The document discusses tectonic plates and natural hazards. It defines a natural hazard as a natural event that threatens lives and property. It describes tectonic hazards as caused by movements in the Earth's crust, such as earthquakes and volcanic eruptions. The document outlines the internal structure of the Earth and explains that tectonic plates consist of sections of the Earth's crust and upper mantle that move in relation to each other. There are different types of plate boundaries where plates diverge, converge or move past each other, resulting in geologic features like mid-ocean ridges, trenches and mountain ranges.
This document provides an introduction to metamorphism, including definitions, causes, limits, types, effects, and characteristics. Metamorphism is the change in form of pre-existing rocks due to increases in temperature, pressure, or both. The main types of metamorphism are contact/thermal, dynamic, and regional. Metamorphism results in recrystallization and realignment of minerals without melting, changing the rock's appearance, properties, and grade of alteration. Argillaceous sediments are most susceptible to metamorphic changes.
Divergent plate boundaries occur when tectonic plates pull apart from each other. Rising convection currents in the mantle push up on lithospheric plates, stretching and thinning the crust until it breaks along parallel faults tilted outward. This forms mid-ocean ridges or rift valleys on land. As the plates continue diverging, new crust is formed by magma rising through the cracks from the asthenosphere. Examples of divergent boundaries include the East Africa rift and Rio Grande rift.
This document summarizes the metamorphism of different rock types including ultramafic, mafic, pelitic, and calcareous rocks. Ultramafic rocks like peridotite and serpentinite can transform into serpentine, anthophyllite, olivine, and pyroxene minerals. Mafic rocks like basalt metamorphose into amphiboles and chlorite at low grades and amphibolite at intermediate grades, and granulite at highest grades. Pelitic rocks contain chlorite, muscovite, quartz and albite. Calcareous rocks like limestone coarsen but change little, while impure limestone forms diverse calcium-magnesium-sil
Geomagnetism and paleomagnetism are the two main divisions of magnetism in geophysics and geology. Geomagnetism deals with using magnetism to explore subsurface structures like minerals, basement rocks, and salt domes. Paleomagnetism studies the history of Earth's magnetic field and poles to understand rock histories and plate tectonics. Magnetism in rocks comes from ferromagnetic minerals like magnetite aligning their atomic magnets to retain magnetization even after the magnetic field is removed. This remanent magnetization can provide information about ancient field orientations and plate motions.
Modes of deformation of rocks presentationmadan lal
Rocks can deform in two main ways: brittle deformation and ductile deformation. Brittle deformation occurs near the surface where pressures and temperatures are low, causing rocks to fracture. Ductile deformation occurs at depth, where high pressures and temperatures cause permanent shape changes without fracturing. The type of deformation depends on factors like pressure, temperature, strain rate, and rock composition. Hard rocks under low pressure and temperature typically undergo brittle deformation, while soft rocks at depth experience ductile deformation.
1. The document discusses the different textures of igneous rocks, which refer to the size, shape, and arrangement of minerals within the rock.
2. Textures are classified based on crystallinity, granularity, mineral shape, and their mutual relationships. Some key textures mentioned include porphyritic, graphic, and ophitic.
3. Factors like cooling rate, mineral composition, and crystallization processes determine the unique textures that help identify different igneous rock types.
The document discusses plate tectonics and the evidence supporting continental drift. It describes how Wegener first proposed the hypothesis of continental drift in 1912 based on observations that the continents seemed to fit together. The document outlines several pieces of evidence that supported Wegener's hypothesis, including matching coastlines, shared fossil distributions, and geological and climatic similarities between separated continents. It then describes how the theory of seafloor spreading provided further evidence when studies in the 1940s and 1950s showed the ocean floor was younger than the continents and spreading occurred at mid-ocean ridges. Paleomagnetic data from the seafloor also supported seafloor spreading and continental drift. Today the theory of plate tectonics unifies
The document summarizes Earth's internal structure and tectonic plate theory. It describes three main layers - the crust, mantle, and core. The crust and upper mantle make up the lithosphere which is divided into separate tectonic plates that move over the asthenosphere due to convection currents in the mantle. Plate boundaries occur where plates meet and cause volcanoes, earthquakes, and mountains through divergent, convergent and transform interactions.
This document provides an introduction to metamorphism, including definitions, causes, limits, types, effects, and characteristics. Metamorphism is the change in form of pre-existing rocks due to increases in temperature, pressure, or both. The main types of metamorphism are contact/thermal, dynamic, and regional. Metamorphism results in recrystallization and realignment of minerals without melting, changing the rock's appearance, properties, and grade of alteration. Argillaceous sediments are most susceptible to metamorphic changes.
Divergent plate boundaries occur when tectonic plates pull apart from each other. Rising convection currents in the mantle push up on lithospheric plates, stretching and thinning the crust until it breaks along parallel faults tilted outward. This forms mid-ocean ridges or rift valleys on land. As the plates continue diverging, new crust is formed by magma rising through the cracks from the asthenosphere. Examples of divergent boundaries include the East Africa rift and Rio Grande rift.
This document summarizes the metamorphism of different rock types including ultramafic, mafic, pelitic, and calcareous rocks. Ultramafic rocks like peridotite and serpentinite can transform into serpentine, anthophyllite, olivine, and pyroxene minerals. Mafic rocks like basalt metamorphose into amphiboles and chlorite at low grades and amphibolite at intermediate grades, and granulite at highest grades. Pelitic rocks contain chlorite, muscovite, quartz and albite. Calcareous rocks like limestone coarsen but change little, while impure limestone forms diverse calcium-magnesium-sil
Geomagnetism and paleomagnetism are the two main divisions of magnetism in geophysics and geology. Geomagnetism deals with using magnetism to explore subsurface structures like minerals, basement rocks, and salt domes. Paleomagnetism studies the history of Earth's magnetic field and poles to understand rock histories and plate tectonics. Magnetism in rocks comes from ferromagnetic minerals like magnetite aligning their atomic magnets to retain magnetization even after the magnetic field is removed. This remanent magnetization can provide information about ancient field orientations and plate motions.
Modes of deformation of rocks presentationmadan lal
Rocks can deform in two main ways: brittle deformation and ductile deformation. Brittle deformation occurs near the surface where pressures and temperatures are low, causing rocks to fracture. Ductile deformation occurs at depth, where high pressures and temperatures cause permanent shape changes without fracturing. The type of deformation depends on factors like pressure, temperature, strain rate, and rock composition. Hard rocks under low pressure and temperature typically undergo brittle deformation, while soft rocks at depth experience ductile deformation.
1. The document discusses the different textures of igneous rocks, which refer to the size, shape, and arrangement of minerals within the rock.
2. Textures are classified based on crystallinity, granularity, mineral shape, and their mutual relationships. Some key textures mentioned include porphyritic, graphic, and ophitic.
3. Factors like cooling rate, mineral composition, and crystallization processes determine the unique textures that help identify different igneous rock types.
The document discusses plate tectonics and the evidence supporting continental drift. It describes how Wegener first proposed the hypothesis of continental drift in 1912 based on observations that the continents seemed to fit together. The document outlines several pieces of evidence that supported Wegener's hypothesis, including matching coastlines, shared fossil distributions, and geological and climatic similarities between separated continents. It then describes how the theory of seafloor spreading provided further evidence when studies in the 1940s and 1950s showed the ocean floor was younger than the continents and spreading occurred at mid-ocean ridges. Paleomagnetic data from the seafloor also supported seafloor spreading and continental drift. Today the theory of plate tectonics unifies
The document summarizes Earth's internal structure and tectonic plate theory. It describes three main layers - the crust, mantle, and core. The crust and upper mantle make up the lithosphere which is divided into separate tectonic plates that move over the asthenosphere due to convection currents in the mantle. Plate boundaries occur where plates meet and cause volcanoes, earthquakes, and mountains through divergent, convergent and transform interactions.
Mantle melting occurs when heat and pressure cause partial melting of the mantle, producing basaltic magma. Basalt is the most common volcanic rock on Earth and can be further differentiated to form other igneous rock types. Evidence for the composition and processes of the mantle comes from ophiolites, dredged samples from ocean floors, nodules contained in basalts, and xenoliths brought up from deep in the mantle via kimberlite eruptions. Together this evidence indicates that the upper mantle is composed predominantly of the minerals olivine, orthopyroxene, and clinopyroxene which make up the rocks dunite, harzburgite, and lherzol
A fabric describes the spatial and geometric relationships that make up a rock at the microscopic to centimeter scale. It includes planar structures like bedding and cleavage, as well as the preferred orientation of minerals. There are different types of fabric including linear fabric formed by elongate minerals, planar fabric formed by platy minerals, and random fabric with no orientation. Foliation specifically refers to any planar arrangement of minerals or structures in a rock. Foliation can be primary, forming during rock formation, or secondary, resulting from deformation. Common types of secondary foliation include cleavage, schistosity, and mylonitic foliation. Lineation describes a preferred linear orientation of features in a rock, often related to deformation processes like intersection of planar
Rocks are divided into three major groups: igneous, sedimentary, and metamorphic. Igneous rocks form from the cooling and solidification of magma either underground to form intrusive rocks or on the surface to form extrusive rocks. The texture and structure of igneous rocks depends on factors like the cooling rate, mineral composition, and gas content of the magma. Common igneous rock features include phenocrysts, vesicles, xenoliths, columnar joints, and sills/dikes.
1) The Mid-Ocean Ridge system circles the Earth along the ocean floor and is over 56,000 km long. It forms at divergent plate boundaries where new oceanic crust is continually being formed.
2) Scientists use sonar to map the ocean floor and study its features like the Mid-Ocean Ridge. Sonar bounces sound waves off underwater objects to image the seafloor.
3) Evidence like magnetic stripes in ocean crust and samples dug from the seafloor support the theory of sea floor spreading, where new crust forms at ridges and spreads out over time.
1) Oceanic plates diverge from each other at mid-ocean ridges. Magma rises from the mantle to fill the gap between separating plates, cooling to form new ocean crust. The youngest ocean crust is closest to the ridge.
2) Continental plates can diverge, resulting in rift valleys like East Africa's Great Rift Valley. The stretched crust fractures and the land between sinks, forming a low-lying valley. Continental divergence can also form seas like the Red Sea.
3) Faulting occurs as the crust fractures along tensional forces during plate divergence. Rift valleys form along fault lines, and block mountains are uplifted crustal blocks surrounded by sinking land.
Metamorphic rocks form from older igneous, sedimentary, or metamorphic rocks through heat and pressure, such as from earthquakes and volcanism. This heat and pressure can flatten mineral grains without melting the rock or change one rock type into another metamorphic type over time. Metamorphic rocks are classified based on whether their mineral grains form layers (foliated) or not (nonfoliated), and examples include slate, gneiss, and marble. These rocks have various uses including floors, buildings, statues, and tombstones.
This document summarizes a presentation on stress and its types. It defines stress as a force acting on an area. It describes three main types of stress: compressional stress which causes rocks to push together and can result in reverse faults; tensional stress which pulls rocks apart and can cause normal faults; and shear stress which acts in opposite directions parallel to each other and can produce strike-slip faults. It concludes that plate tectonics movements generate stress at plate boundaries through compression at converging boundaries and tension at diverging boundaries.
This document discusses metamorphism and metamorphic rocks. It defines metamorphism as a change in shape of pre-existing rocks due to heat and pressure below the surface. It describes different types of metamorphism including contact, dynamic, and regional metamorphism. It also defines foliated and non-foliated metamorphic rocks, providing examples like slate, schist, and gneiss. The document aims to explain metamorphic concepts and rock types to students.
The document discusses the four spheres of the Earth - atmosphere, hydrosphere, lithosphere, and biosphere. It then describes the layers that make up Earth's interior - crust, mantle, outer core, and inner core. The rest of the document discusses plate tectonic theory, the three types of plate boundaries and movements (divergent, convergent, transform), associated volcanic and earthquake activity, and the impacts of earthquakes and volcanoes.
This document discusses structural geography and stratigraphy. It defines structural geography as the study of dip, strike, outcrops, inliers, outliers, discontinuities, folds, faults, joints and unconformities in rock structures. Stratigraphy is divided into lithostratigraphy, which studies rock layers based on lithology, and biostratigraphy, which uses fossil assemblages to correlate rock ages. The principles of stratigraphy include original horizontality, superposition, lateral continuity, cross-cutting relationships, inclusions, faunal succession, and uniformitarianism. Types of stratigraphy are lithostratigraphy, chronostratigraphy, biostratigraphy, magnetostratigraphy, allostratigraphy, geochron
This document defines and classifies different types of foliation in metamorphic rocks. It begins by defining foliation as a planar or curvi-planar fabric formed in metamorphic rocks. Foliations are classified genetically as primary, secondary, or inherited, and morphologically as spaced, continuous, or disjunctive. Key types of secondary foliation include cleavage, schistosity, slip cleavage, and shear cleavage. Foliations provide important information about the tectonic and metamorphic evolution of an area and help determine the geometry of folding. Different foliation types reflect variations in lithology and temperature during metamorphism and deformation.
The document summarizes key concepts about earthquakes and Earth's interior structure from a textbook chapter. It describes what causes earthquakes, how they are measured, the different types of seismic waves, and the destructive effects of earthquakes. It also outlines Earth's layered structure, including the crust, mantle, outer core, and inner core defined by their composition and physical properties. Seismic data has helped scientists discover details about Earth's layered interior and composition.
The document discusses the composition and structure of the Earth's interior based on seismic data and studies of meteorites and mantle rocks. It can be summarized as follows:
1) The Earth is composed of an iron-nickel core surrounded by a silicate mantle and crust. The density increases towards the center.
2) The continental crust averages 30 km thick and has a composition ranging from granodiorite to diorite. The oceanic crust is 6-7 km thick and composed of three layers: an upper volcanic layer, a middle intrusive gabbro layer, and a lower ultramafic layer.
3) The mantle extends from the Moho to the core-mantle boundary. Se
This document discusses metamorphism and metamorphic rocks. Metamorphic rocks form from existing igneous, sedimentary, or other metamorphic rocks through heat, pressure, and chemically reactive fluids. Metamorphism progresses incrementally and involves the growth of new minerals and deformation of existing ones. Metamorphism occurs in various settings like contact, regional, and burial metamorphism. Factors like heat, pressure, and fluids drive changes in mineralogy and texture. Metamorphic grade is indicated by index minerals and results in foliated and non-foliated rock types.
The Earth is an unusual planet by having bimodal topography that reflects the two distinct types of crust.
Crust is outer part of the Earth and compositionally is consist tow types, continental and oceanic crust.
The oceanic crust is thin (~ 7 km ), and composed from denser rocks such as basalt , younger.
Whereas the continental crust is thick (~ 40 Km), and composed of highly diverse lithologies, and contains the oldest rocks.
The document discusses plate tectonics and the theory that Earth's outer shell is divided into plates that glide over the mantle. It describes three main types of plate boundaries: convergent boundaries where plates collide, divergent boundaries where plates move apart, and transform boundaries where plates slide past each other. Convergent boundaries can involve subduction zones and result in mountain building. Divergent boundaries create new crust and can form undersea ridges or split continents. Transform boundaries cause earthquakes as stress builds up between sliding plates.
The document discusses metamorphic petrology, including the processes, conditions, and products of metamorphism. It defines metamorphism as the mineralogical and textural changes rocks undergo in the solid state due to changes in physical and chemical conditions. Metamorphic conditions include temperature, pressure, and fluid compositions. The document also describes the goals of metamorphic petrology in determining the setting, protolith, grade, and conditions of metamorphism through mineral assemblages and textures. Finally, it discusses metamorphic facies and indexes that help characterize metamorphic grade based on characteristic mineral assemblages.
Tectonic plates move due to convection currents in the mantle and slab pull forces. There are different types of plate boundaries including divergent where plates move apart, convergent where they move together, and transform where they slide past each other. These boundaries result in different landforms through geological processes. Divergent boundaries form rift valleys and volcanoes, convergent boundaries form fold mountains, volcanoes and trenches, and transform boundaries cause earthquakes. Natural hazards occur near plate boundaries like earthquakes, volcanic eruptions and tsunamis.
This document discusses natural hazards caused by tectonic and climate-related events. It provides details on the internal structure of the Earth, including the crust and mantle. It then focuses on plate tectonics, explaining the three main types of plate boundaries and associated landforms. Specific examples are given for each plate boundary type. The document also addresses causes of earthquakes and their impacts, as well as types and characteristics of volcanoes.
Mantle melting occurs when heat and pressure cause partial melting of the mantle, producing basaltic magma. Basalt is the most common volcanic rock on Earth and can be further differentiated to form other igneous rock types. Evidence for the composition and processes of the mantle comes from ophiolites, dredged samples from ocean floors, nodules contained in basalts, and xenoliths brought up from deep in the mantle via kimberlite eruptions. Together this evidence indicates that the upper mantle is composed predominantly of the minerals olivine, orthopyroxene, and clinopyroxene which make up the rocks dunite, harzburgite, and lherzol
A fabric describes the spatial and geometric relationships that make up a rock at the microscopic to centimeter scale. It includes planar structures like bedding and cleavage, as well as the preferred orientation of minerals. There are different types of fabric including linear fabric formed by elongate minerals, planar fabric formed by platy minerals, and random fabric with no orientation. Foliation specifically refers to any planar arrangement of minerals or structures in a rock. Foliation can be primary, forming during rock formation, or secondary, resulting from deformation. Common types of secondary foliation include cleavage, schistosity, and mylonitic foliation. Lineation describes a preferred linear orientation of features in a rock, often related to deformation processes like intersection of planar
Rocks are divided into three major groups: igneous, sedimentary, and metamorphic. Igneous rocks form from the cooling and solidification of magma either underground to form intrusive rocks or on the surface to form extrusive rocks. The texture and structure of igneous rocks depends on factors like the cooling rate, mineral composition, and gas content of the magma. Common igneous rock features include phenocrysts, vesicles, xenoliths, columnar joints, and sills/dikes.
1) The Mid-Ocean Ridge system circles the Earth along the ocean floor and is over 56,000 km long. It forms at divergent plate boundaries where new oceanic crust is continually being formed.
2) Scientists use sonar to map the ocean floor and study its features like the Mid-Ocean Ridge. Sonar bounces sound waves off underwater objects to image the seafloor.
3) Evidence like magnetic stripes in ocean crust and samples dug from the seafloor support the theory of sea floor spreading, where new crust forms at ridges and spreads out over time.
1) Oceanic plates diverge from each other at mid-ocean ridges. Magma rises from the mantle to fill the gap between separating plates, cooling to form new ocean crust. The youngest ocean crust is closest to the ridge.
2) Continental plates can diverge, resulting in rift valleys like East Africa's Great Rift Valley. The stretched crust fractures and the land between sinks, forming a low-lying valley. Continental divergence can also form seas like the Red Sea.
3) Faulting occurs as the crust fractures along tensional forces during plate divergence. Rift valleys form along fault lines, and block mountains are uplifted crustal blocks surrounded by sinking land.
Metamorphic rocks form from older igneous, sedimentary, or metamorphic rocks through heat and pressure, such as from earthquakes and volcanism. This heat and pressure can flatten mineral grains without melting the rock or change one rock type into another metamorphic type over time. Metamorphic rocks are classified based on whether their mineral grains form layers (foliated) or not (nonfoliated), and examples include slate, gneiss, and marble. These rocks have various uses including floors, buildings, statues, and tombstones.
This document summarizes a presentation on stress and its types. It defines stress as a force acting on an area. It describes three main types of stress: compressional stress which causes rocks to push together and can result in reverse faults; tensional stress which pulls rocks apart and can cause normal faults; and shear stress which acts in opposite directions parallel to each other and can produce strike-slip faults. It concludes that plate tectonics movements generate stress at plate boundaries through compression at converging boundaries and tension at diverging boundaries.
This document discusses metamorphism and metamorphic rocks. It defines metamorphism as a change in shape of pre-existing rocks due to heat and pressure below the surface. It describes different types of metamorphism including contact, dynamic, and regional metamorphism. It also defines foliated and non-foliated metamorphic rocks, providing examples like slate, schist, and gneiss. The document aims to explain metamorphic concepts and rock types to students.
The document discusses the four spheres of the Earth - atmosphere, hydrosphere, lithosphere, and biosphere. It then describes the layers that make up Earth's interior - crust, mantle, outer core, and inner core. The rest of the document discusses plate tectonic theory, the three types of plate boundaries and movements (divergent, convergent, transform), associated volcanic and earthquake activity, and the impacts of earthquakes and volcanoes.
This document discusses structural geography and stratigraphy. It defines structural geography as the study of dip, strike, outcrops, inliers, outliers, discontinuities, folds, faults, joints and unconformities in rock structures. Stratigraphy is divided into lithostratigraphy, which studies rock layers based on lithology, and biostratigraphy, which uses fossil assemblages to correlate rock ages. The principles of stratigraphy include original horizontality, superposition, lateral continuity, cross-cutting relationships, inclusions, faunal succession, and uniformitarianism. Types of stratigraphy are lithostratigraphy, chronostratigraphy, biostratigraphy, magnetostratigraphy, allostratigraphy, geochron
This document defines and classifies different types of foliation in metamorphic rocks. It begins by defining foliation as a planar or curvi-planar fabric formed in metamorphic rocks. Foliations are classified genetically as primary, secondary, or inherited, and morphologically as spaced, continuous, or disjunctive. Key types of secondary foliation include cleavage, schistosity, slip cleavage, and shear cleavage. Foliations provide important information about the tectonic and metamorphic evolution of an area and help determine the geometry of folding. Different foliation types reflect variations in lithology and temperature during metamorphism and deformation.
The document summarizes key concepts about earthquakes and Earth's interior structure from a textbook chapter. It describes what causes earthquakes, how they are measured, the different types of seismic waves, and the destructive effects of earthquakes. It also outlines Earth's layered structure, including the crust, mantle, outer core, and inner core defined by their composition and physical properties. Seismic data has helped scientists discover details about Earth's layered interior and composition.
The document discusses the composition and structure of the Earth's interior based on seismic data and studies of meteorites and mantle rocks. It can be summarized as follows:
1) The Earth is composed of an iron-nickel core surrounded by a silicate mantle and crust. The density increases towards the center.
2) The continental crust averages 30 km thick and has a composition ranging from granodiorite to diorite. The oceanic crust is 6-7 km thick and composed of three layers: an upper volcanic layer, a middle intrusive gabbro layer, and a lower ultramafic layer.
3) The mantle extends from the Moho to the core-mantle boundary. Se
This document discusses metamorphism and metamorphic rocks. Metamorphic rocks form from existing igneous, sedimentary, or other metamorphic rocks through heat, pressure, and chemically reactive fluids. Metamorphism progresses incrementally and involves the growth of new minerals and deformation of existing ones. Metamorphism occurs in various settings like contact, regional, and burial metamorphism. Factors like heat, pressure, and fluids drive changes in mineralogy and texture. Metamorphic grade is indicated by index minerals and results in foliated and non-foliated rock types.
The Earth is an unusual planet by having bimodal topography that reflects the two distinct types of crust.
Crust is outer part of the Earth and compositionally is consist tow types, continental and oceanic crust.
The oceanic crust is thin (~ 7 km ), and composed from denser rocks such as basalt , younger.
Whereas the continental crust is thick (~ 40 Km), and composed of highly diverse lithologies, and contains the oldest rocks.
The document discusses plate tectonics and the theory that Earth's outer shell is divided into plates that glide over the mantle. It describes three main types of plate boundaries: convergent boundaries where plates collide, divergent boundaries where plates move apart, and transform boundaries where plates slide past each other. Convergent boundaries can involve subduction zones and result in mountain building. Divergent boundaries create new crust and can form undersea ridges or split continents. Transform boundaries cause earthquakes as stress builds up between sliding plates.
The document discusses metamorphic petrology, including the processes, conditions, and products of metamorphism. It defines metamorphism as the mineralogical and textural changes rocks undergo in the solid state due to changes in physical and chemical conditions. Metamorphic conditions include temperature, pressure, and fluid compositions. The document also describes the goals of metamorphic petrology in determining the setting, protolith, grade, and conditions of metamorphism through mineral assemblages and textures. Finally, it discusses metamorphic facies and indexes that help characterize metamorphic grade based on characteristic mineral assemblages.
Tectonic plates move due to convection currents in the mantle and slab pull forces. There are different types of plate boundaries including divergent where plates move apart, convergent where they move together, and transform where they slide past each other. These boundaries result in different landforms through geological processes. Divergent boundaries form rift valleys and volcanoes, convergent boundaries form fold mountains, volcanoes and trenches, and transform boundaries cause earthquakes. Natural hazards occur near plate boundaries like earthquakes, volcanic eruptions and tsunamis.
This document discusses natural hazards caused by tectonic and climate-related events. It provides details on the internal structure of the Earth, including the crust and mantle. It then focuses on plate tectonics, explaining the three main types of plate boundaries and associated landforms. Specific examples are given for each plate boundary type. The document also addresses causes of earthquakes and their impacts, as well as types and characteristics of volcanoes.
This is the summary on gateway 1 on plate tectonic. It discusses about the following:
1) Characteristics of the different structure of the earth.
2) The mechanism leading to plate movement
3) Landforms associated to the different plate movement.
The document discusses tectonic hazards from living in areas prone to natural disasters. It describes a deadly 2010 eruption of Mount Merapi in Indonesia that killed over 350 people and forced 300,000 from their homes, despite warnings. Some remained to care for cattle. It also discusses over 600,000 people living near the dangerous Mount Vesuvius volcano in Italy, which last erupted catastrophically in 79 CE. The chapter explores why some areas are more prone to tectonic hazards, landforms at plate boundaries, and earthquake preparedness and response.
This document provides information about natural hazards caused by tectonic plate movements. It discusses the three main types of plate boundaries: divergent where plates move apart, convergent where they move together, and transform where they move past each other. At divergent boundaries, mid-ocean ridges and volcanic islands form through sea floor spreading. Rift valleys and block mountains form when continents split apart. At convergent boundaries, denser plates subduct under lighter ones, creating ocean trenches, volcanic island arcs, and fold mountains through compression. Transform boundaries cause earthquakes along tear faults as plates grind past each other.
The Earth is composed of layers including the crust divided into tectonic plates that move over time. There are three types of plate boundaries - divergent where plates move apart, convergent where they collide, and transform where they slide past each other. Plate interactions cause volcanic activity and earthquakes, most commonly at plate margins.
The document discusses the internal structure and composition of the Earth. It describes how temperature, pressure, and density increase towards the core. The Earth has a solid inner core made of iron and nickel, a liquid outer core also made of iron and nickel, a thick mantle made of silicate rocks, and a thin crust on top. Seismic data is used to determine this internal structure.
Geologists have learned about Earth's interior through examining rock samples and studying seismic waves. Temperature and pressure both increase with depth inside Earth. The crust and mantle are divided into layers with different physical properties. Convection currents in the mantle are driven by heat from the core and cause the tectonic plates to slowly move over time. The theory of plate tectonics explains how new crust forms at mid-ocean ridges and old crust is recycled into the mantle at subduction zones, causing the plates to drift apart or collide together over hundreds of millions of years.
This document discusses elements of seismology and earthquake engineering. It covers topics such as causes of earthquakes including plate tectonic theory, elastic rebound theory, types of seismic waves, measurement of earthquakes through seismographs, magnitude and intensity scales, and characteristics of strong ground motion. Key concepts are the different types of plate boundaries that can cause earthquakes, as well as the different types of seismic waves like P, S, love, and rayleigh waves that radiate from earthquake sources.
The Earth's crust is divided into 12 major tectonic plates that are constantly moving due to convection currents in the underlying mantle. There are three main types of plate boundaries - divergent where plates move apart, convergent where they collide, and transform where they slide past each other. Plate tectonics explains global patterns of volcanic and earthquake activity which predominantly occur at plate boundaries as the plates interact, collide and subduct.
The document summarizes the theory of plate tectonics. It explains that the Earth's crust is broken into plates that are constantly moving due to convection currents in the mantle. There are three main types of plate boundaries: divergent where plates pull apart and new crust is formed; convergent where plates crash together and can cause volcanic activity and mountain building; and transform where plates slide past each other and can cause earthquakes. The theory integrated the earlier concepts of continental drift, which proposed the slow drifting of continents, and seafloor spreading, which showed new crust was forming under the oceans. Together, these theories explained how plate tectonics shapes the Earth's surface over millions of years through volcanic and seismic activity
The document summarizes the theory of plate tectonics. It explains that the Earth's crust is broken into plates that are constantly moving due to convection currents in the mantle. There are three main types of plate boundaries: divergent where plates pull apart and new crust is formed, convergent where plates crash together forming mountains or one plate slides under the other, and transform where plates slide past each other causing earthquakes. The theory developed from the theories of continental drift proposing the splitting of Pangaea and seafloor spreading explaining the patterns of aging rocks in the oceans. Together these theories explained how plate motions and interactions at their boundaries shape the Earth's surface over millions of years.
The document summarizes the theory of plate tectonics. It explains that the Earth's crust is broken into plates that move due to convection currents in the mantle. There are three types of plate boundaries - divergent where plates move apart and new crust is formed, convergent where plates collide and one slides under the other, and transform where plates slide past each other. The constant movement of plates is what creates geological features like mountains and ocean trenches.
Chapter 1 living with tectonic hazards tr copyivisdude82
This document discusses tectonic plates and hazards. It begins by defining a natural hazard and describing the internal structure of the Earth. Tectonic plates consist of oceanic and continental crust and move due to convection currents in the mantle. There are three types of plate boundaries: divergent, convergent, and transform. Divergent boundaries form mid-ocean ridges and rift valleys, convergent boundaries result in ocean trenches, volcanic islands, and mountain ranges, and transform boundaries cause earthquakes along strike-slip faults. Specific examples of each boundary type are highlighted, such as sea-floor spreading at oceanic divergent boundaries and the Himalayas forming from the Indian and Eurasian plate collision.
1. There are three main types of plate boundaries: divergent boundaries where plates move apart, convergent boundaries where plates move together, and transform boundaries where plates slide past one another.
2. At divergent boundaries, new oceanic crust is formed at mid-ocean ridges. This results in features like rift valleys on land and undersea volcanoes at sea. Convergent boundaries result in ocean trenches from subducting plates and volcanic island arcs. Continental collisions yield fold mountains from compressed crust.
3. Key landforms and phenomena associated with plate tectonics include mid-ocean ridges, rift valleys and block mountains, ocean trenches, volcanic island arcs, and fold mountains. Earthquakes also
WHAT IS A PLATE? MAJOR PLATES. Types of Earth’s Crust. Plate BoundaryUday Kumar Shil
The document discusses plate tectonics and the key concepts of plate tectonic theory. It describes how the lithosphere is broken into large plates that move over Earth's surface, driven by convection currents in the underlying mantle. It outlines the three main types of plate boundaries - divergent boundaries where new crust forms, transform boundaries where plates slide past each other, and convergent boundaries where plates collide and one slides under the other. It also discusses the evidence that supported the development of plate tectonic theory, such as seafloor spreading and magnetic reversals recorded in oceanic crust.
1) The Earth is made up of three main layers - the core, mantle, and crust. The crust is divided into tectonic plates that slowly move around the globe.
2) There are three types of plate boundaries - divergent where plates move apart, convergent where they collide, and transform where they slide past each other. Each type forms different geological features.
3) Volcanoes and earthquakes tend to occur along plate boundaries as a result of the movement and interactions between plates. Major volcanic and seismic activity is concentrated in places like the Pacific Ring of Fire.
Similar to Chapter 1 gateway 123 combined students (20)
This document discusses key geographical skills including topographical map reading, geographical data techniques, and conducting geographical investigations. It covers topics such as reading grid references, measuring distances on maps, interpreting map symbols and scales, describing landforms and relief, settlement patterns, and using compasses to find bearings. It also discusses creating and interpreting various types of graphs to display geographical data, such as line graphs, bar graphs, pie charts, scatterplots, climographs, and histograms. Finally, it discusses the phases of conducting geographical fieldwork and how to develop hypotheses or guiding questions.
This document discusses various weather elements such as temperature, rainfall, relative humidity, air pressure, and wind. It defines these elements and describes the instruments used to measure them. For temperature, it explains how factors such as latitude, altitude, distance from the sea, and cloud cover can influence temperatures in different locations. It also provides examples to illustrate these effects. For rainfall, it distinguishes between convective and relief rainfall and includes diagrams to explain their formation. The document is intended to build understanding of key weather concepts.
Natural hazards include tectonic hazards like volcanic eruptions and earthquakes, as well as climate-related hazards such as typhoons and floods. The internal structure of Earth includes the crust, mantle, and core. The crust varies in thickness and composition depending on whether it is oceanic crust or continental crust. Oceanic crust is thinner and denser, while continental crust is thicker and less dense. Tectonic plates move due to convection currents in the mantle, with plates separating at mid-ocean ridges and coming together at subduction zones.
The document discusses different types of tourism:
1) Honeypot tourism refers to popular attractions that attract large numbers of tourists, such as the Taj Mahal and Colosseum.
2) MICE tourism focuses on destinations that provide amenities for meetings, incentives, conferences, and exhibitions, like convention centers in Singapore.
3) Medical tourism has risen with destinations offering good medical facilities and procedures, like cosmetic surgery in South Korea.
1. The document outlines the steps of a geographic inquiry (GI) including forming a hypothesis, collecting and analyzing data, and presenting conclusions.
2. It discusses methods for collecting data through surveys, questionnaires, and observation and includes tips for effective survey design and administration.
3. Finally, it addresses evaluating the reliability and limitations of the collected data, identifying trends or anomalies, and assessing whether the hypothesis is supported.
1. The document outlines the steps of conducting a geographic inquiry (GI) including forming a hypothesis, collecting and analyzing data, and presenting a conclusion.
2. It discusses methods for collecting data through surveys, questionnaires, and observation and includes tips for effective survey design and administration.
3. The document also presents different sampling methods and examples of ways to organize and present collected data including tables, flow maps, and desire line maps.
This chapter discusses key geographical skills like map reading, interpreting data representations, and conducting fieldwork investigations. It covers topics such as reading grid references, compass directions, scales, measuring distances, interpreting reliefs and landforms on maps, and analyzing photographs and satellite images. Various types of graphs like line graphs, bar graphs, pie charts, and climographs are introduced to represent geographical data. The three phases of fieldwork - pre-fieldwork, during fieldwork, and post-fieldwork - are also outlined.
This document discusses weather, climate, and climate change. It begins by defining weather and climate, and describes the key elements of weather including temperature, relative humidity, clouds, rainfall, air pressure, and wind. It then explains the major climate types and their locations: equatorial, monsoon, and cool temperate marine west coast climates. The document goes on to discuss evidence that the global climate has changed in recent decades due to both natural and human factors like the greenhouse effect. It may lead to more extreme weather and affect people. Responses to address climate change are also mentioned.
The document discusses various types and concepts related to tourism. It begins by defining tourism and a tourist. It then outlines different types of tourism such as honeypot tourism, MICE tourism, medical tourism, and religious tourism. It also discusses factors that influence the growth of global tourism like increasing disposable income and leisure time as well as investments in destination infrastructure. The document notes some impacts of tourism including positive economic benefits but also potential negative socio-cultural and environmental impacts. It identifies key stakeholders involved in tourism development and discusses the importance of sustainable tourism.
The document discusses the strengths and limitations of locals and tourists in protecting tourist areas. For locals, community-based tourism provides jobs and business opportunities, as seen in a village in Java. However, locals may lack skilled labor to manage tourism's impacts. For tourists, their spending supports conservation, but they can damage areas through littering and vandalism. Overall, locals play a largely effective role, but would benefit from training to improve conservation skills.
This document provides an overview of topics covered in an elective geography exam, including:
1. Forming and testing hypotheses about tourism relationships.
2. Designing surveys, identifying limitations, and making improvements to data collection methods.
3. Representing and analyzing data using graphs, charts, and maps to identify trends in tourism numbers and flows over different time periods and locations.
An earthquake is caused by the sudden release of energy along fault lines, generating seismic waves. Major earthquakes can trigger hazardous events like tsunamis, which are massive sea waves that cause extensive damage and loss of life when they reach coastal areas. Living in earthquake and tsunami prone zones presents many risks such as property destruction, disruption of basic services, fires, landslides, and loss of lives.
- An earthquake is a vibration in the earth's crust caused by the sudden release of stored energy in rocks along fault lines.
- Factors like population density, level of preparedness, distance from the epicenter, time of occurrence, and soil type determine the extent of damage from an earthquake in addition to its magnitude.
- Earthquakes can cause hazards like disruption of services, destruction of property, landslides, destruction of infrastructure, loss of life, fires, and tsunamis.
The document discusses the risks and benefits of living near volcanic areas. It describes some key risks such as destruction from volcanic materials, landslides, pollution and effects on weather. It also outlines some benefits including fertile volcanic soil which supports agriculture, building materials and precious minerals, tourism attractions, and geothermal energy. While there are benefits, the document argues that there are more risks compared to benefits of living in volcanic areas, given the threats posed by potential eruptions. Proper management is needed to mitigate the risks and leverage the resources volcanoes provide.
The document discusses a REC that was cancelled on March 10th and rescheduled for either March 18th or 19th from 10am to 12pm at Xinnovate on the topic of convergent plate boundaries. It provides examples of transform plate boundaries like the San Andreas Fault in California and North Anatolian Fault in Turkey, describing how an earthquake in 1906 along the San Andreas Fault caused several hundred kilometers of the North American Plate to shift up to 7 meters in under a minute due to stresses building up and releasing where the Pacific and North American Plates slide past each other.
The document discusses transform plate boundaries and provides examples of the San Andreas Fault in the United States and the North Anatolian Fault in Turkey. It notes that at transform boundaries, plates slide past each other building stress until an earthquake occurs. It then provides details about a 1906 earthquake in California on the San Andreas Fault that caused hundreds of kilometers of movement between tectonic plates in under a minute. The document asks how future plate movement might affect two nearby cities.
Convergent plate boundaries occur where tectonic plates move towards one another. There are three main types:
1) Oceanic-oceanic, where two oceanic plates collide and one subducts under the other, forming ocean trenches.
2) Oceanic-continental, where an oceanic plate subducts under a continental plate, pushing up mountains.
3) Continental-continental, where collision resists subduction and the plates break and fold, forming mountains.
- The document discusses plate tectonics topics including oceanic-oceanic divergence and continental-continental divergence.
- Oceanic-oceanic divergence involves two oceanic plates moving apart, causing magma to rise and form new sea floor through sea-floor spreading, creating a mid-ocean ridge.
- Continental-continental divergence can form rift valleys as the land between diverging continental plates sinks, such as the East African Rift Valley, and may eventually lead to the formation of new oceans.
Temple of Asclepius in Thrace. Excavation resultsKrassimira Luka
The temple and the sanctuary around were dedicated to Asklepios Zmidrenus. This name has been known since 1875 when an inscription dedicated to him was discovered in Rome. The inscription is dated in 227 AD and was left by soldiers originating from the city of Philippopolis (modern Plovdiv).
THE SACRIFICE HOW PRO-PALESTINE PROTESTS STUDENTS ARE SACRIFICING TO CHANGE T...indexPub
The recent surge in pro-Palestine student activism has prompted significant responses from universities, ranging from negotiations and divestment commitments to increased transparency about investments in companies supporting the war on Gaza. This activism has led to the cessation of student encampments but also highlighted the substantial sacrifices made by students, including academic disruptions and personal risks. The primary drivers of these protests are poor university administration, lack of transparency, and inadequate communication between officials and students. This study examines the profound emotional, psychological, and professional impacts on students engaged in pro-Palestine protests, focusing on Generation Z's (Gen-Z) activism dynamics. This paper explores the significant sacrifices made by these students and even the professors supporting the pro-Palestine movement, with a focus on recent global movements. Through an in-depth analysis of printed and electronic media, the study examines the impacts of these sacrifices on the academic and personal lives of those involved. The paper highlights examples from various universities, demonstrating student activism's long-term and short-term effects, including disciplinary actions, social backlash, and career implications. The researchers also explore the broader implications of student sacrifices. The findings reveal that these sacrifices are driven by a profound commitment to justice and human rights, and are influenced by the increasing availability of information, peer interactions, and personal convictions. The study also discusses the broader implications of this activism, comparing it to historical precedents and assessing its potential to influence policy and public opinion. The emotional and psychological toll on student activists is significant, but their sense of purpose and community support mitigates some of these challenges. However, the researchers call for acknowledging the broader Impact of these sacrifices on the future global movement of FreePalestine.
1. LIVING WITH
TECTONIC HAZARDS
a. What is a natural hazard?
b. What is the internal structure of the Earth?
c. What is a tectonic plate?
d. Why do tectonic plates move?
e. What are the different types of plate
boundaries?
2. a. What is a natural hazard?
• A natural hazard is a natural event that threatens
human lives and causes damage to property.
3. a. What is a natural hazard?
Distribution of natural hazards
4. a. What is a natural hazard?
Types of natural hazards:
• Tectonic hazards
• Climate-related hazards
Impacts of natural hazards:
• Large scale
• Small scale
5. a. What is a natural hazard?
• Tectonic hazards are caused by movements in the
Earth’s crust.
• Examples:
–Earthquakes
–Volcanic eruptions
–Tsunamis
6. b. What is the internal structure of the earth?
7. b. What is the internal structure of the earth?
Core
• Composed mostly of iron and nickel
• Divided into inner core + outer core
1. Inner core
– about 1,200 km thick
– solid layer
2. Outer core
– about 2,100 km thick
– liquid layer
• Temperature between 3,000⁰C and 5,000⁰C
8. b. What is the internal structure of the earth?
Mantle
• Mostly solid rock (flows under high temperature and
pressure)
• 2,900 km thick
• Divided into upper mantle + lower mantle
Upper mantle
– a layer of solid rock + asthenosphere
– below uppermost mantle
– rocks close to melting point, easily deformed
• Temperature between 800⁰C and 3,000⁰C
9. b. What is the internal structure of the earth?
Crust
• Outermost layer on which we live
• Oceanic crust is found beneath oceans
• Continental crust is found beneath the continents
• Thickness ranges from a few km to more than 70 km
10. b. What is the internal structure of the earth?
Lithosphere
= Crust + Uppermost mantle
• Makes up the Earth’s rigid outer shell
• When the rocks in the lithosphere melt,
hot molten rock called magma is formed.
11. c. What is a tectonic plate?
• A tectonic plate is made up of the lithosphere
(i.e. crust + uppermost mantle).
• The earth’s crust is broken into several pieces
of tectonic plates.
• These plates move in relation to one another.
• Tectonic plates can be made up of:
– oceanic crust
– continental crust or
– a combination of both
12. c. What is a tectonic plate?
Oceanic crust vs Continental crust
Oceanic Crust
• Located beneath deep
ocean
• Very thin — between 5
and 8 km
• Denser (e.g. basalt)
Continental Crust
• Located beneath land
masses and under
shallow seas
• Very thick — between 30
and 60 km
• Less dense (e.g. granite)
13. d. Why do tectonic plates move?
1. Convection currents
•Convection currents are movements of heat within the
mantle.
•Material in the mantle is heated by the core.
•This causes convection currents in the molten mantle
material.
•Mantle expands, rises and spreads out beneath the plates.
•Plates are dragged along and move away from each other.
•Subsequently, the hot molten mantle cools slightly and sinks,
pulling the plates along
•Hence plates move towards each other.
•The sinking mantle material heats up again as it nears the
core and the whole process repeats.
14. d. Why do tectonic plates move?
Plates moving away from each other
Ocean floor
Plates
moving
towards
each
other
Plates
Plates
moving
towards
each other
Tectonic plates float on molten mantle, driven by heat
energy/convection currents
15. d. Why do tectonic plates move?
2. Slab-pull force
• This occurs when an oceanic plate (denser) subducts
under a less dense plate and pulls the rest of the
plate along.
• The subducting plate drives the downward-moving
portion of convection currents.
• While mantle material away from the subduction
zone drives the rising portion of convection currents.
16. d. Why do tectonic plates move?
Changing positions of the earth’s continents
• Plate movements have altered the distribution of
the earth’s land masses over several hundred
million years.
17. e. What are the different types of plate
boundaries?
18. Types of
movement
Types of plates Landforms Examples
Divergent -
plates move
away from
each other
Oceanic-oceanic plate
divergence
Oceanic ridges Mid-Atlantic Ridge
Continental-continental plate
divergence
Rift valley, volcanoes The Great Rift Valley,
Cascade Range
Convergent -
plates move
towards
each other
Oceanic–oceanic plate
convergence
Oceanic trenches,
volcanoes, island arc
Mariana Trench,
Mount Etna, Mariana
Islands
Continental–oceanic plate
convergence
Ocean trenches,
mountain ranges
Sunda Trench,
Barisan Mountains
Continental–continental plate
convergence
Mountain ranges Himalayas
Transform -
plates move
past each
other
Continental-continental
plates sliding past each other
None St Andreas Fault,
North Anatolian Fault
19. e. What are the different types of plate
boundaries?
1. Oceanic-oceanic plate divergence
20. e. What are the different types of plate
boundaries?
1. Oceanic-oceanic plate divergence
21. e. What are the different types of plate
boundaries?
• Magma rises from the mantle to fill the gap
between the plates as they diverge.
• New sea floor is formed when the magma cools
and solidifies. This process is called sea-floor
spreading.
• Magma rises at the zone of
divergence/spreading zone to form a ridge of
new ocean floor called mid-oceanic ridge.
22. e. What are the different types of plate
boundaries?
• The newly formed (youngest) rocks are closest to
the middle of the ridge/plate boundaries.
• At various points along the ridge, magma builds up
above the ocean to form volcanic islands.
• E.g. the Mid-Atlantic Ridge is found in the middle of
the Atlantic Ocean cutting across Iceland, a volcanic
island.
23. e. What are the different types of plate
boundaries?
2. Continental–continental plate divergence
• Can result in the breakup of continents
• E.g. Great Rift Valley (East Africa)
– a lowland with steep sides and flat valley floor
– formed by Somalian boundary of the African Plate
moving away from the Nubia plate boundary of the
African Plate
– 6,000 kilometres long
– between 30 to 100 kilometres wide
– Evidence of tectonic activity: active volcanoes and
earthquake fractures found
24. e. What are the different types of plate
boundaries?
• Can result in the formation of linear sea
• E.g. Red Sea and Gulf of Aden near the Great
Rift Valley
– Elongated/linear shape
– 1,900 km long
– 300 km at its widest stretch
– Average depth of 500 m
– Evidence of tectonic activity — formation of new
volcanic island in Red Sea
25. e. What are the different types of plate
boundaries?
1. Oceanic–oceanic plate convergence
• When two oceanic plates converge, one subducts
under the other.
• A subduction zone forms, creating a deep oceanic
trench.
• The subduction of the oceanic plate causes the solid
mantle material to melt and magma is formed.
• The magma rises through the mantle and ocean floor
to emerge as volcanoes.
• Eventually a chain or arc of islands called island arc is
formed.
26. e. What are the different types of plate
boundaries?
1. Oceanic–oceanic plate convergence
• Earthquakes may also occur.
• E.g. the Pacific Plate converging with the slower-moving
Philippine plate
27. e. What are the different types of plate
boundaries?
1. Oceanic–Oceanic plate convergence
28. e. What are the different types of plate
boundaries?
Locate the Indonesia Archipelago and Japan. Explain the
shape and distribution of these islands.
29. e. What are the different types of plate
boundaries?
2. Continental-continental plate convergence
• Plates made largely of continental crust may collide
with other plates made largely of continental crust.
• However, both plates have similar densities and
hence, resist subduction.
• Instead, the plates break, slide along fractures in the
crust and fold, forming fold mountains.
• E.g. the Himalayas - convergence of the Indian Plate
and the Eurasian Plate.
30. e. What are the different types of plate
boundaries?
E.g. the Himalayas
Continental crust
Continental crust
Himalayas
Tibetan
Plateau
Uppermost mantle
Asthenosphere
EURASIAN
PLATE
INDIAN
PLATE
31. e. What are the different types of plate
boundaries?
3.Oceanic-continental plate convergence
• When an oceanic plate meets a continental plate, the
denser oceanic plate subducts under the less dense
continental plate.
• A subduction zone forms, creating a deep oceanic
trench along the plate boundary.
• The subduction of the continental plate causes the
soild mantle material to melt and magma is formed.
32. e. What are the different types of plate
boundaries?
3.Oceanic-continental plate convergence
• The magma rises through the mantle and crust to
emerge as volcanoes on land.
• The edge of thick continental plate buckles to form
fold mountains.
• Earthquakes may also occur.
• E.g. the Australian Plate subducting under a section
of the Eurasian Plate near Sumatra formed the Sunda
Trench.
33. e. What are the different types of plate
boundaries?
3.Oceanic-continental plate convergence
34. e. What are the different types of plate
boundaries?
3.Oceanic-continental plate convergence
35. e. What are the different types of plate
boundaries?
Transform plate boundaries
• Plates slide past each other.
• As they do so, tremendous stress builds up.
• This stress is eventually released, often as a violent
earthquake.
• E.g. San Andreas Fault, United States of America &
North Anatolian Fault, Turkey
36. e. What are the different types of plate
boundaries?
Transform plate boundaries
37. e. What are the different types of plate
boundaries?
E.g. San Andreas Fault, United States of America
• In 1906, an earthquake occurred in San
Francisco, southern California between the
Pacific Plate and the North American Plate.
– This caused several hundred kilometres of
North American Plate to move an average of
2.5 m,
– and at one point almost 7 m all in less than 1
minute.
38. e. What are the different types of plate
boundaries?
E.g. San Andreas Fault, USA
39. e. What are the different types of plate
boundaries?
E.g. North Anatolian Fault, Turkey
How would the plate movement affect the two
cities shown in time to come?
40. a. Why are different landforms found at
different plate boundaries and how are they
formed?
• The movement of plates at different
plate boundaries can result in various
landforms such as:
- Fold mountains
- Rift valleys and block mountains
- Volcanoes
41. Fold mountains
• Over millions of years, the folding of rocks creates a
landform called fold mountains.
• The Himalayas, the Rocky Mountains and the Andes
are examples of fold mountains.
42. Fold mountains
• Fold mountains are formed along convergent
plate boundaries.
• The compressional force causes the layers of
rocks to buckle and fold.
• This process is known as folding.
43. Fold mountains
• The upfold is called the anticline and
• The downfold is the syncline.
• When there is increasing compressional force on one
limb of a fold, the rocks may buckle until a fracture
forms.
• The limb may then move forward to ride over the
other limb
44. Fold mountains
The Himalayas
Peak : Mount Everest (between
Nepal and Tibet)
Elevation : 8,848 metres
45. Fold mountains
• Fold mountains are located along convergent plate
boundaries
46. Rift valleys and block mountains
• Rift valleys and block mountains are formed at
divergent plate boundaries.
47. Rift valleys and block mountains
• A fault is a fracture in the rocks along which
the rocks are displaced.
• The tensional forces result in parts of the
crust being fractured.
• This process is called faulting.
48. Rift valleys and block mountains
• A rift valley is a valley with steep sides formed along
fault lines.
• E.g. East African Rift Valley
49. Rift valleys and block mountains
• A block mountain is a block of land with steep sides.
It is formed when sections of the crust extend along
fault lines and rock masses surrounding a central
block sink due to tensional forces.
50. Rift valleys and block mountains
The East African Rift Valley
Is formed from the Nubian
section of the African Plate and
the Somalian section of the
African Plate pulling away from
one another.
51. Rift valleys and block mountains
• Distribution of rift valleys and block mountains
52. Volcanoes
• A volcano is a landform formed by magma ejected
from the mantle onto the earth’s surface.
Mount Saint Helens volcano before and after an eruption in May
1980
53. Volcanoes
• Magma is molten rock found below the earth’s
surface.
• Parts of a Volcano
- magma chamber
- vents
• Magma that is ejected onto the surface is known
as lava.
55. Volcanoes
Shapes and sizes of volcanoes
• Volcanoes vary in shapes and sizes due to the
characteristics of the lava.
• Viscosity refers to the stickiness of the lava
• The most common types of volcanoes are:
- Shield volcanoes; and
- Stratovolcanoes
56. Volcanoes
Shield volcanoes
• Shield volcanoes have gently sloping sides and a
broad summit
• E.g. Mount Washington, United States of America
57. Volcanoes
Stratovolcanoes
• Stratovolcanoes develop from successive eruptions of
lava and ash.
• E.g. Mount Mayon, Philippines
59. b. What phenomena are found at plate
boundaries and how are they formed?
• An earthquake is a vibration in the earth’s crust caused by the
sudden release of stored energy in the rocks found along
fault lines.
60. Earthquakes
• Apart from its magnitude, the extent of damage
caused by an earthquake may vary based on other
factors:
- Population density
- time of occurrence
- level of preparedness
- distance from the epicentre
- type of soil
62. Earthquakes
Hazards associated with living in earthquakes zones
- Threat of tsunamis
- Disruption of services
- Fires
- Landslides
- Destruction of properties
- Destruction of infrastructure
- Loss of lives
63. Hazards associated with earthquakes
Threat of tsunamis
• Tsunami refers to an usually large sea wave.
• Tsunamis may be formed by:
- The movement of the sea floor during a large earthquake
at subduction zones;
- An underwater volcanic eruption;
- An underwater landslide; and
- A landslide above sea level which causes materials to
plunge into the water.
65. Hazards associated with earthquakes
Disruption of services
• An earthquake can disrupt services such as the
supply of electricity, gas and water.
• The earthquake in Kobe, Japan, in 1995 disrupted
electricity, gas and water supplies to about a million
of Kobe city’s 1.4 million residents.
Fire
- Earthquakes may rupture gas pipes and this can provide
fuel to start fires.
- For example, the earthquake in Kobe, Japan, in 1995
caused extensive fires.
66. Hazards associated with earthquakes
Landslides
• Landslides are rapid downslope movements of soil,
rock and vegetation.
• Mudflows may also occur when there is heavy
rainfall.
Destruction of properties
• Earthquakes can cause destruction to many homes.
• People may be without homes after the disaster.
67. Hazards associated with earthquakes
Loss of lives
• Earthquakes and their associated hazards often
threaten the lives of those living in earthquake zones.
Destruction of infrastructure
• Earthquakes may cause cracks to form in
infrastructure such as roads and bridges.
• Transportation can be disrupted as it is unsafe to use
the damaged roads.
69. b. What phenomena are found at plate
boundaries and how are they formed?
Volcanic eruptions
- Occurs on land occur on the sea floor.
Active, dormant or extinct
• Active volcanoes refers to volcanoes which are currently
erupting or are expected to erupt in the future.
• Dormant volcanoes are currently inactive but may erupt
in the near future.
• Extinct volcanoes refers to volcanoes without current
seismic activity
70. Volcanic eruptions
Risks of living near volcanic areas
Some of the risks associated with living near volcanic
areas include:
• Destruction by volcanic materials
• Landslides
• Pollution
• Effects on weather
71. Volcanic eruptions
Destruction by volcanic materials
• Volcanic materials can lead to widespread damage of
property.
Landslides
• Landslides can occur due to the structural collapse of a
volcanic cone.
• Obstruct the flow of rivers which causes floods,
• block roads, and
• bury villages and farmlands.
72. Volcanic eruptions
Pollution
• Ash particles may block sunlight, suffocate crops, and
cause severe respiratory problems for people and
animals.
• Release of gases may be harmful to people.
74. Volcanic eruptions
Effects on weather
• Sulphur dioxide released from volcanic eruptions
has impacts on the environment
• It may react with water vapour and other
chemicals in the atmosphere to form sulphur-based
particles.
• These particles reflect the sun’s energy back into
space and temporarily cool the earth for periods
of time.
75. Volcanic eruptions
Benefits of living near volcanic areas
• Fertile volcanic soil
• Building materials, and precious stones and
materials
• Tourism
• Geothermal energy
76. Volcanic eruptions
Tourism
• Volcanic areas offer a variety of activities for
tourists to engage in.
• The ruins of Pompeii, Italy, is one such example.
Pompeii was partially
destroyed and buried
under 4 to 6 m (13 to 20
ft) of ash and pumice in
the eruption of Mount
Vesuvius in CE 79.
77. Volcanic eruptions
Geothermal energy
• Geothermal energy is derived from the heat in the
earth’s crust.
• The hot water or steam can be harnessed to produce
electricity.
78. Volcanic eruptions
Fertile volcanic soil
• Lava and ash from the volcanic eruptions break down
to form fertile volcanic soils.
• Favourable to agriculture
Precious stones and minerals, building materials
• Volcanic rocks can be rich in precious stones and
minerals.
• These resources can only be from a volcanic area after
millions of years.
• An example is diamond.
Editor's Notes
Suggested activity:
Ask students to read the article on http://www.channelnewsasia.com/stories/singaporelocalnews/view/337625/1/.html.
Prompt them to explain if the incident is a natural hazard.
Suggested activity
Recap the internal structure of the earth with students with the website: http://www.learner.org/interactives/dynamicearth/structure.html
Suggested activity:
Demonstrate convection currents with the video: http://www.youtube.com/watch?v=PdWYBAOqHrk&feature=fvwrel
Suggested activity:
Let students watch a video on the changing positions of the earth’s continents: http://www.youtube.com/watch?v=WaUk94AdXPA
Suggested activity:
Let students watch a video on seafloor spreading: http://earthguide.ucsd.edu/eoc/teachers/t_tectonics/p_paleomag.html
An example of a volcanic island formed from oceanic-oceanic plate divergence is Iceland. Let students watch a video on it: http://www.youtube.com/watch?v=_rG6q2Npw8Y&feature=related
Suggested activity:
For Express students
Let students learn more about the Red Sea and Gulf of Aden from: http://gln.dcccd.edu/Geology_Demo/content/Lesson1/GEO01-20.swf
For Express students
Suggested activity:
Let students watch a video on continental-continental plate convergence: http://www.youtube.com/watch?v=ngV66m00UvU&feature=related
Suggested activity
Let students learn more by visiting the website: http://www.youtube.com/watch?v=ZxPTLmg0ZCw
For Express students
Suggested activity:
Ask students -
1. Why are compressional forces only felt at convergent plate boundaries?
At convergent plate boundaries, the direction of movement of convection currents cause plates to move
towards each other.
Suggested activity:
Ask students to identify the plate boundaries along which the Himalayas are located.
Eurasian Plate and Indian Plate
Explain to students the difference between faulting and folding.
Folding is (i) caused due to horizontal movements. (ii) Forces move towards a common centre. (iii) Due to compression, different types of folds are formed.
Faulting is (i) caused generally due to vertical movements. (ii) Forces move away from the common centre. (iii) Due to tension, faults occur along which displacement of rocks take place.
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Explain to students the difference between a fold mountain and a block mountain.
Block mountains are formed by the downward movement of masses of land along lines of weakness while fold mountains are formed from the sideways motion of land being compressed.
Suggested activity:
Compare the maps on i) the location of fold mountains and ii) the location of rift valleys and block mountains. Describe the relationship between the plate boundaries and the location of fold mountains, rift valleys and block mountains.
The landforms are located along the plate boundaries.
Locations of fold mountains and block mountains are generally different.
Except along the Eurasian and African plates, there is a cluster of block mountains, rift valleys and fold mountains.
Suggested activity:
Ask students to visit the website http://www.bbc.co.uk/science/earth/surface_and_interior/lava to learn more about lava.
Explain to students that stratovolcanoes tend to form at subduction zones, where an oceanic plate slides beneath a continental plate and contributes to the rise of magma to the surface.
Shield volcanoes tend to form at zones where two oceanic plates divergeand magma moves upward through the gap.
The Pacific Ring of Fire is a roughly horseshoe shaped ring around the Pacific Basin. It marks the area or
ring of greatest seismic activity in the world, and it is where the most earthquakes and volcanic activity occurs.
Suggested activity:
Ask students to describe the location of the earth’s major earthquakes.
Along plate boundaries.
How does earthquakes lead to landslides ?
Suggested activity:
Allow students to visit the website: http://abcnews.go.com/Archives/video/jan-17-1995-earthquake-japan-9421417.
Ask them about the effects of the earthquake they observe from the video.
Fires, collapsed buildings and infrastructure, floods, lives lost, people made homeless, people trapped under rubble
Suggested activity:
Ask students to explain why the earthquake that took place in Haiti (magnitude 7.0) caused more damage and higher number of deaths than the earthquake that took place in Tohoku, Japan (magnitude 9.0).
The earthquake in Haiti could have taken place in areas that are densely populated as compared to Tohoku.
The people in Tohoku, Japan could be more prepared to deal with earthquakes than the people in Haiti.
The structures of the buildings in Japan are more earthquake-resistant.
Suggested activity:
Ask students to visit the following website to learn more about how the eruption of Eyjafjallajokull affected jets.
http://mountaincatgeology.wordpress.com/2011/02/19/the-2010-eruptions-ofeyjafjallajokull
Suggested activity
Ask students if it is possible to harness geothermal energy in Singapore.
No, Singapore is not located within a tectonic zone.