Ch. 10 Crustal Deformation
... displacements of hundreds of kilometers and consist of many interconnecting fault surface. Fault zones can be easy to identify from high-altitude photographs than at ground level. Sudden movements along faults are the cause of most earthquakes. Many faults are inactive and are remnants of past defor ...
... displacements of hundreds of kilometers and consist of many interconnecting fault surface. Fault zones can be easy to identify from high-altitude photographs than at ground level. Sudden movements along faults are the cause of most earthquakes. Many faults are inactive and are remnants of past defor ...
Punctuated tectonic evolution of the earth
... would produce surface swells rivalling the mid-ocean ridge system in extent and amplitude [24,25]. Neither the observed hotspot swells nor the low-amplitude deviations from the square-root-of-age seafloor subsidence, predicted by the cooling boundary layer model of plates, are large enough to repres ...
... would produce surface swells rivalling the mid-ocean ridge system in extent and amplitude [24,25]. Neither the observed hotspot swells nor the low-amplitude deviations from the square-root-of-age seafloor subsidence, predicted by the cooling boundary layer model of plates, are large enough to repres ...
Dehydration of serpentinized slab mantle: Seismic evidence from southwest Japan
... Kanto, the Izu-Bonin fore-arc is subducting (Fig. 1). Beneath Tokai, in contrast, the Izu-Bonin volcanic ridge, i.e., the Izu-Shichito Ridge, is subducting. Suyehiro et al. (1996) detected a low velocity layer in the fore-arc mantle wedge of the Izu-Bonin arc by seismic refraction surveys and sugges ...
... Kanto, the Izu-Bonin fore-arc is subducting (Fig. 1). Beneath Tokai, in contrast, the Izu-Bonin volcanic ridge, i.e., the Izu-Shichito Ridge, is subducting. Suyehiro et al. (1996) detected a low velocity layer in the fore-arc mantle wedge of the Izu-Bonin arc by seismic refraction surveys and sugges ...
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... drag the Caribbean plate eastward by viscous coupling, but it could not be determined whether return ¯ow extended several hundred km down through the entire upper mantle or was con®ned to the asthenosphere. Current interpretations of seismic tomography results suggest that below the asthenosphere th ...
... drag the Caribbean plate eastward by viscous coupling, but it could not be determined whether return ¯ow extended several hundred km down through the entire upper mantle or was con®ned to the asthenosphere. Current interpretations of seismic tomography results suggest that below the asthenosphere th ...
Modified True/False - Indicate whether the
... 41. A. Point B is the epicenter of the earthquake because after all three seismograms calculated their distance from the epicenter and drew a circle of all possible points that the epicenter could be, the one spot where all three circles overlapped is point B. B. They could still be used to determin ...
... 41. A. Point B is the epicenter of the earthquake because after all three seismograms calculated their distance from the epicenter and drew a circle of all possible points that the epicenter could be, the one spot where all three circles overlapped is point B. B. They could still be used to determin ...
The fate of fluids released from subducting slab in
... earthquakes and to collision tectonics. An approximately 10 km thick lower crustal layer of low Poisson’s ratio (σ = 0.22) in the forearc is estimated to represent a maximum addition of ∼14 % by volume of quartz (σ = 0.09). If this quartz is removed from rising silica-saturated fluids over long time ...
... earthquakes and to collision tectonics. An approximately 10 km thick lower crustal layer of low Poisson’s ratio (σ = 0.22) in the forearc is estimated to represent a maximum addition of ∼14 % by volume of quartz (σ = 0.09). If this quartz is removed from rising silica-saturated fluids over long time ...
Grand Challenges in Geodynamics
... Our home planet has reached its current state through 4.56 billion years of dynamic activity that includes plate tectonics, volcanism, meteorite impacts, mountain building, and erosion, culminating in the rise of life. Recent discoveries suggest that fundamental characteristics of the present-day Ea ...
... Our home planet has reached its current state through 4.56 billion years of dynamic activity that includes plate tectonics, volcanism, meteorite impacts, mountain building, and erosion, culminating in the rise of life. Recent discoveries suggest that fundamental characteristics of the present-day Ea ...
Mantle flow, melting, and dehydration of the Iceland mantle plume
... production rates are substantially lower than predicted by models that do not include the rheological effect of dehydration. Predictions of along-axis crustal thickness, bathymetric, and gravity variations are shown to be consistent with observations at Iceland and along the Mid-Atlantic Ridge. Furt ...
... production rates are substantially lower than predicted by models that do not include the rheological effect of dehydration. Predictions of along-axis crustal thickness, bathymetric, and gravity variations are shown to be consistent with observations at Iceland and along the Mid-Atlantic Ridge. Furt ...
Active Crustal Subduction and Exhumation in Taiwan
... earthquakes beneath the central part of the island at about 24oN are too deep to be associated with a decollement or other feature related solely to crustal deformation. They suggested that these earthquakes result from an offset in the mantle lithosphere which cools the upper mantle to temperatures ...
... earthquakes beneath the central part of the island at about 24oN are too deep to be associated with a decollement or other feature related solely to crustal deformation. They suggested that these earthquakes result from an offset in the mantle lithosphere which cools the upper mantle to temperatures ...
Origins of the plume hypothesis and some of its
... I discuss plumes as thermal features to put the hypothesis in context. I start with melting temperature and melt volume as the hypothesis relates voluminous volcanism. I then discuss the flow of plume material along the base of the lithosphere with regard to Iceland and Hawaii. I discuss starting pl ...
... I discuss plumes as thermal features to put the hypothesis in context. I start with melting temperature and melt volume as the hypothesis relates voluminous volcanism. I then discuss the flow of plume material along the base of the lithosphere with regard to Iceland and Hawaii. I discuss starting pl ...
Archean Geodynamics and the Thermal Evolution of Earth
... the whole Earth, core heat flux is automatically included in the secular cooling term (the heat capacity of the core is ~1/5 of that of the entire Earth [Stacey, 1981]). In order to integrate equation (1), we need to specify both H(t) and Q(t) over the period of interest. Determining the internal he ...
... the whole Earth, core heat flux is automatically included in the secular cooling term (the heat capacity of the core is ~1/5 of that of the entire Earth [Stacey, 1981]). In order to integrate equation (1), we need to specify both H(t) and Q(t) over the period of interest. Determining the internal he ...
Constraints on flux rates and mantle dynamics beneath island arcs
... As we show here, geochemical tracers of specific sediments can be used to constrain the transport time of the subducted sediment signal and thereby provide information on convective overturn in the mantle wedge. It is generally accepted that partial melting and volcanism result from lowering of the ...
... As we show here, geochemical tracers of specific sediments can be used to constrain the transport time of the subducted sediment signal and thereby provide information on convective overturn in the mantle wedge. It is generally accepted that partial melting and volcanism result from lowering of the ...
Diamonds in Ophiolites
... It is unlikely that the carbon patches formed by transformation of diamond to graphite during decompression because this process should have produced pseudomorphs of the diamond grains, as documented in the Beni Bousera and Ronda peridotite massifs of Morocco and Spain (Davies et al. 1993), rather t ...
... It is unlikely that the carbon patches formed by transformation of diamond to graphite during decompression because this process should have produced pseudomorphs of the diamond grains, as documented in the Beni Bousera and Ronda peridotite massifs of Morocco and Spain (Davies et al. 1993), rather t ...
Thermal Structure due to Solid-State Flow in the Mantle
... with petrologic constraints. One caveat is that trajectories of melt migration beneath an arc might not be vertical. Porous flow might lead to melt migration vectors that ascend diagonally toward the wedge corner either due to pressure gradients in the mantle flow [Spiegelman and McKenzie, 1987; Phi ...
... with petrologic constraints. One caveat is that trajectories of melt migration beneath an arc might not be vertical. Porous flow might lead to melt migration vectors that ascend diagonally toward the wedge corner either due to pressure gradients in the mantle flow [Spiegelman and McKenzie, 1987; Phi ...
Unit 2 Exploring Plate Tectonics
... By measuring the ages of rocks in each chain, we know that the “bend” in the chain occurred around million years ago. Prior to that time, the Pacific plate was moving in a north-northwest direction, then abruptly (in geologic time, anyway) changed to a more west-northwest direction. Other seamoun ...
... By measuring the ages of rocks in each chain, we know that the “bend” in the chain occurred around million years ago. Prior to that time, the Pacific plate was moving in a north-northwest direction, then abruptly (in geologic time, anyway) changed to a more west-northwest direction. Other seamoun ...
Lesson Objectives Vocabulary Introduction Causes of Earthquakes
... Madrid, Missouri. This is a region not usually known for earthquakes. Because very few people lived here at the time, only 20 people died. The New Madrid Seismic Zone continues to be active (Figure below). Many more people live here today. ...
... Madrid, Missouri. This is a region not usually known for earthquakes. Because very few people lived here at the time, only 20 people died. The New Madrid Seismic Zone continues to be active (Figure below). Many more people live here today. ...
Thick-Structured Proterozoic Lithosphere of the Rocky Mountain
... In the plate margin domain, the primary grain of the image is dictated by: the high-velocity slabs associated with subduction of the Juan de Fuca plate beneath Oregon, Washington, and northern California; the evolution of the low-velocity “slab window” beneath the San Andreas transform; and the high ...
... In the plate margin domain, the primary grain of the image is dictated by: the high-velocity slabs associated with subduction of the Juan de Fuca plate beneath Oregon, Washington, and northern California; the evolution of the low-velocity “slab window” beneath the San Andreas transform; and the high ...
Plate Tectonics
... suggested a mechanism by which the continents can move. During the 1920s Alfred Wegener, a meteorologist, collected and published evidence for continental drift, but he had not been believed - partly because he could not suggest a mechanism by which the continents could move. Magnetic striping, lead ...
... suggested a mechanism by which the continents can move. During the 1920s Alfred Wegener, a meteorologist, collected and published evidence for continental drift, but he had not been believed - partly because he could not suggest a mechanism by which the continents could move. Magnetic striping, lead ...
Linking continental drift, plate tectonics and the thermal state of the
... et al. (2007, 2009) and Phillips and Coltice (2010) proposed a theory in which the evolution of the distribution of continents at the Earth’s surface causes temperature changes of 50–100 K. Geological observations support this hypothesis. For instance, the Central Atlantic Magmatic Province was empl ...
... et al. (2007, 2009) and Phillips and Coltice (2010) proposed a theory in which the evolution of the distribution of continents at the Earth’s surface causes temperature changes of 50–100 K. Geological observations support this hypothesis. For instance, the Central Atlantic Magmatic Province was empl ...
Ch 7-3 Theory Plate Tectonics
... 3. The plates can slide by in opposite directions or they may slide by in same direction, but different rates. 4. When plates move suddenly, vibrations are generated inside Earth that are felt as an earthquake. ...
... 3. The plates can slide by in opposite directions or they may slide by in same direction, but different rates. 4. When plates move suddenly, vibrations are generated inside Earth that are felt as an earthquake. ...
New Zealand`s Plates - Royal Society of New Zealand
... This type of movement is called a transform fault and it creates a distinct line in the landscape. The Alpine Fault when viewed from space is one of the longest and straightest lines on the surface of the Earth. About 10 million years ago bits of Nelson and bits of Otago were next to each other. If ...
... This type of movement is called a transform fault and it creates a distinct line in the landscape. The Alpine Fault when viewed from space is one of the longest and straightest lines on the surface of the Earth. About 10 million years ago bits of Nelson and bits of Otago were next to each other. If ...
Ch 7 - 3 Plate Tectonic
... 3. The plates can slide by in opposite directions or they may slide by in same direction, but different rates. 4. When plates move suddenly, vibrations are generated inside Earth that are felt as an earthquake. ...
... 3. The plates can slide by in opposite directions or they may slide by in same direction, but different rates. 4. When plates move suddenly, vibrations are generated inside Earth that are felt as an earthquake. ...
The role of subduction in the evolution of the Apennines foreland basin
... flexural downbending of the Adriatic plate resulting from known loads, such as topography and sediments. The unknown slab pull is inferred by constraining the model to fit the horizon that is assumed to reflect flexural downbending in two-dimensional sections perpendicular to the strike of the Apenn ...
... flexural downbending of the Adriatic plate resulting from known loads, such as topography and sediments. The unknown slab pull is inferred by constraining the model to fit the horizon that is assumed to reflect flexural downbending in two-dimensional sections perpendicular to the strike of the Apenn ...
On the origin of noble gases in mantle plumes
... Keeping any sort of chemical layering implies the existence of a stabilizing density strati cation, and preserving an undegassed abyssal layer in the deep mantle requires that primitive rocks are slightly denser than the overlying di¬erentiated material (Kellogg et al . 1999). Another point of view ...
... Keeping any sort of chemical layering implies the existence of a stabilizing density strati cation, and preserving an undegassed abyssal layer in the deep mantle requires that primitive rocks are slightly denser than the overlying di¬erentiated material (Kellogg et al . 1999). Another point of view ...
Section 1 What Are Earthquakes?
... of the 20th century, seismologists used a scale created by Charles Richter to measure the strength of earthquakes. • Earthquake Ground Motion A measure of the strength of an earthquake is called magnitude. The Richter scale measures the ground motion from an earthquake and adjusts for distance to fi ...
... of the 20th century, seismologists used a scale created by Charles Richter to measure the strength of earthquakes. • Earthquake Ground Motion A measure of the strength of an earthquake is called magnitude. The Richter scale measures the ground motion from an earthquake and adjusts for distance to fi ...
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.