Document
... The total subsidence in an extensional basin is made of two components: an initial fault controlled subsidence which is dependent on the initial thickness of the crust and the amount of stretching beta; and a subsequent thermal subsidence caused by relaxation of lithospheric isotherms to their pre-s ...
... The total subsidence in an extensional basin is made of two components: an initial fault controlled subsidence which is dependent on the initial thickness of the crust and the amount of stretching beta; and a subsequent thermal subsidence caused by relaxation of lithospheric isotherms to their pre-s ...
Stress and Strain - Academic Home Page
... At the surface of Earth, the principal stress directions must be parallel or perpendicular to a principal stress plane ...
... At the surface of Earth, the principal stress directions must be parallel or perpendicular to a principal stress plane ...
Magmatic and tectonic evolution of the North Atlantic Journal of the
... Following the breakup of Pangaea at c. 55 Ma the North Atlantic has experienced extensive volcanism. As one of the large igneous provinces of the world, this region is influenced by the Iceland hotspot. This hotspot is often considered to be the surface expression of a convection plume of anomalousl ...
... Following the breakup of Pangaea at c. 55 Ma the North Atlantic has experienced extensive volcanism. As one of the large igneous provinces of the world, this region is influenced by the Iceland hotspot. This hotspot is often considered to be the surface expression of a convection plume of anomalousl ...
subduction zones
... Subduction Zones Subduction zones only occur at convergent boundaries between oceans and continents, and oceans and oceans When oceanic lithosphere converges with continental lithosphere it is the oceanic material that is always subducted beneath the continental material. When the convergent bo ...
... Subduction Zones Subduction zones only occur at convergent boundaries between oceans and continents, and oceans and oceans When oceanic lithosphere converges with continental lithosphere it is the oceanic material that is always subducted beneath the continental material. When the convergent bo ...
PDF
... manifestations begin synchronously? The oldest of each are not the same age—the oldest ophiolites, ca. 1.03 Ga, are significantly older than the oldest blueschists, ca. 800 Ma, and these are older than the oldest-known UHP terranes. Such a progression is expected from our understanding of the subduc ...
... manifestations begin synchronously? The oldest of each are not the same age—the oldest ophiolites, ca. 1.03 Ga, are significantly older than the oldest blueschists, ca. 800 Ma, and these are older than the oldest-known UHP terranes. Such a progression is expected from our understanding of the subduc ...
Active rifting and crustal thinning along the Rivera
... The El Gordo graben lies within the oceanic lithosphere west of the Middle America Trench at 18.15°N, 104.7°W. This graben has been proposed to mark the southwest tip of an active zone of extension located between the Rivera and Cocos plates. The results of an analysis of the Mantle Bouguer gravity ...
... The El Gordo graben lies within the oceanic lithosphere west of the Middle America Trench at 18.15°N, 104.7°W. This graben has been proposed to mark the southwest tip of an active zone of extension located between the Rivera and Cocos plates. The results of an analysis of the Mantle Bouguer gravity ...
A Dynamic Model of Rifting Between Galicia Bank and Flemish Cap
... Regardless of the complexities of late rift-stage and early spreading phase melt production, there is broad consensus that for most of the rift history the margins were amagmatic, or at least involved very little melt production. Volcanism that occurred prior to the onset of seafloor spreading appea ...
... Regardless of the complexities of late rift-stage and early spreading phase melt production, there is broad consensus that for most of the rift history the margins were amagmatic, or at least involved very little melt production. Volcanism that occurred prior to the onset of seafloor spreading appea ...
subduction zones
... Subduction Zones Subduction zones only occur at convergent boundaries between oceans and continents, and oceans and oceans When oceanic lithosphere converges with continental lithosphere it is the oceanic material that is always subducted beneath the continental material. When the convergent bo ...
... Subduction Zones Subduction zones only occur at convergent boundaries between oceans and continents, and oceans and oceans When oceanic lithosphere converges with continental lithosphere it is the oceanic material that is always subducted beneath the continental material. When the convergent bo ...
From Lithospheric Thickening and Divergent Collapse to Active
... This process increases the gravitational potential energy of the thickened lithosphere producing tensile horizontal stresses that may trigger divergent collapse: The gravity-driven flow that reduces lateral variation of gravitational potential energy. As collapse proceeds, the thickened crust tends ...
... This process increases the gravitational potential energy of the thickened lithosphere producing tensile horizontal stresses that may trigger divergent collapse: The gravity-driven flow that reduces lateral variation of gravitational potential energy. As collapse proceeds, the thickened crust tends ...
IM_chapter2 Plate Tectonics
... 3. Why was the concept of seafloor spreading necessary for continental drift to be accepted? How could scientists ignore the overwhelming evidence that the continents could move over the face of the Earth? 4. Demonstrate the relationship between hot spots and surface volcanic chains with a piece of ...
... 3. Why was the concept of seafloor spreading necessary for continental drift to be accepted? How could scientists ignore the overwhelming evidence that the continents could move over the face of the Earth? 4. Demonstrate the relationship between hot spots and surface volcanic chains with a piece of ...
Chapter 2 - Test Bank 1
... 3. Why was the concept of seafloor spreading necessary for continental drift to be accepted? How could scientists ignore the overwhelming evidence that the continents could move over the face of the Earth? 4. Demonstrate the relationship between hot spots and surface volcanic chains with a piece of ...
... 3. Why was the concept of seafloor spreading necessary for continental drift to be accepted? How could scientists ignore the overwhelming evidence that the continents could move over the face of the Earth? 4. Demonstrate the relationship between hot spots and surface volcanic chains with a piece of ...
Contribution of gravitational potential energy differences to the
... et al. 2006, 2008). The assumption that goes with the thin sheet approximation is that the gradients of shear tractions at the base of the plate are negligibly small compared to the force of gravity acting on density. In terms of a thin sheet approach, the sources of stress within the lithosphere ca ...
... et al. 2006, 2008). The assumption that goes with the thin sheet approximation is that the gradients of shear tractions at the base of the plate are negligibly small compared to the force of gravity acting on density. In terms of a thin sheet approach, the sources of stress within the lithosphere ca ...
Crustal geophysical research helps constrain the nature of mantle
... structure is in this case similar to that of normal oceanic crust. Some examples of this are the Ontong-Java, North Atlantic or Galápagos Volcanic Provinces (GVP) (see Table I). As shown in this Table, the main difference is the thicker crust with respect to that of normal oceanic crust. Regardless ...
... structure is in this case similar to that of normal oceanic crust. Some examples of this are the Ontong-Java, North Atlantic or Galápagos Volcanic Provinces (GVP) (see Table I). As shown in this Table, the main difference is the thicker crust with respect to that of normal oceanic crust. Regardless ...
geologic trips to the Sea Ranch
... they accumulated in shallow water. The flanks of the ocean basin were steep, so that periodically the sediments became unstable, probably during storms or earthquakes. When the sediments became unstable, they mixed with sea water and formed a dense turbidity flow that moved down the flank of the bas ...
... they accumulated in shallow water. The flanks of the ocean basin were steep, so that periodically the sediments became unstable, probably during storms or earthquakes. When the sediments became unstable, they mixed with sea water and formed a dense turbidity flow that moved down the flank of the bas ...
Upper mantle beneath Southeast Asia from S velocity tomography
... multiple S waves. The observed range of S velocity variations is the widest (17–18%) in the upper 150 km of the mantle. High-velocity continental roots can reach beyond the present extent of the overlying Archean-Proterozoic crust by 500 km. Beneath some Precambrian units the roots are absent, which ...
... multiple S waves. The observed range of S velocity variations is the widest (17–18%) in the upper 150 km of the mantle. High-velocity continental roots can reach beyond the present extent of the overlying Archean-Proterozoic crust by 500 km. Beneath some Precambrian units the roots are absent, which ...
Lithospheric Removal as aTrigger for Flood
... clear migration pattern (Fig. 2b; Nieto-Obrego¤n et al., 1981; Moore et al., 1994; Ferrari et al., 2000; Rosas-Elguera et al., 2003), indicating that the ‘flood basalts’ began erupting almost simultaneously over this vast territory, and that this event occurred within a relatively short time span, a ...
... clear migration pattern (Fig. 2b; Nieto-Obrego¤n et al., 1981; Moore et al., 1994; Ferrari et al., 2000; Rosas-Elguera et al., 2003), indicating that the ‘flood basalts’ began erupting almost simultaneously over this vast territory, and that this event occurred within a relatively short time span, a ...
Geodynamical interpretation of crustal and upper mantle electrical conductivity
... low P-wave velocities of 7.7–7.8 km/s correspond to partially molten material as a feature of the asthenosphere. To answer these questions we need to investigate spatial and physical relationships between the anomalous mantle revealed by Rogozhina and Kozhevnikov (1979) and the lowvelocity lens (Kry ...
... low P-wave velocities of 7.7–7.8 km/s correspond to partially molten material as a feature of the asthenosphere. To answer these questions we need to investigate spatial and physical relationships between the anomalous mantle revealed by Rogozhina and Kozhevnikov (1979) and the lowvelocity lens (Kry ...
CT Science Center
... This package provides you and your students with pre visit, visit and post visit materials related to the topic of geologic forces. Specifically how do constructive and destructive forces shape the Earth’s surface? We have focused the investigations on how have those constructive and destructive for ...
... This package provides you and your students with pre visit, visit and post visit materials related to the topic of geologic forces. Specifically how do constructive and destructive forces shape the Earth’s surface? We have focused the investigations on how have those constructive and destructive for ...
seismic activity, Yangtze River – Yellow Sea seismic belt, trend
... analysis. One method is to compare characteristics of seismic active period, include the lasting time duration, seismicity level (number of strong earthquakes, total released energy, etc.), and evolution characteristics of the seismicity process, etc; and predict the characteristics of future seismi ...
... analysis. One method is to compare characteristics of seismic active period, include the lasting time duration, seismicity level (number of strong earthquakes, total released energy, etc.), and evolution characteristics of the seismicity process, etc; and predict the characteristics of future seismi ...
Deformation in the asthenospheric mantle beneath the Carpathian
... groups could be distinguished. The first group might represent the new juvenile part of the lithosphere which has been accreted from the asthenosphere since the end of the extension in the thermal relaxation stage [Kovács et al., 2012]. Since the focus of the present study is on the upper mantle, we ...
... groups could be distinguished. The first group might represent the new juvenile part of the lithosphere which has been accreted from the asthenosphere since the end of the extension in the thermal relaxation stage [Kovács et al., 2012]. Since the focus of the present study is on the upper mantle, we ...
Plate Tectonics Questions
... Some fragments taken from the site have a nickel-iron composition. This evidence indicates that the crater probably was formed by A) the impact of a meteorite from space B) the collapse of a cavern roof C) an eruption of a volcano D) an underwater explosion of steam ...
... Some fragments taken from the site have a nickel-iron composition. This evidence indicates that the crater probably was formed by A) the impact of a meteorite from space B) the collapse of a cavern roof C) an eruption of a volcano D) an underwater explosion of steam ...
Plate Tectonics and Earthquakes
... The Father of Plate Tectonics John Tuzo Wilson was born in Ottawa in 1908, the first child of Henrietta Tuzo and John Armistead Wilson (Figure 3.5). His mother was an accomplished mountaineer and his father an engineer. This heritage was reflected by Tuzo Wilson’s choice of studies: he graduated fro ...
... The Father of Plate Tectonics John Tuzo Wilson was born in Ottawa in 1908, the first child of Henrietta Tuzo and John Armistead Wilson (Figure 3.5). His mother was an accomplished mountaineer and his father an engineer. This heritage was reflected by Tuzo Wilson’s choice of studies: he graduated fro ...
rift valley - National Geographic
... steep volcano made of hardened lava, rock, and ash. Also known as a composite volcano. process of one tectonic plate melting, sliding, or falling beneath another. ancient, giant landmass that split apart to form all the continents we know today. movement of tectonic plates resulting in geologic acti ...
... steep volcano made of hardened lava, rock, and ash. Also known as a composite volcano. process of one tectonic plate melting, sliding, or falling beneath another. ancient, giant landmass that split apart to form all the continents we know today. movement of tectonic plates resulting in geologic acti ...
Upper mantle and lithospheric heterogeneities in central
... Table 1. Station parameters, Moho Ps delay times t Ps , amplitudes of Moho conversions relative to primary P wave (A), Moho depth (H) and V p /V s ratios obtained by the method of Zhu & Kanamori (2000), number of stacked traces n. The delay times of the P 410 s and P 660 s are given, as well as the ...
... Table 1. Station parameters, Moho Ps delay times t Ps , amplitudes of Moho conversions relative to primary P wave (A), Moho depth (H) and V p /V s ratios obtained by the method of Zhu & Kanamori (2000), number of stacked traces n. The delay times of the P 410 s and P 660 s are given, as well as the ...
Melting features along the Ryukyu slab tear, beneath the
... are depths of the Ryukyu slab (adapted from Font et al. [1999] in the western part). The dashed line shows the location of the Huatung Basin/western PH Sea plate boundary underlined by a negative free-air anomaly trend [Hsu et al., 1998] and located just east of Gagua Ridge. Its northern prolongatio ...
... are depths of the Ryukyu slab (adapted from Font et al. [1999] in the western part). The dashed line shows the location of the Huatung Basin/western PH Sea plate boundary underlined by a negative free-air anomaly trend [Hsu et al., 1998] and located just east of Gagua Ridge. Its northern prolongatio ...
Post-glacial rebound
.jpg?width=300)
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.