The Lithosphere – Asthenosphere System: Nature of the Tectonic
... and compositional coupling between rigid plates and underlying convecting mantle. Seismological studies reveal distinct reflectors (G discontinuity) in the uppermost oceanic mantle that are sometimes interpreted as the LAB. These reflectors roughly correlate with the location of discontinuities in r ...
... and compositional coupling between rigid plates and underlying convecting mantle. Seismological studies reveal distinct reflectors (G discontinuity) in the uppermost oceanic mantle that are sometimes interpreted as the LAB. These reflectors roughly correlate with the location of discontinuities in r ...
y - diss.fu
... It was just 200 years later, when the first attempts were made to determine the shape of the earth, that it was possible to estimate the equilibrium state of mountains. The concept of isostasy was discovered during the late 1880’s as part of a geodetic survey of northern India, and describes the com ...
... It was just 200 years later, when the first attempts were made to determine the shape of the earth, that it was possible to estimate the equilibrium state of mountains. The concept of isostasy was discovered during the late 1880’s as part of a geodetic survey of northern India, and describes the com ...
Lithospheric buoyancy forces in Africa from a thin sheet approach
... Many features in rift zones and passive margins have been successfully explained by lithospheric stretching models (e.g., McKenzie 1978; Wernicke 1981; Lister et al. 1986; Whitmarsh et al. 2001), which assume that lithospheric thinning and crustal extension are driven by far-field stresses from plat ...
... Many features in rift zones and passive margins have been successfully explained by lithospheric stretching models (e.g., McKenzie 1978; Wernicke 1981; Lister et al. 1986; Whitmarsh et al. 2001), which assume that lithospheric thinning and crustal extension are driven by far-field stresses from plat ...
Cenozoic plate tectonic reconstructions of SE Asia
... Approximately sixty fragments were used, and they retain their current size in order that they remain recognisable. However, in earlier reconstructions it is likely that fragments had different sizes and shapes or may not have existed, for example in areas of volcanism and extension in the Philippin ...
... Approximately sixty fragments were used, and they retain their current size in order that they remain recognisable. However, in earlier reconstructions it is likely that fragments had different sizes and shapes or may not have existed, for example in areas of volcanism and extension in the Philippin ...
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... Lower crustal dipping reflectors have reported by previous seismic studies in the Pacific. New observations: -Lower crustal dipping reflectors coexist with high velocity / anisotropic mantle immediately below Moho ...
... Lower crustal dipping reflectors have reported by previous seismic studies in the Pacific. New observations: -Lower crustal dipping reflectors coexist with high velocity / anisotropic mantle immediately below Moho ...
Plate bending at subduction zones
... half-space cooling model [15] for ages less than 81 Ma and to a simple parametric function for ages greater than 81 Ma [14], although the results are not changed substantially if we adopt a half-space cooling model for all ages. The age of the plate is inferred from magnetic anomalies on the seafloo ...
... half-space cooling model [15] for ages less than 81 Ma and to a simple parametric function for ages greater than 81 Ma [14], although the results are not changed substantially if we adopt a half-space cooling model for all ages. The age of the plate is inferred from magnetic anomalies on the seafloo ...
Models of Mantle Convection Incorporating Plate Tectonics: The
... because there are large-scale features which cannot be explained by application of plate tectonics, but which may be associated with the radial motion of buoyancy within the mantle. The two perplexing features which we focus on here include the complete subaerial exposure of the Australian continent ...
... because there are large-scale features which cannot be explained by application of plate tectonics, but which may be associated with the radial motion of buoyancy within the mantle. The two perplexing features which we focus on here include the complete subaerial exposure of the Australian continent ...
A climate induced transition in the tectonic style of a terrestrial planet
... tectonics on present day Earth. If convective stress levels fall below the yield stress, then weak margins cannot be generated and an active-lid mode of convection will cease (Moresi and Solomatov, 1998). We assume that long-lived surface temperature changes affect internal mantle temperature, Ti, a ...
... tectonics on present day Earth. If convective stress levels fall below the yield stress, then weak margins cannot be generated and an active-lid mode of convection will cease (Moresi and Solomatov, 1998). We assume that long-lived surface temperature changes affect internal mantle temperature, Ti, a ...
Mull and Iona - Scottish Natural Heritage
... Deformed and metamorphosed late-Precambrian sedimentary rocks (Moine, Dalradian and rocks of eastern Iona). ...
... Deformed and metamorphosed late-Precambrian sedimentary rocks (Moine, Dalradian and rocks of eastern Iona). ...
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... are driven largely by slab pull. This mechanism accounts for the opening of the Atlantic, the ability of spreading ridges to stay o n the midlines of oceans, and the penetration of India into Asia following their collision. Continental motions strongly imply lower mantle upwelling and divergence' be ...
... are driven largely by slab pull. This mechanism accounts for the opening of the Atlantic, the ability of spreading ridges to stay o n the midlines of oceans, and the penetration of India into Asia following their collision. Continental motions strongly imply lower mantle upwelling and divergence' be ...
Earthquakes and volcanoes CH. 11
... • Volcanoes on Earth usually form along rift zones, subduction zones (where one plate sinks beneath another), or over hot spots. • At each of these locations lava breaks through and flows out, where it piles up into layers or forms a volcanic cone. ...
... • Volcanoes on Earth usually form along rift zones, subduction zones (where one plate sinks beneath another), or over hot spots. • At each of these locations lava breaks through and flows out, where it piles up into layers or forms a volcanic cone. ...
1-Movement of Crustal Plates - Fellows
... The Theory of Continental Drift Not until the 1960’s did Holmes’ idea receive any attention. Greater understanding of the ocean floor and the discoveries of features like mid-ocean ridges, geomagnetic anomalies parallel to the mid-ocean ridges, and the association of island arcs and oceanic trenche ...
... The Theory of Continental Drift Not until the 1960’s did Holmes’ idea receive any attention. Greater understanding of the ocean floor and the discoveries of features like mid-ocean ridges, geomagnetic anomalies parallel to the mid-ocean ridges, and the association of island arcs and oceanic trenche ...
ADVANCED LEVEL GEOGRAPHY
... -- When convectional currents of magma in the upper mantle converge and sink, this causes one plate to move towards to other and the plates collide. -- The oceanic crust on either side of the mid-oceanic ridge is moving toward the thick mass of continental lithosphere. Because the oceanic plate is c ...
... -- When convectional currents of magma in the upper mantle converge and sink, this causes one plate to move towards to other and the plates collide. -- The oceanic crust on either side of the mid-oceanic ridge is moving toward the thick mass of continental lithosphere. Because the oceanic plate is c ...
The Origin of the Land Under the Sea
... same scientists strove to explain what fuels these erupting mountain ranges, called midocean ridges. Basic theories suggest that because ocean crust pulls apart along the ridges, hot material deep within the earth’s rocky interior must rise to fill the gap. But details of exactly where the lava orig ...
... same scientists strove to explain what fuels these erupting mountain ranges, called midocean ridges. Basic theories suggest that because ocean crust pulls apart along the ridges, hot material deep within the earth’s rocky interior must rise to fill the gap. But details of exactly where the lava orig ...
0622932 COVER SHEET FOR PROPOSAL TO THE NATIONAL SCIENCE FOUNDATION NSF 02-011
... Understanding oceanic lithosphere, which spans the birth of plates at mid-ocean ridges to their interment at subduction zones, is central to understanding plate tectonics. However, while slab pull is generally accepted as the dominant driving force of plate tectonics, the interaction of plates with ...
... Understanding oceanic lithosphere, which spans the birth of plates at mid-ocean ridges to their interment at subduction zones, is central to understanding plate tectonics. However, while slab pull is generally accepted as the dominant driving force of plate tectonics, the interaction of plates with ...
Magnesium isotopic composition of the lower continental crust
... differentiation make Mg isotopes a potentially powerful tracer of the influence of chemical weathering on the continental crust composition. Magnesium isotopic composition of the upper continental crust is highly heterogenous [1], and on avarage heavier than the mantle [e.g., 2]. By contrast, the Mg ...
... differentiation make Mg isotopes a potentially powerful tracer of the influence of chemical weathering on the continental crust composition. Magnesium isotopic composition of the upper continental crust is highly heterogenous [1], and on avarage heavier than the mantle [e.g., 2]. By contrast, the Mg ...
The Bouguer gravity map of the Mediterranean Sea
... maps are no longer relevant for the following discussion and models. The values of gravity observed at the Earth's surface are strongly correlated with terrain morphology and hence with residual effects of tectonics, which are better preserved at sea than on land. In oceanic regions, gravity is also ...
... maps are no longer relevant for the following discussion and models. The values of gravity observed at the Earth's surface are strongly correlated with terrain morphology and hence with residual effects of tectonics, which are better preserved at sea than on land. In oceanic regions, gravity is also ...
Subduction zone backarcs, mobile belts, and orogenic heat
... of several hundred km relative to stable cratonic and platform areas. The effect of crust and upper mantle temperature on elevation has been discussed in detail by Lachenbruch and Morgan (1990). In a simple approximation, the density change due to a 200 °C average temperature difference to a depth o ...
... of several hundred km relative to stable cratonic and platform areas. The effect of crust and upper mantle temperature on elevation has been discussed in detail by Lachenbruch and Morgan (1990). In a simple approximation, the density change due to a 200 °C average temperature difference to a depth o ...
Ocean Rises are Products of Variable Mantle Composition
... Ocean ridges, where Earth’s tectonic plates are pulled apart, vary from more than 5km depth in the Arctic to 750 m above sea level in Iceland. This huge relief is generally attributed to mantle plumes underlying mantle hotspots, areas of enormous volcanism marked by ocean islands. The plumes are tho ...
... Ocean ridges, where Earth’s tectonic plates are pulled apart, vary from more than 5km depth in the Arctic to 750 m above sea level in Iceland. This huge relief is generally attributed to mantle plumes underlying mantle hotspots, areas of enormous volcanism marked by ocean islands. The plumes are tho ...
Essentials of Geology, 3rd edition
... The devastating tsunami killed people in 10 countries surrounding the ...
... The devastating tsunami killed people in 10 countries surrounding the ...
Quiz 2 Fall 2007 Handout Page
... 49.Rocks closer to the spreading centers in the oceans are older than the rocks farther away from the spreading center. a. False b. True ...
... 49.Rocks closer to the spreading centers in the oceans are older than the rocks farther away from the spreading center. a. False b. True ...
Spectrum of Fault Slip Behavior
... • Earthquakes with a distinct nucleation phase • Afterslip and transient postseismic deformation • Normal (fast) earthquakes ...
... • Earthquakes with a distinct nucleation phase • Afterslip and transient postseismic deformation • Normal (fast) earthquakes ...
Slide 1
... – Subduction Boundary • one plate moves under the other – ocean-ocean » deep sea trenches » island arcs – ocean-continent » coastal volcanoes – Collision Boundary • plates push against each other form mtns – continent-continent » Himalays Updated ...
... – Subduction Boundary • one plate moves under the other – ocean-ocean » deep sea trenches » island arcs – ocean-continent » coastal volcanoes – Collision Boundary • plates push against each other form mtns – continent-continent » Himalays Updated ...
UExcel® Official Content Guide for Earth Science
... A UExcel exam enables you to show that you've learned material comparable to one or more 15week, college-level courses. As an independent learner, you should study and review as much as you would for a college course. For a three-credit course in a subject they don't know, most students would be exp ...
... A UExcel exam enables you to show that you've learned material comparable to one or more 15week, college-level courses. As an independent learner, you should study and review as much as you would for a college course. For a three-credit course in a subject they don't know, most students would be exp ...
THE ORIGIN AND GROWTH OF CONTINENTS 1 Geophysical
... is sedimentary. Ewing and Nafe (1963) conclude from the observed hickening near volcanic islands that it is in part volcanic. The question is of interest for the age of the ocean basins, total amount of sedimentation; rates of erosion and geochemical belance calculations generally. However, the atte ...
... is sedimentary. Ewing and Nafe (1963) conclude from the observed hickening near volcanic islands that it is in part volcanic. The question is of interest for the age of the ocean basins, total amount of sedimentation; rates of erosion and geochemical belance calculations generally. However, the atte ...
Post-glacial rebound
Post-glacial rebound (sometimes called continental rebound) is the rise of land masses that were depressed by the huge weight of ice sheets during the last glacial period, through a process known as isostatic depression. Post-glacial rebound and isostatic depression are different parts of a process known as either glacial isostasy, glacial isostatic adjustment, or glacioisostasy. Glacioisostasy is the solid Earth deformation associated with changes in ice mass distribution. The most obvious and direct affects of post-glacial rebound are readily apparent in northern Europe (especially Scotland, Estonia, Latvia, Fennoscandia, and northern Denmark), Siberia, Canada, the Great Lakes of Canada and the United States, the coastal region of the US state of Maine, parts of Patagonia, and Antarctica. However, through processes known as ocean siphoning and continental levering, the effects of post-glacial rebound on sea-level are felt globally far from the locations of current and former ice sheets.