Non-hotspot volcano chains from small
... with low He/heat flux ratios in the proximity of mid-ocean ridges which required a lower, undegassed mantle from which He removal would be impeded. Such low flux ratios were thought to result from a He deficit in the original upper mantle reservoir based on the assumption that both He and heat are i ...
... with low He/heat flux ratios in the proximity of mid-ocean ridges which required a lower, undegassed mantle from which He removal would be impeded. Such low flux ratios were thought to result from a He deficit in the original upper mantle reservoir based on the assumption that both He and heat are i ...
essentials-of-oceanography-10th-edition-trujillo-test
... A) continental drift. B) density. C) isostasy. D) ophiolites. E) paleomagnetism. Answer: C Diff: 2 Skill: comprehension 44) Which of the following statements is true of the asthenosphere? A) The asthenosphere is composed of continental and oceanic plates. B) The asthenosphere is composed of outer ma ...
... A) continental drift. B) density. C) isostasy. D) ophiolites. E) paleomagnetism. Answer: C Diff: 2 Skill: comprehension 44) Which of the following statements is true of the asthenosphere? A) The asthenosphere is composed of continental and oceanic plates. B) The asthenosphere is composed of outer ma ...
PNAS-2014-Anderson-1..
... detail, they also violate the first and second laws of thermodynamics because they require noncooling boundaries and external sources of energy, material, and information (e.g., Maxwell demons); that is, the model planets are not closed, isolated, selforganizing systems living off of their own resou ...
... detail, they also violate the first and second laws of thermodynamics because they require noncooling boundaries and external sources of energy, material, and information (e.g., Maxwell demons); that is, the model planets are not closed, isolated, selforganizing systems living off of their own resou ...
Global Tectonics - dynamicearth.de
... These authors concluded that for a steadily (exponentially) cooling Earth, plate tectonics is capable of removing all the required heat at a plate tectonic rate comparable to or lower than the current rate of operation. This result is contrary to the notion that faster spreading would be required in ...
... These authors concluded that for a steadily (exponentially) cooling Earth, plate tectonics is capable of removing all the required heat at a plate tectonic rate comparable to or lower than the current rate of operation. This result is contrary to the notion that faster spreading would be required in ...
Lithospheric Layering in the North American Craton
... and higher resolution than previously obtained, the crustal thickness and the depth to the Moho and lithosphere-asthenosphere boundary (LAB) throughout the Western U.S. Individual receiver functions have been converted to depth and laterally “migrated” to their conversion point using 3D P- and S-wav ...
... and higher resolution than previously obtained, the crustal thickness and the depth to the Moho and lithosphere-asthenosphere boundary (LAB) throughout the Western U.S. Individual receiver functions have been converted to depth and laterally “migrated” to their conversion point using 3D P- and S-wav ...
Tectonically asymmetric Earth - Dipartimento di Scienze della Terra
... there are plates such as Africa or Eurasia that move without slabs in their direction of motion and, in these cases, the trench suction model does not apply. Cenozoic magnetic anomalies and the trend of subduction zones indicate that plates follow globally coherent trajectories (Doglioni, 1990). Dev ...
... there are plates such as Africa or Eurasia that move without slabs in their direction of motion and, in these cases, the trench suction model does not apply. Cenozoic magnetic anomalies and the trend of subduction zones indicate that plates follow globally coherent trajectories (Doglioni, 1990). Dev ...
Teacher Resouces Booklet - CIOSS
... length, depending on the temperature of the subducted oceanic plate, which heats up as it is pushed deeper beneath the continent. As it becomes hotter and more molten, it eventually loses the ability to store mechanical stress and generates earthquakes. The Cascadia subduction zone can produce very ...
... length, depending on the temperature of the subducted oceanic plate, which heats up as it is pushed deeper beneath the continent. As it becomes hotter and more molten, it eventually loses the ability to store mechanical stress and generates earthquakes. The Cascadia subduction zone can produce very ...
mid-ocean ridges: mantle convection
... Figure 2 (a) Global average (dots) seafloor depth (after correcting for sedimentation) and standard deviations (light curve) increase with seafloor age. Dashed curve is predicted by assuming that the lithosphere cools and thickens indefinitely, as if it overlies an infinite half space. Solid curve a ...
... Figure 2 (a) Global average (dots) seafloor depth (after correcting for sedimentation) and standard deviations (light curve) increase with seafloor age. Dashed curve is predicted by assuming that the lithosphere cools and thickens indefinitely, as if it overlies an infinite half space. Solid curve a ...
Seismic characteristics and distribution of volcanic
... Abstract: A voluminous magmatic complex was emplaced in the Vøring and Møre basins during Paleocene/Eocene continental rifting and break-up in the NE Atlantic. This intrusive event has had a significant impact on deformation, source-rock maturation and fluid flow in the basins. Intrusive complexes a ...
... Abstract: A voluminous magmatic complex was emplaced in the Vøring and Møre basins during Paleocene/Eocene continental rifting and break-up in the NE Atlantic. This intrusive event has had a significant impact on deformation, source-rock maturation and fluid flow in the basins. Intrusive complexes a ...
What controls the occurrence of shallow intraplate earthquakes? Yoshihisa Iio
... The total force acting in the intraplate crust is decreased by the earthquake slip. Then, the crust is shortened to compensate for this decrease of the total force, and the stress in the crust is accumulated by the relative plate motion until the next interplate earthquake occurs. This stress build- ...
... The total force acting in the intraplate crust is decreased by the earthquake slip. Then, the crust is shortened to compensate for this decrease of the total force, and the stress in the crust is accumulated by the relative plate motion until the next interplate earthquake occurs. This stress build- ...
Geological Evidence For The Geographical Pattern of Mantle Return
... ridges,so that deep-mantleupweilingsneed not be centeredunder spreadingridgesand therefore are not required to move laterally to follow ridge migrations. The analysisup to this point suggests that upper mantle return flow is a responseto the motion of the continents. The secondpart of the paper sugg ...
... ridges,so that deep-mantleupweilingsneed not be centeredunder spreadingridgesand therefore are not required to move laterally to follow ridge migrations. The analysisup to this point suggests that upper mantle return flow is a responseto the motion of the continents. The secondpart of the paper sugg ...
(PDF 8mb)
... 2) The seismicity lineaments/zones relieve most of their strain accumulation in small earthquakes, and thus do not produce significant surface-rupturing earthquakes 3) The faults that do produce large surface-rupturing earthquakes do have background seismicity, but much of it is below the detection ...
... 2) The seismicity lineaments/zones relieve most of their strain accumulation in small earthquakes, and thus do not produce significant surface-rupturing earthquakes 3) The faults that do produce large surface-rupturing earthquakes do have background seismicity, but much of it is below the detection ...
Convergent plate margin dynamics
... (Dietz, 1961; Hess, 1962) proposed the concept of seafloor spreading, which stated that seafloor comes into being at mid-oceanic ridges to fill the cracks or voids that are being created by the surrounding seafloor that is moving away in opposite directions on either side of the ocean ridge. This model ...
... (Dietz, 1961; Hess, 1962) proposed the concept of seafloor spreading, which stated that seafloor comes into being at mid-oceanic ridges to fill the cracks or voids that are being created by the surrounding seafloor that is moving away in opposite directions on either side of the ocean ridge. This model ...
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... and the Driving Mechanism of Plate Tectonics Department of Geology a n d Geopbsics, University of California, Berkeley, California 94720 Tectonic features at the earth's surface can be used to test models for mantle return flow and to determine the geographic pattern of this flow. A model with shall ...
... and the Driving Mechanism of Plate Tectonics Department of Geology a n d Geopbsics, University of California, Berkeley, California 94720 Tectonic features at the earth's surface can be used to test models for mantle return flow and to determine the geographic pattern of this flow. A model with shall ...
Whole-mantle convection and plate tectonics
... ‘return’ flow is entirely contained in the lower, more viscous layer: its much higher viscosity is compensated by its greater thickness. Also, as Takeuchi & Sakata pointed out, the width of the cell which is the least stable to the adverse temperature gradient is still about the same as the total de ...
... ‘return’ flow is entirely contained in the lower, more viscous layer: its much higher viscosity is compensated by its greater thickness. Also, as Takeuchi & Sakata pointed out, the width of the cell which is the least stable to the adverse temperature gradient is still about the same as the total de ...
Crust–mantle boundaries in the Taiwan–Luzon arc
... dips to the east under southeastern Taiwan and steepens progressively towards north until it becomes vertical at 23.7°N. From there it continues northward in a vertical orientation, until the limit of the tomographic model inhibited further mapping. For the Moho, additional depth constraints were de ...
... dips to the east under southeastern Taiwan and steepens progressively towards north until it becomes vertical at 23.7°N. From there it continues northward in a vertical orientation, until the limit of the tomographic model inhibited further mapping. For the Moho, additional depth constraints were de ...
Continental Margin Deformation along the Andean Subduction zone
... chosen this time span because (1) it represents well the order of magnitude of typical discrete deformation events affecting active continental margins (which however, superimpose on regional features resulting from firstorder kinematic and rheological parameters that ...
... chosen this time span because (1) it represents well the order of magnitude of typical discrete deformation events affecting active continental margins (which however, superimpose on regional features resulting from firstorder kinematic and rheological parameters that ...
View/Open - Earth
... of 1040 kg/m3), unconsolidated sediments (density of 1900 kg/m3), evaporites (density 2200 kg/m3) and a 5 km constant thickness crust (density of 2670 kg/m3) limited by and parallel to the base of the evaporites. Grids of bathymetry and sediment thickness were produced at 0.15 km of spatial resolut ...
... of 1040 kg/m3), unconsolidated sediments (density of 1900 kg/m3), evaporites (density 2200 kg/m3) and a 5 km constant thickness crust (density of 2670 kg/m3) limited by and parallel to the base of the evaporites. Grids of bathymetry and sediment thickness were produced at 0.15 km of spatial resolut ...
A detailed study of the Gagua Ridge: A fracture zone uplifted during
... to belong rather to the Luzon Volcanic Arc, except for the gabbro samples which may come from the Gagua Ridge. Another dredge, which was made on the west flank of the ridge (at 21◦290 N, far from the Luzon Arc), reveals gabbros, and no other rocks like an- ...
... to belong rather to the Luzon Volcanic Arc, except for the gabbro samples which may come from the Gagua Ridge. Another dredge, which was made on the west flank of the ridge (at 21◦290 N, far from the Luzon Arc), reveals gabbros, and no other rocks like an- ...
Initiation of subduction in nature and models
... later due to the cooling and thickening of the lithosphere along the margin wand. This sequence of events explains why mature passive margins are typically very stable [4]. The issue of induced versus spontaneous subduction initiation also remains partially controversial in both nature and within n ...
... later due to the cooling and thickening of the lithosphere along the margin wand. This sequence of events explains why mature passive margins are typically very stable [4]. The issue of induced versus spontaneous subduction initiation also remains partially controversial in both nature and within n ...
G. Heinson, Electromagnetic studies of the lithosphere and
... solid-state convective motions of the upper mantle over long time-scales. The models in Figure 2 show that the most seismically-heterogeneous region of the upper mantle is within the top 100 km. Low-velocity zones are centred over the mid-ocean ridges, particularly evident across the East Pacific Ri ...
... solid-state convective motions of the upper mantle over long time-scales. The models in Figure 2 show that the most seismically-heterogeneous region of the upper mantle is within the top 100 km. Low-velocity zones are centred over the mid-ocean ridges, particularly evident across the East Pacific Ri ...
Sub-slab mantle flow parallel to the Caribbean plate boundaries
... Upper-mantle deformation near the margins of the Caribbean plate is investigated using observations of shear-wave splitting in teleseismic and local shear phases. The Caribbean plate is almost stationary in the hot-spot reference frame and is wedged between the North America, South America, Nazca an ...
... Upper-mantle deformation near the margins of the Caribbean plate is investigated using observations of shear-wave splitting in teleseismic and local shear phases. The Caribbean plate is almost stationary in the hot-spot reference frame and is wedged between the North America, South America, Nazca an ...
Mantle flow in regions of complex tectonics: Insights from Indonesia
... perhaps most tectonically stable region in the study area today, as there is currently no active subduction around the island and, hence, little seismicity compared to the rest of Indonesia. The mid-Eocene (45 Ma ago), however, saw the onset of subduction of the Proto-South China Sea in the Sarawak ...
... perhaps most tectonically stable region in the study area today, as there is currently no active subduction around the island and, hence, little seismicity compared to the rest of Indonesia. The mid-Eocene (45 Ma ago), however, saw the onset of subduction of the Proto-South China Sea in the Sarawak ...
2. Geology and tectonics of the Aegean - diss.fu
... 1978). It is not older than 2 My, it opens at about 1 cm/yr and accommodates a large part of the extensional deformation (Armijo et al., 1996; Hatzfeld et al., 1996). It is suggested that this detachment is due to the uncoupling of the brittle upper crust from a more ductile lower crust (Melis et al ...
... 1978). It is not older than 2 My, it opens at about 1 cm/yr and accommodates a large part of the extensional deformation (Armijo et al., 1996; Hatzfeld et al., 1996). It is suggested that this detachment is due to the uncoupling of the brittle upper crust from a more ductile lower crust (Melis et al ...