This document provides background information on air blasts produced by near-Earth asteroids. It summarizes current estimates of the properties of the February 2013 Chelyabinsk event based on preliminary data. The event is estimated to have involved a 17 meter asteroid with a velocity of 40,000 mph that exploded 15-20 km above the Earth's surface with an energy equivalent to 500 kilotons of TNT. The briefing also discusses past asteroid air blast events like Tunguska and Barringer Crater for comparison. It examines the components of impact air blasts and how blast areas scale with the size of the impacting object.
1. The formation and evolution of the Solar System began about 4.57 billion years ago with the gravitational collapse of a small part of a giant molecular cloud. Most of the collapsing mass collected in the center to form the Sun, while the rest flattened into a protoplanetary disk from which the planets, moons, asteroids and other small bodies formed.
2. According to the nebular hypothesis, Earth formed about 4.54 billion years ago from accretion of planetary material in the solar nebula. Within the first 100-200 million years, early Earth had formed extensive oceans and seas.
3. Key events in the development of early Earth included the formation of its layered internal structure through the sinking of
The document provides an introduction to seismology and the study of earthquakes. It discusses the formation of the Earth and its layers. The Earth is divided into the inner core, outer core, mantle, and crust. The core is mostly iron and nickel, the mantle consists of silicate compounds, and the crust is made of less dense materials. Earthquakes are caused by the sudden movement of tectonic plates or rupture along faults. The theory of plate tectonics explains the distribution of seismic activity and ties together concepts like continental drift.
Prentice Hall Earth Science ch08 earthquakes & Layers of EarthTim Corner
1) An earthquake is caused by the sudden release of elastic energy stored in rock along faults. This causes seismic waves that can be measured by seismographs.
2) The location and size of earthquakes are determined by analyzing seismic wave arrival times and amplitudes recorded by multiple seismographs. Larger quakes are capable of more destruction through ground shaking and triggering other hazards like tsunamis and landslides.
3) Earth has a layered internal structure consisting of a crust, mantle, and core based on differences in composition and physical properties. The crust and upper mantle form the rigid lithosphere, while the lower mantle and outer core are able to flow over long timescales.
Explosive and non explosive energy sources in marine acquisition ( overview )Ali M. Abdelsamad
This document discusses explosive and non-explosive energy sources used in marine seismic acquisition. Explosive sources include air guns and dynamite. Air guns work by injecting compressed air into the water to generate seismic waves, while dynamite was previously used but is being phased out. Non-explosive sources are mechanical devices like water guns, boomers, sparkers, and chirp systems. Water guns use compressed air to eject water jets. Boomers use electromagnetic induction to rapidly move metal plates. Sparkers use electrical discharge in water to create acoustic pulses. Chirp systems are electro-mechanical transducers that can output extended waveforms for better resolution.
The document discusses evidence of crustal movement on Earth including deformed rock structures and fossil evidence. It then introduces plate tectonics, describing the four main layers of Earth's structure and how the lithosphere is divided into tectonic plates that move due to convection currents in the upper mantle. Earthquakes occur along plate boundaries and faults as the plates interact and move.
is one of the first steps in
searching for oil and gas resources that directly
affects the land and the landowners Seismic surveys are like sonar on steroids They are based on recording the time it takes for sound waves generated by controlled energy sources .The survey usually requires people and machinery
to be on private property and may result in
disturbances of the land such as the clearing of
trees
Surface ocean currents are driven by wind and develop large circular gyre patterns. The Coriolis effect causes currents to deflect to the right in the Northern Hemisphere. Ocean currents transfer heat between latitudes and influence global climate. Upwelling brings nutrients from deep waters to the surface. Deep ocean circulation involves dense, salty water sinking and flowing in conveyor belt-like patterns. Waves are generated by wind and break along shorelines, causing erosion. Tides are daily changes in ocean height caused by gravitational forces from the Moon and Sun. Shoreline features such as cliffs, bars, and beaches form through the interacting processes of erosion and deposition by waves.
Seismic waves are the waves of energy caused by the sudden breaking of rock within the earth or an explosion.
Response of material to the arrival of energy fronts released by rupture.
Energy that travels through the earth and is recorded on seismographs.
1. The formation and evolution of the Solar System began about 4.57 billion years ago with the gravitational collapse of a small part of a giant molecular cloud. Most of the collapsing mass collected in the center to form the Sun, while the rest flattened into a protoplanetary disk from which the planets, moons, asteroids and other small bodies formed.
2. According to the nebular hypothesis, Earth formed about 4.54 billion years ago from accretion of planetary material in the solar nebula. Within the first 100-200 million years, early Earth had formed extensive oceans and seas.
3. Key events in the development of early Earth included the formation of its layered internal structure through the sinking of
The document provides an introduction to seismology and the study of earthquakes. It discusses the formation of the Earth and its layers. The Earth is divided into the inner core, outer core, mantle, and crust. The core is mostly iron and nickel, the mantle consists of silicate compounds, and the crust is made of less dense materials. Earthquakes are caused by the sudden movement of tectonic plates or rupture along faults. The theory of plate tectonics explains the distribution of seismic activity and ties together concepts like continental drift.
Prentice Hall Earth Science ch08 earthquakes & Layers of EarthTim Corner
1) An earthquake is caused by the sudden release of elastic energy stored in rock along faults. This causes seismic waves that can be measured by seismographs.
2) The location and size of earthquakes are determined by analyzing seismic wave arrival times and amplitudes recorded by multiple seismographs. Larger quakes are capable of more destruction through ground shaking and triggering other hazards like tsunamis and landslides.
3) Earth has a layered internal structure consisting of a crust, mantle, and core based on differences in composition and physical properties. The crust and upper mantle form the rigid lithosphere, while the lower mantle and outer core are able to flow over long timescales.
Explosive and non explosive energy sources in marine acquisition ( overview )Ali M. Abdelsamad
This document discusses explosive and non-explosive energy sources used in marine seismic acquisition. Explosive sources include air guns and dynamite. Air guns work by injecting compressed air into the water to generate seismic waves, while dynamite was previously used but is being phased out. Non-explosive sources are mechanical devices like water guns, boomers, sparkers, and chirp systems. Water guns use compressed air to eject water jets. Boomers use electromagnetic induction to rapidly move metal plates. Sparkers use electrical discharge in water to create acoustic pulses. Chirp systems are electro-mechanical transducers that can output extended waveforms for better resolution.
The document discusses evidence of crustal movement on Earth including deformed rock structures and fossil evidence. It then introduces plate tectonics, describing the four main layers of Earth's structure and how the lithosphere is divided into tectonic plates that move due to convection currents in the upper mantle. Earthquakes occur along plate boundaries and faults as the plates interact and move.
is one of the first steps in
searching for oil and gas resources that directly
affects the land and the landowners Seismic surveys are like sonar on steroids They are based on recording the time it takes for sound waves generated by controlled energy sources .The survey usually requires people and machinery
to be on private property and may result in
disturbances of the land such as the clearing of
trees
Surface ocean currents are driven by wind and develop large circular gyre patterns. The Coriolis effect causes currents to deflect to the right in the Northern Hemisphere. Ocean currents transfer heat between latitudes and influence global climate. Upwelling brings nutrients from deep waters to the surface. Deep ocean circulation involves dense, salty water sinking and flowing in conveyor belt-like patterns. Waves are generated by wind and break along shorelines, causing erosion. Tides are daily changes in ocean height caused by gravitational forces from the Moon and Sun. Shoreline features such as cliffs, bars, and beaches form through the interacting processes of erosion and deposition by waves.
Seismic waves are the waves of energy caused by the sudden breaking of rock within the earth or an explosion.
Response of material to the arrival of energy fronts released by rupture.
Energy that travels through the earth and is recorded on seismographs.
Seismic waves are waves of energy that travel through the Earth generated by earthquakes, explosions, or other processes. There are two main types of seismic waves: body waves, which travel through the Earth's interior, and surface waves, which travel along the Earth's surface. Body waves include P-waves and S-waves. P-waves are compressional waves that can travel through solid and liquid materials, while S-waves are shear waves that only travel through solids. Surface waves include Rayleigh waves and Love waves.
The document discusses the Earth's internal energy and how it causes tectonic plate movement and related geological phenomena. The main points are:
1) The Earth has internal heat from radioactive elements and impacts that causes plate tectonics and results in volcanoes, earthquakes, and mountain building.
2) Alfred Wegener proposed continental drift in 1912 to explain how the continents were once joined together before drifting apart, as evidenced by matching continental shelves.
3) The Earth's solid crust is made up of tectonic plates that move due to convection currents in the mantle, resulting in earthquakes and volcanic activity at plate boundaries.
Environmental scientists study issues like climate change, pollution, and natural resource protection. Their work involves monitoring greenhouse gases, investigating melting ice sheets, and exploring renewable energy sources like solar and wind power. They use tools like ground penetrating radar and resistivity measurements to map underground structures and contaminated soil at former industrial sites being cleaned up through remediation efforts. A variety of science backgrounds can prepare people for careers in environmental science.
Taylor proposed the concept of continental drift in 1908, hypothesizing that continents had shifted horizontally across Earth's surface over geological time. He suggested that the Arctic Sea was formed when Greenland and Siberia drifted apart, and that gaps between landmasses were filled by water to form oceans like the Atlantic and Indian Ocean. Taylor's continental drift theory was one of the first attempts to explain observations that seemed to support the idea of continental plate movements.
The document provides an overview of our solar system, including:
- The terrestrial planets are small and rocky, while the Jovian planets are huge gas giants.
- The planets formed from a rotating disk of dust and gases according to the nebular theory.
- Key details are then given about each of the planets, their composition, features, and conditions. Minor members like asteroids, comets, meteoroids are also briefly described.
The universe contains billions of galaxies, each with billions of stars. A galaxy is a group of stars held together by gravity, and there are three main types of galaxies: spiral, elliptical, and irregular. Stars are formed from the collapse of large clouds of dust and gas under the force of gravity. Our solar system contains eight planets that orbit the Sun, including Earth. Copernicus first proposed that planets orbit the Sun, while Kepler developed the three laws of planetary motion describing their elliptical orbits and periods.
- The document discusses the heliocentric model of the solar system proposed by Copernicus and refined by Kepler, including Kepler's three laws of planetary motion. It then provides an overview of the formation of the solar system according to the nebular hypothesis and describes the key characteristics of planets Mercury through Saturn, including their orbits, compositions, atmospheres, moons, and surfaces. The solar system is understood to have formed from a large nebula that collapsed under gravity to form the Sun and planets approximately 4.6 billion years ago.
This document summarizes the formation of the solar system according to the core accretion model. It explains that the solar system began as a solar nebula that collapsed under gravity to form the sun. Heavier elements near the sun merged to form terrestrial planets, while lighter elements further from the sun formed gas giants. The earliest Earth had a hot molten surface and atmosphere of gases like hydrogen and carbon dioxide. Over time, the Earth cooled and developed layers, water was introduced via asteroids, and a water cycle, plate tectonics, and life emerged.
Origin and interiors of the earth LECTURE OF CIVIL ENGINEERING DRAWINGSafiullah Khan
This document provides an overview of engineering geology and the interior structure of Earth. It discusses:
- Engineering geology as the application of geology to civil engineering projects.
- The interior structure of Earth, including the crust, mantle (with upper, lower, and outer layers), liquid outer core, and solid inner core.
- Theories for the origin of Earth, including the nebular hypothesis of Kant and Laplace where Earth formed from a contracting gas cloud/nebula around the sun.
The document discusses the different spheres or layers of the Earth. It begins by describing the Earth and its color compared to other planets. It then discusses the four subsystems that make up Earth and flow of matter and energy between them. It identifies the layers of the Earth and differentiates between them. Finally, it discusses natural waters and the water cycle.
The document summarizes the formation and early history of the Earth based on radiometric dating evidence. It describes how the Earth formed over 50-100 million years through the accumulation of planetesimals, creating intense bombardment that kept the surface molten. Around 4 billion years ago, the Moon formed from a collision that ejected material into orbit. Life first emerged in the early Earth's carbon dioxide-rich atmosphere and began altering the atmosphere through photosynthesis.
This document discusses seismic waves and seismicity in Pakistan. It describes the different types of seismic waves including body waves like P waves and S waves, and surface waves like Rayleigh and Love waves. Their velocities and properties are explained. The seismicity of Pakistan is then summarized, noting major earthquakes in 2005, 2008, and 2013 that caused significant damage. Seismic zoning maps divide Pakistan into risk areas based on earthquake data.
The document discusses travelling waves and bores in the lower atmosphere, focusing on the "Morning Glory" phenomenon. It provides:
1) An overview of the Morning Glory, describing it as a spectacular low roll cloud associated with solitary wave disturbances at the leading edge of an undular bore that propagates on a low-level stable layer.
2) Details on the structure and preferred directions of travel of Morning Glory disturbances in northern Australia, as well as their genesis, demise, and relation to nocturnal solitary wave disturbances.
3) An explanation of the theoretical background involving equations like Korteweg-de Vries and Benjamin-Ono-Burgers that can model these types of atmospheric
Changes in the earth and its atmosphereSteve Bishop
The document summarizes changes to the Earth's core, mantle, crust, and atmosphere over time. It describes the theory of tectonic plates and how their movement causes earthquakes and volcanic eruptions. It explains how early theories of continental drift were rejected but later accepted when ocean floor investigations found evidence supporting plate tectonics. It also outlines how the atmosphere was initially composed of gases like carbon dioxide and methane, and how oxygen levels increased due to photosynthesis by plants and algae.
Deep underground, rocks are under constant pressure until the strain becomes too great and the rocks suddenly break, releasing seismic waves. These waves travel outward from the hypocenter in three types - P waves which push and pull, S waves which move sides to side, and L waves which cause surfaces to bob up and down. When recorded by a seismograph, the first indication of an earthquake is typically the P waves, followed by larger S waves, with surface L waves arriving last.
Continental drift is the movement of the Earth's continents relative to each other by appearing to drift across the ocean bed The speculation that continents might have 'drifted' was first put forward by Abraham Ortelius in 1596. The concept was independently and more fully developed by Alfred Wegener in 1912, but his theory was rejected for being incomplete. The idea of continental drift has been subsumed by the theory of plate tectonics which explains how the continents moveThe formation and evolution of the Solar System,
The document summarizes key facts about the dynamic Earth. It describes the different layers of the Earth including the crust, mantle, and core. The crust is divided into continental and oceanic crust of varying thicknesses. The mantle makes up most of the Earth's mass and is divided into lithosphere, asthenosphere, and mesosphere layers. The core is divided into a solid inner core and liquid outer core. The document also briefly outlines the Earth's rotation, revolution around the sun, and reasons for the seasons.
Bila Allah pun dikatakan ada KelemahanHootoh Tudia
Allah pun ada Kekurangan. Cuma kerana 4 patah perkataan sy dihukum Yahudi, dihukum Kafir dan sebagainya. www.hootoh.my Bila Allah pun dikatakan ada Kelemahan.
Seismic waves are waves of energy that travel through the Earth generated by earthquakes, explosions, or other processes. There are two main types of seismic waves: body waves, which travel through the Earth's interior, and surface waves, which travel along the Earth's surface. Body waves include P-waves and S-waves. P-waves are compressional waves that can travel through solid and liquid materials, while S-waves are shear waves that only travel through solids. Surface waves include Rayleigh waves and Love waves.
The document discusses the Earth's internal energy and how it causes tectonic plate movement and related geological phenomena. The main points are:
1) The Earth has internal heat from radioactive elements and impacts that causes plate tectonics and results in volcanoes, earthquakes, and mountain building.
2) Alfred Wegener proposed continental drift in 1912 to explain how the continents were once joined together before drifting apart, as evidenced by matching continental shelves.
3) The Earth's solid crust is made up of tectonic plates that move due to convection currents in the mantle, resulting in earthquakes and volcanic activity at plate boundaries.
Environmental scientists study issues like climate change, pollution, and natural resource protection. Their work involves monitoring greenhouse gases, investigating melting ice sheets, and exploring renewable energy sources like solar and wind power. They use tools like ground penetrating radar and resistivity measurements to map underground structures and contaminated soil at former industrial sites being cleaned up through remediation efforts. A variety of science backgrounds can prepare people for careers in environmental science.
Taylor proposed the concept of continental drift in 1908, hypothesizing that continents had shifted horizontally across Earth's surface over geological time. He suggested that the Arctic Sea was formed when Greenland and Siberia drifted apart, and that gaps between landmasses were filled by water to form oceans like the Atlantic and Indian Ocean. Taylor's continental drift theory was one of the first attempts to explain observations that seemed to support the idea of continental plate movements.
The document provides an overview of our solar system, including:
- The terrestrial planets are small and rocky, while the Jovian planets are huge gas giants.
- The planets formed from a rotating disk of dust and gases according to the nebular theory.
- Key details are then given about each of the planets, their composition, features, and conditions. Minor members like asteroids, comets, meteoroids are also briefly described.
The universe contains billions of galaxies, each with billions of stars. A galaxy is a group of stars held together by gravity, and there are three main types of galaxies: spiral, elliptical, and irregular. Stars are formed from the collapse of large clouds of dust and gas under the force of gravity. Our solar system contains eight planets that orbit the Sun, including Earth. Copernicus first proposed that planets orbit the Sun, while Kepler developed the three laws of planetary motion describing their elliptical orbits and periods.
- The document discusses the heliocentric model of the solar system proposed by Copernicus and refined by Kepler, including Kepler's three laws of planetary motion. It then provides an overview of the formation of the solar system according to the nebular hypothesis and describes the key characteristics of planets Mercury through Saturn, including their orbits, compositions, atmospheres, moons, and surfaces. The solar system is understood to have formed from a large nebula that collapsed under gravity to form the Sun and planets approximately 4.6 billion years ago.
This document summarizes the formation of the solar system according to the core accretion model. It explains that the solar system began as a solar nebula that collapsed under gravity to form the sun. Heavier elements near the sun merged to form terrestrial planets, while lighter elements further from the sun formed gas giants. The earliest Earth had a hot molten surface and atmosphere of gases like hydrogen and carbon dioxide. Over time, the Earth cooled and developed layers, water was introduced via asteroids, and a water cycle, plate tectonics, and life emerged.
Origin and interiors of the earth LECTURE OF CIVIL ENGINEERING DRAWINGSafiullah Khan
This document provides an overview of engineering geology and the interior structure of Earth. It discusses:
- Engineering geology as the application of geology to civil engineering projects.
- The interior structure of Earth, including the crust, mantle (with upper, lower, and outer layers), liquid outer core, and solid inner core.
- Theories for the origin of Earth, including the nebular hypothesis of Kant and Laplace where Earth formed from a contracting gas cloud/nebula around the sun.
The document discusses the different spheres or layers of the Earth. It begins by describing the Earth and its color compared to other planets. It then discusses the four subsystems that make up Earth and flow of matter and energy between them. It identifies the layers of the Earth and differentiates between them. Finally, it discusses natural waters and the water cycle.
The document summarizes the formation and early history of the Earth based on radiometric dating evidence. It describes how the Earth formed over 50-100 million years through the accumulation of planetesimals, creating intense bombardment that kept the surface molten. Around 4 billion years ago, the Moon formed from a collision that ejected material into orbit. Life first emerged in the early Earth's carbon dioxide-rich atmosphere and began altering the atmosphere through photosynthesis.
This document discusses seismic waves and seismicity in Pakistan. It describes the different types of seismic waves including body waves like P waves and S waves, and surface waves like Rayleigh and Love waves. Their velocities and properties are explained. The seismicity of Pakistan is then summarized, noting major earthquakes in 2005, 2008, and 2013 that caused significant damage. Seismic zoning maps divide Pakistan into risk areas based on earthquake data.
The document discusses travelling waves and bores in the lower atmosphere, focusing on the "Morning Glory" phenomenon. It provides:
1) An overview of the Morning Glory, describing it as a spectacular low roll cloud associated with solitary wave disturbances at the leading edge of an undular bore that propagates on a low-level stable layer.
2) Details on the structure and preferred directions of travel of Morning Glory disturbances in northern Australia, as well as their genesis, demise, and relation to nocturnal solitary wave disturbances.
3) An explanation of the theoretical background involving equations like Korteweg-de Vries and Benjamin-Ono-Burgers that can model these types of atmospheric
Changes in the earth and its atmosphereSteve Bishop
The document summarizes changes to the Earth's core, mantle, crust, and atmosphere over time. It describes the theory of tectonic plates and how their movement causes earthquakes and volcanic eruptions. It explains how early theories of continental drift were rejected but later accepted when ocean floor investigations found evidence supporting plate tectonics. It also outlines how the atmosphere was initially composed of gases like carbon dioxide and methane, and how oxygen levels increased due to photosynthesis by plants and algae.
Deep underground, rocks are under constant pressure until the strain becomes too great and the rocks suddenly break, releasing seismic waves. These waves travel outward from the hypocenter in three types - P waves which push and pull, S waves which move sides to side, and L waves which cause surfaces to bob up and down. When recorded by a seismograph, the first indication of an earthquake is typically the P waves, followed by larger S waves, with surface L waves arriving last.
Continental drift is the movement of the Earth's continents relative to each other by appearing to drift across the ocean bed The speculation that continents might have 'drifted' was first put forward by Abraham Ortelius in 1596. The concept was independently and more fully developed by Alfred Wegener in 1912, but his theory was rejected for being incomplete. The idea of continental drift has been subsumed by the theory of plate tectonics which explains how the continents moveThe formation and evolution of the Solar System,
The document summarizes key facts about the dynamic Earth. It describes the different layers of the Earth including the crust, mantle, and core. The crust is divided into continental and oceanic crust of varying thicknesses. The mantle makes up most of the Earth's mass and is divided into lithosphere, asthenosphere, and mesosphere layers. The core is divided into a solid inner core and liquid outer core. The document also briefly outlines the Earth's rotation, revolution around the sun, and reasons for the seasons.
Bila Allah pun dikatakan ada KelemahanHootoh Tudia
Allah pun ada Kekurangan. Cuma kerana 4 patah perkataan sy dihukum Yahudi, dihukum Kafir dan sebagainya. www.hootoh.my Bila Allah pun dikatakan ada Kelemahan.
Copyright 2010
Original Music by Grace H Ma "Answering Your Call" (2010)
Slides describing my artistic philosophy. Adapted from a classroom thesis on modern art and the perspective it offers.
Undang-undang ini mengatur tentang perbendaharaan negara yang mencakup pengelolaan dan pertanggungjawaban keuangan negara berdasarkan APBN dan APBD. Dokumen ini menjelaskan tentang pengertian istilah, ruang lingkup, asas umum, pejabat perbendaharaan negara termasuk pengguna anggaran, bendahara umum negara/daerah.
PERANCANGAN APLIKASI OJEK PANGKALAN DENGAN PENDEKATAN BERORIENTASI OBJEK JAVA...Yunan Tanpa-i
Proposal ini membahas perancangan aplikasi pemesanan ojek online dengan pendekatan berorientasi objek. Aplikasi ini akan memiliki fitur login untuk admin dan pengguna, pemesanan ojek, pembayaran, serta notifikasi melalui SMS. Aplikasi ini diharapkan dapat memudahkan proses pemesanan ojek bagi pengguna.
Membuat Aplikasi Penghitung Luas Persegi Panjang Pada MATLABYunan Tanpa-i
Dokumen tersebut memberikan instruksi lengkap untuk membuat aplikasi penghitung luas persegi panjang menggunakan MATLAB. Langkah-langkahnya meliputi pembuatan figure baru, pengenalan tool, pengaturan properti komponen seperti edit text dan push button, penulisan kode untuk setiap callback, serta penjalana aplikasi.
The document discusses four famous explorers: Christopher Columbus, Juan Ponce de Leon, Jacques Cartier, and Christopher Newport. Columbus sailed for Spain in 1492 and was the first European to discover North America. He landed in the Bahamas and called the land the "New World." Juan Ponce de Leon sailed for Spain and was the first European to land in Florida, claiming the land for Spain. Jacques Cartier sailed for France and explored the St. Lawrence River Valley in Canada, giving France a North American land claim. Christopher Newport sailed for England, wanting to discover riches and find a western sea route to Asia. He helped establish the Jamestown colony in Virginia.
Pindaan Tarikh Cuti Peristiwa dan Cuti Berganti 2014Hootoh Tudia
Perubahan Tarikh Cuti Peristiwa dan Cuti Berganti Tahun 2014
http://www.hootoh.my/2014/01/perubahan-tarikh-cuti-peristiwa-cuti.html
Pindaan Takwim / Perubahan Tarikh Cuti Peristiwa dan Cuti Berganti Tahun 2014 oleh KPM Kementerian Pendidikan Malaysia melalui Surat Siaran bilangan 25 tahun 2013. Pembetulan dam Cadangan Tarikh Cuti Peristiwa Dan Cuti Berganti Sempena Perayaan Tahun Baru Cina, Hari Raya Aidil Fitri dan Hari Deepavali Tahun 2014
Presentation for the International Astronautical Conference in Beijing, China, September 2013. This paper describes the risks of solar maximum and space weather in general to space craft and terrestrial infrastructure. It is the final results of a research team project by students of the International Space University Space Studies Program 2013.
Download the full report and executive summary at http://isulibrary.isunet.edu/opac/index.php?lvl=notice_display&id=8859
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.
Pawan Kumar Relativistic jets in tidal disruption eventsBaurzhan Alzhanov
- Fast radio bursts (FRBs) are short, intense radio pulses that last about 1 millisecond. One FRB source produced multiple outbursts over several years.
- The leading model is that FRBs originate from young, highly magnetic neutron stars called magnetars. Charged particles are accelerated by magnetic reconnection, producing coherent curvature radiation observed as FRBs.
- FRBs provide insights into neutron star physics and energetic processes in magnetar magnetospheres. Predictions include observing FRB-like bursts at higher frequencies.
ICLR Friday Forum: Near-Earth Asteroid Impact (December 13, 2019)glennmcgillivray
The document discusses the near-Earth asteroid impact hazard. It provides information on the history of recognizing the impact threat, the sizes and frequencies of asteroid impacts, comparing the impact hazard to other dangers, and ways to address the impact hazard through asteroid detection and deflection. The key points are that major asteroid impacts capable of causing mass extinctions are rare but possible, smaller impacts pose a risk to local areas, and surveys are ongoing to detect potentially hazardous asteroids to provide warning and allow for mitigation if needed.
Small dust particles escaping from Pluto's moons Nix and Hydra could temporarily form a ring around Pluto due to impacts, but the solar radiation pressure would remove about half of 1 micrometer particles within a year by causing collisions with Pluto and its moons. Numerical simulations found that a tenuous ring with an optical depth of 6×10^-11 could be maintained by dust released from Nix and Hydra.
This document maps out the risks of asteroid impacts and strategies for asteroid defence. It divides asteroids into three size categories - those around 300m which could cause millions of deaths, those around 30km which could cause civilization collapse, and those over 10km which could cause human extinction. Observation is currently the best method for risk reduction, while large nuclear deflection risks creating more threats than benefits. The main uncertainty is whether Earth is currently experiencing an intense bombardment period due to a recent large comet breakup.
This document discusses meteor showers, asteroids, and comets. It notes that meteor showers occur yearly as Earth passes through debris from comets. It describes gaps in the distribution of asteroids called Kirkwood gaps, which are caused by resonances with Jupiter. It discusses evidence that asteroid families originated from collisions of larger parent bodies. The document also summarizes spacecraft visits to asteroids and comets, the different tails of comets, and forces like radiation pressure that affect small particles in the Solar System.
Jack Oughton - Astronomy, Eschatology and Apocalypse- Threats From Space.docJack Oughton
The document discusses various existential threats to humanity, including those of human origin like nuclear war and ozone depletion, and natural threats such as asteroid impacts, solar changes, gamma ray bursts, and the possibility of a hostile extraterrestrial civilization. It provides examples and potential solutions for each threat, noting that some threats like asteroid impacts and solar changes are inevitable but also occur over very long timescales, while others like nuclear war can be addressed through arms control and environmental protection. The document aims to raise awareness of existential risks while acknowledging that the likelihood of most scenarios is extremely low.
1) The document proposes using a spacecraft to deflect threatening asteroids via gravitational towing without physical attachment. The spacecraft would hover above the asteroid's surface, using outward-angled thrusters to pull it via gravity without disturbing the surface.
2) A 20-ton spacecraft with 1N of thrust could deflect a typical 200m asteroid over 20 years. For an asteroid like 99942 Apophis, a close Earth approach in 2029 could be influenced with just 0.1N of thrust for a month, preventing a possible later impact.
3) Gravitational towing is insensitive to the asteroid's properties and rotation, and allows controllable deflection as needed to protect Earth.
A gravitational tractor_for_towing_asteroidsSérgio Sacani
1) The document proposes using a "gravitational tractor" spacecraft that would hover above an asteroid's surface and tow it slowly using gravity as a towline, without needing physical attachment.
2) This deflection method is insensitive to the asteroid's properties and rotation, and the spacecraft need only maintain its position above while the asteroid rotates beneath.
3) For a typical 200m asteroid, simulations show a 20 ton gravitational tractor could deflect it from an Earth-impacting trajectory given a lead time of about 20 years using existing nuclear-electric propulsion.
X-Ray Luminous Supernovae: Threats to Terrestrial BiospheresSérgio Sacani
This document discusses the threat posed by X-ray luminous supernovae (SNe) to terrestrial biospheres. It analyzes observations of 31 X-ray luminous SNe from various telescopes. It finds that SNe showing strong circumstellar interaction, like Type IIn explosions, have significantly larger ranges of influence than previously thought, with lethal consequences up to around 50 parsecs away. The sustained high X-ray luminosity from these SNe leads to large doses of ionizing radiation over formidable distances. This poses a distinct threat to terrestrial biospheres and tightens the boundaries of the Galactic Habitable Zone. Follow-up X-ray observations of interacting SNe are needed to better understand the physical nature and
Near earth collisions are collisions that almost happen between space objects like asteroids or comets and Earth. The document discusses several major near earth collisions throughout history including the Chicxulub impactor asteroid that wiped out the dinosaurs, the proposed Shiva crater impact, and the 1908 Tunguska event explosion caused by a meteoroid or comet fragment. It also discusses scales for measuring asteroid impact risks like the Torino Scale and the need to develop programs to detect and potentially deflect asteroids on a collision course with Earth to avoid future mass extinctions.
Gravitational tractor for towing asteroidsCarlos Bella
1) A spacecraft could deflect an Earth-bound asteroid without docking to its surface by hovering near the asteroid and using its gravity as a towline.
2) This "gravitational tractor" method would impart small forces over time to alter the asteroid's trajectory and is insensitive to the asteroid's properties.
3) For example, a 20-tonne spacecraft could deflect a 200m asteroid within 20 years using its thrusters to hover near the asteroid and counteract its gravitational pull, imparting small changes to its velocity over time.
Earthquake Engineering 2012 Lecture 0103 Measures of Earthquakestharwat sakr
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The document discusses seismic waves generated by earthquakes and measures used to characterize earthquakes. There are three main types of seismic waves - P waves, S waves, and surface waves. P waves travel faster and can pass through solid rock, while S waves travel slower and cannot pass through liquids. Earthquake magnitude scales, peak ground accelerations, velocities and displacements are discussed as measures of earthquake size and intensity. The Modified Mercalli intensity scale from I to XII is explained which characterizes earthquake effects on people and structures.
The document discusses various cosmic events that pose dangers to life on Earth, including asteroids, comets, solar flares, supernovae, and gamma-ray bursts. These events have caused mass extinctions in the past and will continue to threaten life. Even relatively nearby occurrences of supernovae or gamma-ray bursts could damage the ozone layer and increase UV radiation, endangering life. Additionally, the Sun will gradually grow hotter over billions of years and eventually expand to engulf the Earth.
- Saturn's C ring was observed to have a subtle vertical corrugation extending across its entire width, revealed when the rings were illuminated edge-on.
- The corrugation has amplitudes between 2-20 meters and wavelengths of 30-80 km. Radial trends in the wavelength indicate it resulted from differential nodal regression after the ring plane became tilted in 1983.
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1) The universe is vast and dangerous, with our solar system and galaxy being relatively small parts of the larger universe.
2) Throughout Earth's history, there have been at least five mass extinctions caused by cosmic events like asteroids and comets. These events will continue to occur randomly in the future.
3) Other random cosmic events that can impact Earth include solar flares, supernovae, and gamma-ray bursts, with the latter having possibly contributed to a past mass extinction due to ozone depletion and increased UV radiation.
Similar to Kring background briefing about impact air blasts 18_feb2013 (20)
Kring background briefing about impact air blasts 18_feb2013
1. Background Briefing:
Impact Air Blasts Produced by Near-Earth Asteroids
Dr. David A. Kring
PI of the LPI-JSC NLSI Team
Detail from CLSE (Daniel D. Durda) image at
http://www.lpi.usra.edu/nlsi/training/illustrations/bombardment/
2. BRIEFING ABSTRACT
On Friday, 15 February
2013, a small asteroid
penetrated Earth’s
atmosphere and
catastrophically disrupted
over Russia, injuring people
and damaging buildings in
the area around Chelyabinsk
(55.2N, 61.4E). The injuries
and damage were caused by
shock waves and associated
air blasts. I have received a
lot of queries about these
types of events and have
collated some notes here to
address them.
Detail from CLSE (Daniel D. Durda) image at
http://www.lpi.usra.edu/nlsi/training/illustrations/bombardment/
3. CURRENT ESTIMATES OF EVENT PROPERTIES
Based on information released by Peter Brown and/or attributed to NASA
(as of 18 February 2013)
• Diameter of asteroid = 55 ft (17 m)
• Mass of asteroid = 10,000 tons
• Velocity of asteroid = 40,000 mph (17-18 km/s)
• Blast altitude = 15 to 20 km
• Equivalent energy of the explosive event = 500 kt of TNT
NOTE: Other sources have generated different estimates for the values above;
these values are preliminary and may change significantly.
The event was roughly an order of magnitude more energetic than the Sikhote-Alin
event of 1947 (~10 kt), but roughly an order of magnitude less energetic than the
Tunguska event of 1908 (~2-20 MT).
Caveats: Estimates of past events (even historical events like Tunguska) come with
lots of uncertainty.
That uncertainty underscores the need for modern, high-quality measurements of
impact-generated air blast events.
4. CURRENT ESTIMATES OF EVENT PROPERTIES
Based on information reported from Russia
(as of 18 February 2013)
• A portion of the catastrophically fragmented asteroid survives
• The meteoritic material resembles ordinary chondrites – which are from a class
of stony asteroids that contain a small amount of metal
Gold Basin event
Previously, the largest documented explosive
fragmentation of an ordinary chondritic
asteroid occurred over northwestern Arizona in
the Gold Basin area. That event involved an
~8 meter diameter asteroid with the kinetic
energy equivalent to 5 to 50 kt of TNT. Several
thousand relics of the asteroid were found in
the desert. See Kring et al. (2001) for details.
5. IMPACT VELOCITY
Typical asteroid velocity
Average impact
velocities of asteroids
hitting the Earth are
about 18 km/s.
The object that hit Earth
15 February 2013 event
15 February 2013 has an
estimated velocity of 17-
18 km/s, which is typical
of an asteroid and much
lower than that of typical
comets.
Thus, the velocity and
Illustration credit: CLSE (Shaner and Kring)
the recovery of ordinary
chondrites are
consistent.
6. COMPONENTS OF IMPACT AIR BLASTS
• Ballistic shock wave produced when an asteroid penetrates the atmosphere with
speed equal to or in excess of 11.2 km/s (≥25,000 mph)
• Explosive shock wave produced when the object catastrophically fragments in the
atmosphere or hits the surface to produce an impact crater
• The shock waves are accompanied by high-velocity air blasts
• Similar effects were measured around nuclear explosions test sites
7. CASE STUDY OF AN IMPACT AIR BLAST – BARRINGER (METEOR) CRATER
20-50 m iron asteroid Small cratering events
~50,000 yrs ago
Northern Arizona In small events, the fireball,
shock wave, and airblast are
the major environmental
effects.
The blast effect was
immediately lethal for human-
sized animals within the inner
6 km diameter circle.
Severe lung damage would
occur within the next 10-12
km diameter circle due to the
pressure pulse alone and
animals would be severely
injured and unlikely to survive.
See Kring (1997) and Grieve & Kring (2007) for details
8. CASE STUDY OF AN IMPACT AIR BLAST – BARRINGER (METEOR) CRATER
20-50 m iron asteroid Small cratering events
~50,000 yrs ago
Northern Arizona Winds would exceed 1500
km/hr within the inner circle
and still exceed 100 km/hr at
radial distances of 25 km (3rd
circle).
The outermost ~50 km circle
represents the outer limit of
severe to moderate damage
to trees and human-structures
of comparable strength.
See Kring (1997) and Grieve & Kring (2007) for details
9. CASE STUDY OF AN IMPACT AIR BLAST – BARRINGER (METEOR) CRATER
20-50 m iron asteroid Small cratering events
~50,000 yrs ago
Northern Arizona Such an event today could
decimate the population of an
urban area equivalent to the
size of Kansas City, U.S.A.
(population 425,000).
See Kring (1997) and Grieve & Kring (2007) for details 40 km circle corresponding to severe to
moderate damage.
10. CASE STUDY OF AN IMPACT AIR BLAST – MANICOUAGAN
Manicouagan
Larger impact cratering
events will produce air
blasts that affect a larger
area.
Manicouagan is a crater
with a diameter of ~100
km.
That impact air blast
affected a large fraction
of Canada.
Grieve and Kring (2007)
11. CASE STUDY OF AN IMPACT AIR BLAST – CHICXULUB CRATER
Dinosaur-killing event
At the extremely large
end of the spectrum is
the Chicxulub impact
event that caused a
mass extinction 65
million years ago.
The air blast produced
by that impact event
affected a large fraction
of North America.
The airblast is only one
See Emiliani et al. (1981) and Kring (2007) for details of many environmental
effects produced by this
size of impact event.
12. IMPACT AIR BLASTS OF DIFFERENT SIZES
Impact air blasts
The Chelyabinsk event is
at the extreme (small)
end of the types of
events that produce air
blasts.
Less frequent, larger
events can affect larger
areas.
As the world’s population
grows and occupies a
larger fraction of the
Earth’s surface, events
Modified after Figure 1.5 of Grieve and Kring (2007). Please see that paper or PPTx like Chelyabinsk will
notes (below) for a description of the uncertainties associated with the data plotted in the
diagram become more common.
13. SOURCES OF NEAR-EARTH ASTEROIDS
NEA source region
Near-Earth asteroids
come from the main
asteroid belt.
Their orbits, once nearly
circular, have been
perturbed by
gravitational processes
into elliptical orbits that
cross the orbit of Earth.
The pre-impact orbits of
previously fallen
meteorites illustrate this
point.
14. THE STRUCTURAL INTEGRITY OF NEAR-EARTH ASTEROIDS
The measured compressive strengths of ordinary chondrites may not be the best
measure of the structural integrity of near-Earth asteroids (see Kring et al. 1996
for evidence and discussion).
Instead, the strength of material may be limited to structural flaws (like fractures
or material contrasts) rather than the strength of individual clasts within them.
The fall phenomena associated with meteorites support the idea that structural
flaws limit the strength of near-Earth asteroid material. For example, fragmental
breccias preferentially fall apart in Earth’s atmosphere and produce meteorite
showers (Kring et al. 1999).
IMPORTANT : The Chelyabinsk event, if documented well, can be used to
determine the strength of the near-Earth asteroid, which is a fundamental
parameter needed for impact mitigation strategies.
15. REFERENCES
Emiliani, C., E. B. Kraus, and E. M. Shoemaker (1981) Sudden death at the end of
the Mesozoic. Earth and Planetary Science Letters 55, 317-334.
Grieve, R. A. F. and D. A. Kring (2007) The geologic record of destructive impact
events on Earth. In Comet/Asteriod Impacts and Human Society, P. Bobrowsky
and H. Rickman (eds.), Springer, Berlin, pp. 3-24.
Kring, D. A. (1997) Air blast produced by the Meteor Crater impact event and a
reconstruction of the affected environment. Meteoritics and Planetary Science 32,
517-530.
Kring, D. A. (2007) The Chicxulub impact event and its environmental
consequences at the Cretaceous-Tertiary boundary. Palaeogeography,
Palaeoclimatology, Palaeoecology 255, 4-21.
Kring, D. A., T. D. Swindle, D. T. Britt, and J. A. Grier (1996) Cat Mountain: A
meteoritic sample of an impact-melted asteroid regolith. Journal of Geophysical
Research 101, 29353-29371.
16. REFERENCES
Kring, D. A., D. H. Hill, J. D. Gleason, D. T. Britt, G. J. Consolmagno, M. Farmer, S.
Wilson, and R. Haag (1999) Portales Valley: A meteoritic sample of the brecciated
and metal-veined floor of an impact crater on an H-chondrite asteriod. Meteoritics
and Planetary Science 34, 663-669.
Kring, D. A., A. J. T. Jull, L. R. McHargue, P. A. Bland, D. H. Hill, and F. J. Berry
(2001) Gold Basin meteorite strewn field, Mojave Desert, northwestern Arizona:
Relic of a small late Pleistocene impact event. Meteoritics and Planetary Science
36, 1057-1066.
18. SIKHOTE-ALIN EVENT 1947
12 February 1947
Iron asteroid (type IIAB coarsest octahedrite)
46°9’36” N, 134°39’12” E
Sikhote-Alin Mountains, 25 miles from Novopoltavka, Maritime Province, Russia
A shower of fireballs produced 106 impact holes, the largest 28 meters in
diameter, over an area of 100 by 660 meters.
Over 27,000 kg of metal was found, the largest fragment weighing 300 kg.
Some of the metal have a characteristic shrapnel appearance.
19. TUNGUSKA EVENT 1908
30 June 1908
Believed to be a stony asteroid
60°54’ N, 101°57’ E
Krasnoyarskiy Kray, Evenki, Russia
An immense fireball and a catastrophic air blast flattened a large section of forest
and may have initiated short-lived fires.
Estimated mass of object is one thousand to one million tons.
Traces of surviving material from the impactor have been reported, but the object
was effectively obliterated in the explosion.
20. OTHER EVENTS FOR COMPARISON
Barringer Meteorite Crater (aka Meteor Crater), Arizona, ~50,000 years ago
• Estimated equivalent energy of cratering event ranges from ~2 to ~20 MT
• Iron asteroid
• Estimated diameter ranges from ~10 to ~50 m
Gold Basin, Arizona, 15-20 thousand years ago (Kring et al. 2001)
• Estimate equivalent energy of 5 to 50 kt of TNT
• ~8 meter diameter object
• Asteroid was composed of a breccia from the L-chondrite parent body
Asteroid 2008 TC3, Sudan, 2008 (Shaddad et al. 2010)
• Estimated equivalent energy of 1.2 kt of TNT
• Breccia
Indonesia 8 October 2009 (Silber et al. 2011)
• Estimated equivalent energy of atmospheric blast = 8 to 67 kt of TNT
• Favored best estimate of ~50 kt
• Type of asteroid unknown
21. OTHER EVENTS FOR COMPARISON
Sutter’s Mill, California, 22 April 2012 (Jenniskens et al. 2012)
• Estimated equivalent energy of 4.0 (-2.2/+3.4) kt of TNT
• High-speed entry velocity of 28.6 km/s
• ~2.5 m object
• Composed of regolith breccia from a carbonaceous chondrite parent body
22. ORDINARY CHONDRITE ASTEROID SAMPLES
We have over 50,000 samples of near-Earth asteroids in our collections
That includes a large number of samples from ordinary chondrite parent bodies.
There are at least three types of ordinary chondrite parent bodies:
• Type H – 17,747 meteorite samples
• Type L – 15,734 meteorite samples
• Type LL – 5,839 meteorite samples
• Totaling nearly 40,000 samples from ordinary chondrite parent bodies
• Per the Meteoritical Bulletin Database
23. CURRENT ESTIMATES OF EVENT PROPERTIES
Current estimates are based on infrasound data from the International Monitory
System (IMS) operated by the Comprehensive Nuclear-Test-Ban Treaty
Organization (CTBTO).
Estimates are also possible from satellite energy spectra, ground-based radar data,
and from the range of damage on the surface if the blast height is known.
The energy of the event and blast height are first-order products of the data
analysis. If a velocity is known, then the mass of the object can be inferred from the
kinetic energy (1/2 mv2). If a density is assumed, then the average size of the
object can be estimated. Passage through the atmosphere can decelerate the
object (hence affect velocity) and shed mass.
Any meteoritic material found can be used to refine the assumed density.
24. SMALL METEOR SEEN FROM THE INTERNATIONAL SPACE STATION (ISS)
Meteors
Most debris hitting the
Earth’s atmosphere is
too small to penetrate
and burns up without
causing any damage.
Astronaut ISS
photograph of meteor as
it passes through the
atmosphere.
The image was taken on
August 13, 2011, during
ISS028-E-024847 the Perseid Meteor
Shower of particles that
originate from Comet
Swift-Tuttle.
25. PENETRATING EARTH’S ATMOSPHERE
Meteoroids in Earth’s atmosphere
Krinov
The atmosphere is an effective filter
of impacting debris
Intermediate-size objects that are
not destroyed in the upper
atmosphere can fragment, producing
a shower of debris, or survive nearly
intact, producing a single meteorite.
Multiple fragmentation events are
possible.
Larger objects that are not
significantly decelerated and reach
the ground can produce
hypervelocity impact craters.
26. NOT ALL METEORITE SHOWERS PRODUCE DAMAGING AIRBLASTS
Portales Valley event
At~7:30 am on 13 June 1998, a
meteoroid entered Earth’s
atmosphere and fell near Portales,
New Mexico.
Witnesses reported hearing
detonations and seeing smoke trails
in the sky.
Before hitting the ground, the
meteoroid fragmented at least once,
producing a strewn field with a
length over 10 km.
See Kring et al. (1999) for details.
27. REFERENCES FOR ADDITIONAL SLIDES
Kring, D. A., D. H. Hill, J. D. Gleason, D. T. Britt, G. J. Consolmagno, M. Farmer, S.
Wilson, and R. Haag (1999) Portales Valley: A meteoritic sample of the brecciated
and metal-veined floor of an impact crater on an H-chondrite asteroid. Meteoritics
and Planetary Science 34, 663-669.
Krinov, E. L. (1966) Giant Meteorites. (Translated from Russian by J. S.
Romankiewicz.) Pergamon Press, New York, 397p.
Jenniskens, P. et al. (2012) Radar-enabled recovery of the Sutter’s Mill meteorite, a
carbonaceous chondrite regolith breccia. Science 338, 1583-1587.
Shaddad, M. H. et al. (2010) The recovery of asteroid 2008 TC3. Meteoritics and
Planetary Science 45, 1557-1589.
Silber, E. A., A. Le Pichon, and P. G. Brown (2011) Infrasonic detection of a near-
Earth asteroid object impact over Indonesia on 8 October 2009. Geophysical
Research Letters 38, L12201, doi:10.1029/2011GL047633.