole physics and quantum information theory we argue that the positive dark energy leads to a thermal volume law contribution to the entropy that overtakes the area law precisely at the cosmological horizon. Due to the competition between area and volume law entanglement the microscopic de Sitter states do not thermalise at sub-Hubble scales: they exhibit memory effects in the form of an entropy displacement caused by matter. The emergent laws of gravity contain an additional ‘dark’ gravitational force describing the ‘elastic’ response due to the entropy displacement. We derive an estimate of the strength of this extra force in terms of the baryonic mass, Newton’s constant and the Hubble acceleration scale a0 = cH0, and provide evidence for the fact that this additional ‘dark gravity force’ explains the observed phenomena in galaxies and clusters currently attributed to dark matter.
The binding of cosmological structures by massless topological defectsSérgio Sacani
Assuming spherical symmetry and weak field, it is shown that if one solves the Poisson equation or the Einstein field
equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
field capable of driving flat rotation (i.e. Keplerian circular orbits at a constant speed for all radii) of test masses on a thin
spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
Gliese 12 b: A Temperate Earth-sized Planet at 12 pc Ideal for Atmospheric Tr...Sérgio Sacani
Recent discoveries of Earth-sized planets transiting nearby M dwarfs have made it possible to characterize the
atmospheres of terrestrial planets via follow-up spectroscopic observations. However, the number of such planets
receiving low insolation is still small, limiting our ability to understand the diversity of the atmospheric
composition and climates of temperate terrestrial planets. We report the discovery of an Earth-sized planet
transiting the nearby (12 pc) inactive M3.0 dwarf Gliese 12 (TOI-6251) with an orbital period (Porb) of 12.76 days.
The planet, Gliese 12 b, was initially identified as a candidate with an ambiguous Porb from TESS data. We
confirmed the transit signal and Porb using ground-based photometry with MuSCAT2 and MuSCAT3, and
validated the planetary nature of the signal using high-resolution images from Gemini/NIRI and Keck/NIRC2 as
well as radial velocity (RV) measurements from the InfraRed Doppler instrument on the Subaru 8.2 m telescope
and from CARMENES on the CAHA 3.5 m telescope. X-ray observations with XMM-Newton showed the host
star is inactive, with an X-ray-to-bolometric luminosity ratio of log 5.7 L L X bol » - . Joint analysis of the light
curves and RV measurements revealed that Gliese 12 b has a radius of 0.96 ± 0.05 R⊕,a3σ mass upper limit of
3.9 M⊕, and an equilibrium temperature of 315 ± 6 K assuming zero albedo. The transmission spectroscopy metric
(TSM) value of Gliese 12 b is close to the TSM values of the TRAPPIST-1 planets, adding Gliese 12 b to the small
list of potentially terrestrial, temperate planets amenable to atmospheric characterization with JWST.
Gliese 12 b, a temperate Earth-sized planet at 12 parsecs discovered with TES...Sérgio Sacani
We report on the discovery of Gliese 12 b, the nearest transiting temperate, Earth-sized planet found to date. Gliese 12 is a
bright (V = 12.6 mag, K = 7.8 mag) metal-poor M4V star only 12.162 ± 0.005 pc away from the Solar system with one of the
lowest stellar activity levels known for M-dwarfs. A planet candidate was detected by TESS based on only 3 transits in sectors
42, 43, and 57, with an ambiguity in the orbital period due to observational gaps. We performed follow-up transit observations
with CHEOPS and ground-based photometry with MINERVA-Australis, SPECULOOS, and Purple Mountain Observatory,
as well as further TESS observations in sector 70. We statistically validate Gliese 12 b as a planet with an orbital period of
12.76144 ± 0.00006 d and a radius of 1.0 ± 0.1 R⊕, resulting in an equilibrium temperature of ∼315 K. Gliese 12 b has excellent
future prospects for precise mass measurement, which may inform how planetary internal structure is affected by the stellar
compositional environment. Gliese 12 b also represents one of the best targets to study whether Earth-like planets orbiting cool
stars can retain their atmospheres, a crucial step to advance our understanding of habitability on Earth and across the galaxy.
The importance of continents, oceans and plate tectonics for the evolution of...Sérgio Sacani
Within the uncertainties of involved astronomical and biological parameters, the Drake Equation
typically predicts that there should be many exoplanets in our galaxy hosting active, communicative
civilizations (ACCs). These optimistic calculations are however not supported by evidence, which is
often referred to as the Fermi Paradox. Here, we elaborate on this long-standing enigma by showing
the importance of planetary tectonic style for biological evolution. We summarize growing evidence
that a prolonged transition from Mesoproterozoic active single lid tectonics (1.6 to 1.0 Ga) to modern
plate tectonics occurred in the Neoproterozoic Era (1.0 to 0.541 Ga), which dramatically accelerated
emergence and evolution of complex species. We further suggest that both continents and oceans
are required for ACCs because early evolution of simple life must happen in water but late evolution
of advanced life capable of creating technology must happen on land. We resolve the Fermi Paradox
(1) by adding two additional terms to the Drake Equation: foc
(the fraction of habitable exoplanets
with significant continents and oceans) and fpt
(the fraction of habitable exoplanets with significant
continents and oceans that have had plate tectonics operating for at least 0.5 Ga); and (2) by
demonstrating that the product of foc
and fpt
is very small (< 0.00003–0.002). We propose that the lack
of evidence for ACCs reflects the scarcity of long-lived plate tectonics and/or continents and oceans on
exoplanets with primitive life.
Climate extremes likely to drive land mammal extinction during next supercont...Sérgio Sacani
Mammals have dominated Earth for approximately 55 Myr thanks to their
adaptations and resilience to warming and cooling during the Cenozoic. All
life will eventually perish in a runaway greenhouse once absorbed solar
radiation exceeds the emission of thermal radiation in several billions of
years. However, conditions rendering the Earth naturally inhospitable to
mammals may develop sooner because of long-term processes linked to
plate tectonics (short-term perturbations are not considered here). In
~250 Myr, all continents will converge to form Earth’s next supercontinent,
Pangea Ultima. A natural consequence of the creation and decay of Pangea
Ultima will be extremes in pCO2 due to changes in volcanic rifting and
outgassing. Here we show that increased pCO2, solar energy (F⨀;
approximately +2.5% W m−2 greater than today) and continentality (larger
range in temperatures away from the ocean) lead to increasing warming
hostile to mammalian life. We assess their impact on mammalian
physiological limits (dry bulb, wet bulb and Humidex heat stress indicators)
as well as a planetary habitability index. Given mammals’ continued survival,
predicted background pCO2 levels of 410–816 ppm combined with increased
F⨀ will probably lead to a climate tipping point and their mass extinction.
The results also highlight how global landmass configuration, pCO2 and F⨀
play a critical role in planetary habitability.
Constraints on Neutrino Natal Kicks from Black-Hole Binary VFTS 243Sérgio Sacani
The recently reported observation of VFTS 243 is the first example of a massive black-hole binary
system with negligible binary interaction following black-hole formation. The black-hole mass (≈10M⊙)
and near-circular orbit (e ≈ 0.02) of VFTS 243 suggest that the progenitor star experienced complete
collapse, with energy-momentum being lost predominantly through neutrinos. VFTS 243 enables us to
constrain the natal kick and neutrino-emission asymmetry during black-hole formation. At 68% confidence
level, the natal kick velocity (mass decrement) is ≲10 km=s (≲1.0M⊙), with a full probability distribution
that peaks when ≈0.3M⊙ were ejected, presumably in neutrinos, and the black hole experienced a natal
kick of 4 km=s. The neutrino-emission asymmetry is ≲4%, with best fit values of ∼0–0.2%. Such a small
neutrino natal kick accompanying black-hole formation is in agreement with theoretical predictions.
Detectability of Solar Panels as a TechnosignatureSérgio Sacani
In this work, we assess the potential detectability of solar panels made of silicon on an Earth-like
exoplanet as a potential technosignature. Silicon-based photovoltaic cells have high reflectance in the
UV-VIS and in the near-IR, within the wavelength range of a space-based flagship mission concept
like the Habitable Worlds Observatory (HWO). Assuming that only solar energy is used to provide
the 2022 human energy needs with a land cover of ∼ 2.4%, and projecting the future energy demand
assuming various growth-rate scenarios, we assess the detectability with an 8 m HWO-like telescope.
Assuming the most favorable viewing orientation, and focusing on the strong absorption edge in the
ultraviolet-to-visible (0.34 − 0.52 µm), we find that several 100s of hours of observation time is needed
to reach a SNR of 5 for an Earth-like planet around a Sun-like star at 10pc, even with a solar panel
coverage of ∼ 23% land coverage of a future Earth. We discuss the necessity of concepts like Kardeshev
Type I/II civilizations and Dyson spheres, which would aim to harness vast amounts of energy. Even
with much larger populations than today, the total energy use of human civilization would be orders of
magnitude below the threshold for causing direct thermal heating or reaching the scale of a Kardashev
Type I civilization. Any extraterrrestrial civilization that likewise achieves sustainable population
levels may also find a limit on its need to expand, which suggests that a galaxy-spanning civilization
as imagined in the Fermi paradox may not exist.
Jet reorientation in central galaxies of clusters and groups: insights from V...Sérgio Sacani
Recent observations of galaxy clusters and groups with misalignments between their central AGN jets
and X-ray cavities, or with multiple misaligned cavities, have raised concerns about the jet – bubble
connection in cooling cores, and the processes responsible for jet realignment. To investigate the
frequency and causes of such misalignments, we construct a sample of 16 cool core galaxy clusters and
groups. Using VLBA radio data we measure the parsec-scale position angle of the jets, and compare
it with the position angle of the X-ray cavities detected in Chandra data. Using the overall sample
and selected subsets, we consistently find that there is a 30% – 38% chance to find a misalignment
larger than ∆Ψ = 45◦ when observing a cluster/group with a detected jet and at least one cavity. We
determine that projection may account for an apparently large ∆Ψ only in a fraction of objects (∼35%),
and given that gas dynamical disturbances (as sloshing) are found in both aligned and misaligned
systems, we exclude environmental perturbation as the main driver of cavity – jet misalignment.
Moreover, we find that large misalignments (up to ∼ 90◦
) are favored over smaller ones (45◦ ≤ ∆Ψ ≤
70◦
), and that the change in jet direction can occur on timescales between one and a few tens of Myr.
We conclude that misalignments are more likely related to actual reorientation of the jet axis, and we
discuss several engine-based mechanisms that may cause these dramatic changes.
The solar dynamo begins near the surfaceSérgio Sacani
The magnetic dynamo cycle of the Sun features a distinct pattern: a propagating
region of sunspot emergence appears around 30° latitude and vanishes near the
equator every 11 years (ref. 1). Moreover, longitudinal flows called torsional oscillations
closely shadow sunspot migration, undoubtedly sharing a common cause2. Contrary
to theories suggesting deep origins of these phenomena, helioseismology pinpoints
low-latitude torsional oscillations to the outer 5–10% of the Sun, the near-surface
shear layer3,4. Within this zone, inwardly increasing differential rotation coupled with
a poloidal magnetic field strongly implicates the magneto-rotational instability5,6,
prominent in accretion-disk theory and observed in laboratory experiments7.
Together, these two facts prompt the general question: whether the solar dynamo is
possibly a near-surface instability. Here we report strong affirmative evidence in stark
contrast to traditional models8 focusing on the deeper tachocline. Simple analytic
estimates show that the near-surface magneto-rotational instability better explains
the spatiotemporal scales of the torsional oscillations and inferred subsurface
magnetic field amplitudes9. State-of-the-art numerical simulations corroborate these
estimates and reproduce hemispherical magnetic current helicity laws10. The dynamo
resulting from a well-understood near-surface phenomenon improves prospects
for accurate predictions of full magnetic cycles and space weather, affecting the
electromagnetic infrastructure of Earth.
Skybuffer SAM4U tool for SAP license adoptionTatiana Kojar
Manage and optimize your license adoption and consumption with SAM4U, an SAP free customer software asset management tool.
SAM4U, an SAP complimentary software asset management tool for customers, delivers a detailed and well-structured overview of license inventory and usage with a user-friendly interface. We offer a hosted, cost-effective, and performance-optimized SAM4U setup in the Skybuffer Cloud environment. You retain ownership of the system and data, while we manage the ABAP 7.58 infrastructure, ensuring fixed Total Cost of Ownership (TCO) and exceptional services through the SAP Fiori interface.
Generating privacy-protected synthetic data using Secludy and MilvusZilliz
During this demo, the founders of Secludy will demonstrate how their system utilizes Milvus to store and manipulate embeddings for generating privacy-protected synthetic data. Their approach not only maintains the confidentiality of the original data but also enhances the utility and scalability of LLMs under privacy constraints. Attendees, including machine learning engineers, data scientists, and data managers, will witness first-hand how Secludy's integration with Milvus empowers organizations to harness the power of LLMs securely and efficiently.
leewayhertz.com-AI in predictive maintenance Use cases technologies benefits ...alexjohnson7307
Predictive maintenance is a proactive approach that anticipates equipment failures before they happen. At the forefront of this innovative strategy is Artificial Intelligence (AI), which brings unprecedented precision and efficiency. AI in predictive maintenance is transforming industries by reducing downtime, minimizing costs, and enhancing productivity.
Building Production Ready Search Pipelines with Spark and MilvusZilliz
Spark is the widely used ETL tool for processing, indexing and ingesting data to serving stack for search. Milvus is the production-ready open-source vector database. In this talk we will show how to use Spark to process unstructured data to extract vector representations, and push the vectors to Milvus vector database for search serving.
Unlock the Future of Search with MongoDB Atlas_ Vector Search Unleashed.pdfMalak Abu Hammad
Discover how MongoDB Atlas and vector search technology can revolutionize your application's search capabilities. This comprehensive presentation covers:
* What is Vector Search?
* Importance and benefits of vector search
* Practical use cases across various industries
* Step-by-step implementation guide
* Live demos with code snippets
* Enhancing LLM capabilities with vector search
* Best practices and optimization strategies
Perfect for developers, AI enthusiasts, and tech leaders. Learn how to leverage MongoDB Atlas to deliver highly relevant, context-aware search results, transforming your data retrieval process. Stay ahead in tech innovation and maximize the potential of your applications.
#MongoDB #VectorSearch #AI #SemanticSearch #TechInnovation #DataScience #LLM #MachineLearning #SearchTechnology
Digital Marketing Trends in 2024 | Guide for Staying AheadWask
https://www.wask.co/ebooks/digital-marketing-trends-in-2024
Feeling lost in the digital marketing whirlwind of 2024? Technology is changing, consumer habits are evolving, and staying ahead of the curve feels like a never-ending pursuit. This e-book is your compass. Dive into actionable insights to handle the complexities of modern marketing. From hyper-personalization to the power of user-generated content, learn how to build long-term relationships with your audience and unlock the secrets to success in the ever-shifting digital landscape.
Skybuffer AI: Advanced Conversational and Generative AI Solution on SAP Busin...Tatiana Kojar
Skybuffer AI, built on the robust SAP Business Technology Platform (SAP BTP), is the latest and most advanced version of our AI development, reaffirming our commitment to delivering top-tier AI solutions. Skybuffer AI harnesses all the innovative capabilities of the SAP BTP in the AI domain, from Conversational AI to cutting-edge Generative AI and Retrieval-Augmented Generation (RAG). It also helps SAP customers safeguard their investments into SAP Conversational AI and ensure a seamless, one-click transition to SAP Business AI.
With Skybuffer AI, various AI models can be integrated into a single communication channel such as Microsoft Teams. This integration empowers business users with insights drawn from SAP backend systems, enterprise documents, and the expansive knowledge of Generative AI. And the best part of it is that it is all managed through our intuitive no-code Action Server interface, requiring no extensive coding knowledge and making the advanced AI accessible to more users.
Monitoring and Managing Anomaly Detection on OpenShift.pdfTosin Akinosho
Monitoring and Managing Anomaly Detection on OpenShift
Overview
Dive into the world of anomaly detection on edge devices with our comprehensive hands-on tutorial. This SlideShare presentation will guide you through the entire process, from data collection and model training to edge deployment and real-time monitoring. Perfect for those looking to implement robust anomaly detection systems on resource-constrained IoT/edge devices.
Key Topics Covered
1. Introduction to Anomaly Detection
- Understand the fundamentals of anomaly detection and its importance in identifying unusual behavior or failures in systems.
2. Understanding Edge (IoT)
- Learn about edge computing and IoT, and how they enable real-time data processing and decision-making at the source.
3. What is ArgoCD?
- Discover ArgoCD, a declarative, GitOps continuous delivery tool for Kubernetes, and its role in deploying applications on edge devices.
4. Deployment Using ArgoCD for Edge Devices
- Step-by-step guide on deploying anomaly detection models on edge devices using ArgoCD.
5. Introduction to Apache Kafka and S3
- Explore Apache Kafka for real-time data streaming and Amazon S3 for scalable storage solutions.
6. Viewing Kafka Messages in the Data Lake
- Learn how to view and analyze Kafka messages stored in a data lake for better insights.
7. What is Prometheus?
- Get to know Prometheus, an open-source monitoring and alerting toolkit, and its application in monitoring edge devices.
8. Monitoring Application Metrics with Prometheus
- Detailed instructions on setting up Prometheus to monitor the performance and health of your anomaly detection system.
9. What is Camel K?
- Introduction to Camel K, a lightweight integration framework built on Apache Camel, designed for Kubernetes.
10. Configuring Camel K Integrations for Data Pipelines
- Learn how to configure Camel K for seamless data pipeline integrations in your anomaly detection workflow.
11. What is a Jupyter Notebook?
- Overview of Jupyter Notebooks, an open-source web application for creating and sharing documents with live code, equations, visualizations, and narrative text.
12. Jupyter Notebooks with Code Examples
- Hands-on examples and code snippets in Jupyter Notebooks to help you implement and test anomaly detection models.
Programming Foundation Models with DSPy - Meetup SlidesZilliz
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A Comprehensive Guide to DeFi Development Services in 2024Intelisync
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In 2024, we are witnessing an explosion of new DeFi projects and protocols, each pushing the boundaries of what’s possible in finance.
In summary, DeFi in 2024 is not just a trend; it’s a revolution that democratizes finance, enhances security and transparency, and fosters continuous innovation. As we proceed through this presentation, we'll explore the various components and services of DeFi in detail, shedding light on how they are transforming the financial landscape.
At Intelisync, we specialize in providing comprehensive DeFi development services tailored to meet the unique needs of our clients. From smart contract development to dApp creation and security audits, we ensure that your DeFi project is built with innovation, security, and scalability in mind. Trust Intelisync to guide you through the intricate landscape of decentralized finance and unlock the full potential of blockchain technology.
Ready to take your DeFi project to the next level? Partner with Intelisync for expert DeFi development services today!
Ocean lotus Threat actors project by John Sitima 2024 (1).pptxSitimaJohn
Ocean Lotus cyber threat actors represent a sophisticated, persistent, and politically motivated group that poses a significant risk to organizations and individuals in the Southeast Asian region. Their continuous evolution and adaptability underscore the need for robust cybersecurity measures and international cooperation to identify and mitigate the threats posed by such advanced persistent threat groups.
Ivanti’s Patch Tuesday breakdown goes beyond patching your applications and brings you the intelligence and guidance needed to prioritize where to focus your attention first. Catch early analysis on our Ivanti blog, then join industry expert Chris Goettl for the Patch Tuesday Webinar Event. There we’ll do a deep dive into each of the bulletins and give guidance on the risks associated with the newly-identified vulnerabilities.
Main news related to the CCS TSI 2023 (2023/1695)Jakub Marek
An English 🇬🇧 translation of a presentation to the speech I gave about the main changes brought by CCS TSI 2023 at the biggest Czech conference on Communications and signalling systems on Railways, which was held in Clarion Hotel Olomouc from 7th to 9th November 2023 (konferenceszt.cz). Attended by around 500 participants and 200 on-line followers.
The original Czech 🇨🇿 version of the presentation can be found here: https://www.slideshare.net/slideshow/hlavni-novinky-souvisejici-s-ccs-tsi-2023-2023-1695/269688092 .
The videorecording (in Czech) from the presentation is available here: https://youtu.be/WzjJWm4IyPk?si=SImb06tuXGb30BEH .
This presentation provides valuable insights into effective cost-saving techniques on AWS. Learn how to optimize your AWS resources by rightsizing, increasing elasticity, picking the right storage class, and choosing the best pricing model. Additionally, discover essential governance mechanisms to ensure continuous cost efficiency. Whether you are new to AWS or an experienced user, this presentation provides clear and practical tips to help you reduce your cloud costs and get the most out of your budget.
1. Reports
/ http://www.sciencemag.org/content/early/recent / 30 May 2013 / Page 1/ 10.1126/science.1235768
High-resolution gravity data obtained from NASA’s dual Gravity
Recovery and Interior Laboratory (GRAIL) spacecraft now provide un-
precedented high-resolution measurements of the gravity anomalies
associated with lunar impact basins (1). These gravity anomalies are the
most striking and consistent features of the Moon’s large-scale gravity
field. Positive gravity anomalies in basins partially filled with mare bas-
alt, such as Humorum (Fig. 1), have been known since 1968, when lunar
mass concentrations or “mascons” were discovered (2). Mascons have
subsequently been identified in association with impact basins on Mars
(3) and Mercury (4). Previous analysis of lunar gravity and topography
data indicated that at least nine such mare basins possess central positive
anomalies exceeding that attributable to lava emplacement alone (5).
This result is confirmed by GRAIL observations over basins that lack
basaltic infilling, such as Freundlich-Sharanov (Fig. 1), which are also
characterized by a central positive free-air gravity anomaly surrounded
by a concentric gravity low. These positive anomalies indicate an excess
of subsurface mass beyond that required for isostatic (mass) balance—a
“superisostatic” state. Mascon formation seems ubiquitous in lunar ba-
sins, whether mare-filled or not, despite their formation by impacts (a
process of mass removal that leaves a topographic low, which normally
implies a negative gravity anomaly), making mascons one of the oldest
puzzles of lunar geophysics. Their elucidation is one of the goals of the
GRAIL mission.
The gravity anomaly structure of lunar mascon basins was previous-
ly attributed to mantle rebound during collapse of the transient crater
cavity (5, 6). This process requires a lithosphere beneath the basin capa-
ble of supporting a superisostatic load immediately after impact, a pro-
posal that conflicts with the expectation that post-impact temperatures
were sufficiently high to melt both crustal and mantle rocks (7). Alterna-
tively, it was proposed (8) that mascons are created by flexural uplift of
a thickened annulus of subisostatic (a deficiency of the subsurface mass
required for isostasy) crust surrounding
the basin, concomitantly lifting the
basin interior as it cooled and the un-
derlying lithosphere became stronger.
This alternative model emphasizes the
annulus of anomalously low gravita-
tional acceleration surrounding all mas-
cons (Fig. 1) (1, 9, 10), a feature
previously attributed to thickened crust
(5, 6) or perhaps brecciation of the crust
during impact. Many mascons also
exhibit an annulus of positive gravita-
tional acceleration surrounding the
annulus of negative gravity anomaly, so
the gravity structure of most lunar ba-
sins resembles a bulls-eye target (Fig.
1).
The role of uplift in the formation
of mascon basins has been difficult to
test because little is known about the
mechanical state of basins immediately
after cavity collapse. Here we couple
GRAIL gravity and lunar topography
data from the Lunar Orbiter Laser Al-
timeter (LOLA) (11) with numerical
modeling to show that the gravity
anomaly pattern of a mascon is the
natural consequence of impact crater
excavation in the warm Moon, followed
by post-impact isostatic adjustment (12)
during cooling and contraction (13) of a
voluminous melt pool. In mare-filled
basins this stage in basin evolution was followed by emplacement of
mare-basalt lavas and associated subsidence and lithospheric flexure.
We used the axisymmetric iSALE hydrocode (14–16) to simulate the
process of crater excavation and collapse. Our models used a typical
lunar impact velocity of 15 km/s (17) and a two-layer target simulating a
gabbroic lunar crust (density = 2550 kg/m3
; 19) and a dunite mantle
(3200 kg/m3
). Our objective was to simulate the cratering process that
led to the Freundlich-Sharanov and Humorum basins, which are located
in areas where the crustal thickness is 40 and 25 km, respectively, as
inferred from GRAIL and LOLA observations (19). We sought a combi-
nation of impactor diameter and lunar thermal gradient that yielded an
annulus of thickened crust at a radius of ~200 km, consistent with the
annulus of negative free-air gravity anomaly around those basins.
The dependence of material strength on temperature and pressure
has the most marked effect on the formation of large impact basins (20).
With little certainty regarding the temperature–depth profile of the early
Moon or the diameter of the impactor, we considered impactor diameters
ranging from 30 to 80 km and three possible shallow thermal gradients
(21), 10, 20, and 30 K/km, from a 300 K surface. To avoid melted mate-
rial in the mantle, the thermal profile was assumed to follow that for a
subsolidus convective regime (0.05 K/km adiabat) at temperatures above
1300 K. We found that impact at vertical incidence of a 50-km-diameter
impactor in conjunction with a 30 K/km initial thermal gradient best
matched the extent of the annular gravity low and led to an increase in
crustal thickness of 10–15 km at a radial distance of 200–260 km from
both basin centers (Fig. 2), despite the differences in initial crustal thick-
ness (22).
A crucial aspect of the model is the formation of the subisostatic col-
lar of thickened crust surrounding the deep central pool of melted mantle
rock. The crust is thickened as the impact ejects crustal material onto the
cool, strong preexisting crust. The ejected material forms a wedge ap-
The Origin of Lunar Mascon Basins
H. J. Melosh,1,2
* Andrew M. Freed,1
Brandon C. Johnson,2
David M.
Blair,1
Jeffrey C. Andrews-Hanna,3
Gregory A. Neumann,4
Roger J.
Phillips,5
David E. Smith,6
Sean C. Solomon,7,8
Mark A. Wieczorek,9
Maria T. Zuber6
1
Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, 550 Stadium Mall Drive,
West Lafayette, IN 47907, USA.
2
Department of Physics, Purdue University, 525 Northwestern Avenue,
West Lafayette, IN 47907, USA.
3
Department of Geophysics, Colorado School of Mines, 1500 Illinois
Street, Golden, CO 80401–1887, USA.
4
Solar System Exploration Division, NASA Goddard Space Flight
Center, Greenbelt, MD 20771, USA.
5
Planetary Science Directorate, Southwest Research Institute,
Boulder, CO 80302, USA.
6
Department of Earth, Atmospheric and Planetary Sciences, Massachusetts
Institute of Technology, Cambridge, MA 02139–4307, USA.
7
Department of Terrestrial Magnetism,
Carnegie Institution of Washington, Washington, DC 20015, USA.
8
Lamont-Doherty Earth Observatory,
Columbia University, Palisades, NY 10964, USA.
9
Institut de Physique du Globe de Paris, Sorbonne Paris
Cité, Université Paris Diderot, 75205 Paris Cedex 13, France.
*Corresponding author. E-mail: jmelosh@purdue.edu
High-resolution gravity data from the GRAIL spacecraft have clarified the origin of
lunar mascons. Free-air gravity anomalies over lunar impact basins display bulls-
eye patterns consisting of a central positive (mascon) anomaly, a surrounding
negative collar, and a positive outer annulus. We show that this pattern results from
impact basin excavation and collapse followed by isostatic adjustment and cooling
and contraction of a voluminous melt pool. We employed a hydrocode to simulate
the impact and a self-consistent finite-element model to simulate the subsequent
viscoelastic relaxation and cooling. The primary parameters controlling the modeled
gravity signatures of mascon basins are the impactor energy, the lunar thermal
gradient at the time of impact, the crustal thickness, and the extent of volcanic fill.
onJune2,2013www.sciencemag.orgDownloadedfrom
2. / http://www.sciencemag.org/content/early/recent / 30 May 2013 / Page 2/ 10.1126/science.1235768
proximately 15 km thick at its inner edge that thins with increasing dis-
tance from the center. The preexisting crust is drawn downward and into
the transient crater cavity due to a combination of loading by ejecta and
inward flow of the underlying mantle, deforming it into a subisostatic
configuration. This arrangement is maintained by the frictional strength
of the cool (but thoroughly shattered) crust, as well as by the viscoelastic
mantle that requires time to relax. It is the subsequent relaxation of the
mantle that leads to a later isostatic adjustment. The result is a thick,
low-density crustal collar around the central hot melt pool that is initially
prevented from mechanically rebounding from its disequilibrium state.
The higher thermal gradient of 30 K/km, somewhat counter-intuitively,
yields a thicker subisostatic crustal collar than the thermal gradients of
10 and 20 K/km. This difference occurs because the weaker mantle as-
sociated with a higher thermal gradient flows more readily during the
collapse of the transient crater, exerting less inward drag on the crustal
collar, which consequently experiences less stretching and thinning.
Calculations suggest that the impact into relatively thin crust at Hu-
morum basin fully exposed mantle material in the central region of the
basin (Fig. 2B), whereas a ~15-km-thick cap of crustal material flowed
over the central region of the Freundlich-Sharanov basin (Fig. 2A). This
crustal cap material was warm weak lower crustal material that migrated
to the basin center during crater collapse (Fig. S1). At the end of the
crater collapse process, the basins (defined by their negative topography)
were 4–5 km deep out to 150 km from the basin center, with shallow
negative topography continuing to a radial distance of 350–400 km,
approximately twice the excavation radius. A substantial melt pool, de-
fined as mantle at temperatures above 1500 K, developed in both basins.
This melt pool extended out to ~150 km from the basin center and to
more than 100 km depth (Fig. 2).
To model the subsequent evolution of the basins, we used the finite
element code Abaqus (23, 24). We developed axisymmetric models of
the Humorum and Freundlich-Sharanov basins from the hydrocode out-
put, adjusting the thermal structure of the melt to account for rapid post-
impact convection and thermal homogenization of the melt pool. The
density of solid and liquid silicate material was calculated from the bulk
composition of the silicate Moon (22, 25).
Our models (Figs. 1, C and D) show that the depressed basin topog-
raphy, the thickened crustal collar, and the lower density of heated mate-
rial combine to create a substantial negative free-air gravity anomaly at
the basin centers (22). The post-impact free-air anomaly is slightly posi-
tive outside of the basin owing to ejecta supported by the cool, strong
crust and mantle. The overall shape of the modeled post-impact free-air
gravity anomaly is similar to that observed but is much more negative,
suggesting that the general pattern of the observed gravity anomaly is the
result of the impact, but that subsequent evolution of the basin drove the
central anomalies positive.
As the impact-heated mantle beneath the basin cooled, the pressure
gradient from its exterior to its interior drove viscoelastic flow toward
the basin center, uplifting the basin floor. The inner basin (where the
central mascon develops) cannot rise above isostatic equilibrium solely
due to forces from its own subisostatic state. However, mechanical cou-
pling between the inner and outer basin—where the collar of thickened
crust was also rising isostatically—provided additional lift to the inner
basin floor, enabling it to achieve a superisostatic state. This mechanical
coupling is achieved if the lithosphere above the melt pool thickened
sufficiently as it cooled. In the case of the Freundlich-Sharanov basin,
the 15-km-thick layer of cool crust provided an initial (if thin) litho-
sphere from the beginning, which thickened as the underlying mantle
cooled. For Humorum basin, the melt pool reached the surface and thus
there was initially no lithosphere, although one developed during cool-
ing. Our calculations show that if the viscosity of the mantle outside the
melt pool is consistent with dry dunite, its viscoelastic strength would
delay isostatic uplift of the basin floor such that lithospheres sufficient
for development of a mascon develop over the melt pools in both basins.
In addition to these isostatic forces, cooling increases the density of the
melt through contraction; given a strong lithosphere that hinders the
sinking of this higher-density material, this process further increases the
gravity anomaly at the basin center. The net effect is that isostatic uplift
of the surrounding depressed surface topography and crustal collar,
combined with cooling and contraction of the melt pool, create the cen-
tral positive free-air anomaly. The flexural strength that enables the inner
basin to rise into a superisostatic state prevented the outer basin from
fully rising to isostatic equilibrium, leaving the observed ring of negative
free-air anomaly that surrounds the inner basin.
Isostatic uplift raised the surface topography of the Freundlich-
Sharanov basin by ~2 km at the center of the basin (Fig. 3A). These
effects place the final basin depth at just over 4 km, consistent with
LOLA elevation measurements (11, 22). For the Humorum basin, the
inner basin was calculated to rise ~3 km (Fig. 3B). This uplift distribu-
tion would have left the Humorum basin ~4 km deep prior to mare fill.
Infilling of a 3-km-thick mare unit and associated subsidence brings the
floor depth of the Humorum basin to just over 1.5 km deep, modestly
deeper then the 1 km depth measured by LOLA (22).
The free-air gravity anomalies of both basins increased markedly af-
ter crater collapse as a result of cooling and isostatic uplift. The free-air
anomaly of the Freundlich-Sharanov basin is predicted to have risen to a
positive 80 mGal in the inner basin and -200 mGal in the outer basin
above the thickened crust, in excellent agreement with GRAIL observa-
tions (1) (red line in Fig. 1C). Furthermore, the model predicts an outer
annulus of positive anomalies, also in agreement with observations. A
similar post-impact increase in the free-air anomaly is observed in our
model of Humorum basin (red line in Fig. 1D), although this gravity
anomaly cannot be verified because the Humorum basin was subse-
quently partially filled with mare basalt. Our results support the infer-
ence that lunar basins possess a positive gravity anomaly in excess of the
mare load (5). As a final step in our analysis, we emplaced a mare unit 3
km thick and 150 km in radius (tapered to zero thickness over the outer-
most 50 km in radial distance), within the Humorum basin. The addition
of the mare increases the mascon at the center of the Humorum basin to
320 mGal (blue line in Fig, 1D), matching GRAIL measurements (1).
This basin evolution scenario depends primarily on the energy of the
impactor, the thermal gradient of the Moon at the time of the impact, and
the thickness of the crust. A high thermal gradient enables weaker man-
tle to flow more readily during the collapse of the transient crater, result-
ing in less inward motion and thinning of the crust. In contrast to
hydrocode parameters that control crater excavation and collapse, such
as the energy of the impactor and the initial thermal gradient, the close
match of our predicted free-air gravity anomalies to those observed by
GRAIL is not a product of finding a special combination of finite-
element model parameters associated with isostatic uplift and cooling.
These processes are controlled by the evolution of the density and vis-
cosity structure in the model, which follow from the mineralogy of the
lunar crust and mantle and the evolution of temperature as the region
conductively cools.
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Acknowledgments: The GRAIL mission is supported by NASA’s
Discovery Program and is performed under contract to the
Massachusetts Institute of Technology and the Jet Propulsion
Laboratory. The Lunar Reconnaissance Orbiter Lunar Orbiter Laser
Altimeter (LOLA) investigation is supported by the NASA Science
Mission Directorate under contract to the NASA Goddard Space
Flight Center and Massachusetts Institute of Technology. Data from
the GRAIL and LOLA missions have been deposited in the
Geosciences Node of NASA’s Planetary Data System.
Supplementary Materials
www.sciencemag.org/cgi/content/full/science.1235768/DC1
Supplementary Text
Figs. S1 to S6
Tables S1 to S4
References (26–43)
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28 January 2013; accepted 16 May 2013
Published online 30 May 2013
10.1126/science.1235768
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Fig. 1. Free-air gravity anomalies over (A) the mare-free Freundlich-Sharanov basin (radius to the center of the free-air
gravity low: 215 km) and (B) the mare-filled Humorum basin (radius to the center of the annular free-air gravity low: 215
km) from GRAIL observations (1). (C and D) Comparison of observed and calculated free-air gravity anomalies for the
Freundlich-Sharanov and Humorum basins, respectively. The observed anomalies and associated one-standard-deviation
ranges were derived from averages of the data within concentric rings at different radial distances. The black lines
represent the predicted gravity anomaly just after impact and transient cavity collapse, from the hydrocode calculation. The
red lines represent the predicted anomaly after uplift following isostatic response and cooling, appropriate for comparison
to the Freundlich-Sharanov data. The blue line in (D) represents the predicted gravity anomaly after mare emplacement in
the Humorum basin and is appropriate for comparison to data from that basin.
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Fig. 2. Vertical cross section of crust and mantle geometry and thermal structure after crater collapse (2
hours after impact) for the (A) Freundlich-Sharanov basin (40-km-thick original crust) and (B) Humorum basin
(25-km-thick original crust), according to the hydrocode calculation.
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Fig. 3. Vertical displacement calculated by the finite element model relative to the initial post-crater-collapse
configuration predicted by the hydrocode for the unfilled (A) Freundlich-Sharanov basin (B) Humorum basin.
The deformation is exaggerated by a factor of 10.
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