Calculating plate movement and plate motion activity File
... Finally, we'll do an interesting comparison. How well do the rates of present-day plate motion that we've measured using GPS and other surveying techniques compare with those estimated over the millions of years of geologic time? To do this, we'll look at the relative motion between North America an ...
... Finally, we'll do an interesting comparison. How well do the rates of present-day plate motion that we've measured using GPS and other surveying techniques compare with those estimated over the millions of years of geologic time? To do this, we'll look at the relative motion between North America an ...
Lamarque_Arlita_SKS_RF_GJI_201
... teleseismic events optimally. They were powered by two 80 watts solar panels connected to batteries of 500 AH to survive the polar nights between May and August. Continuous seismic signals were acquired by Guralp CMG-40 60s, three component sensors and digitized at 40 Hz by Taurus Nanometrics acquis ...
... teleseismic events optimally. They were powered by two 80 watts solar panels connected to batteries of 500 AH to survive the polar nights between May and August. Continuous seismic signals were acquired by Guralp CMG-40 60s, three component sensors and digitized at 40 Hz by Taurus Nanometrics acquis ...
Surface-wave analysis for identifying unfrozen zones in subglacial
... the subglacial sediments. Rayleigh waves, generated by the interaction of P- and S-waves at the surface of the earth, are polarized elliptically in the vertical plane containing the direction of propagation. If the elastic constants change with depth, the velocity of Rayleigh waves varies with frequ ...
... the subglacial sediments. Rayleigh waves, generated by the interaction of P- and S-waves at the surface of the earth, are polarized elliptically in the vertical plane containing the direction of propagation. If the elastic constants change with depth, the velocity of Rayleigh waves varies with frequ ...
Numerical modeling of geochemical variations caused by crustal
... for air, 1000 kg/m3 for sea water). The initial temperature field of the oceanic plate is defined by its oceanic geotherm [Turcotte and Schubert, 2002] for a specific lithospheric cooling age of 40 Myr. The initial temperature field of the continental plate increases linearly from 0 C at the surface to ...
... for air, 1000 kg/m3 for sea water). The initial temperature field of the oceanic plate is defined by its oceanic geotherm [Turcotte and Schubert, 2002] for a specific lithospheric cooling age of 40 Myr. The initial temperature field of the continental plate increases linearly from 0 C at the surface to ...
“The “plate” model for the genesis of melting anomalies”
... questioning its fundamental validity and subjecting it to rigorous tests (Foulger et al., 2005c; Foulger, 2006a). The concept of a global “hotspot” phenomenon emerged shortly after plate tectonic theory had been established (Anderson and Natland, 2005; Glen, 2005). Plate tectonics provided an elegan ...
... questioning its fundamental validity and subjecting it to rigorous tests (Foulger et al., 2005c; Foulger, 2006a). The concept of a global “hotspot” phenomenon emerged shortly after plate tectonic theory had been established (Anderson and Natland, 2005; Glen, 2005). Plate tectonics provided an elegan ...
304
... earth’s surface. Leonardo da Vinci and others during the Renaissance tried to explain the origins of landforms, and Darwin, Humboldt, J. W. Powell, and others described new landforms from around the world as part of the scientific exploration of the earth during the 16-20th centuries. Today, a diver ...
... earth’s surface. Leonardo da Vinci and others during the Renaissance tried to explain the origins of landforms, and Darwin, Humboldt, J. W. Powell, and others described new landforms from around the world as part of the scientific exploration of the earth during the 16-20th centuries. Today, a diver ...
as a PDF
... of the mantle. There is no mass balance argument that requires only the upper mantle be depleted in LIL to form the crust or that only the fertile MORB reservoir is depleted. Most of the mantle, in fact, appears depleted and there is evidence of strong upward concentration of the LIL elements. Lead ...
... of the mantle. There is no mass balance argument that requires only the upper mantle be depleted in LIL to form the crust or that only the fertile MORB reservoir is depleted. Most of the mantle, in fact, appears depleted and there is evidence of strong upward concentration of the LIL elements. Lead ...
Tethyan closure, Andean orogeny, and westward drift of the Pacific
... Pacific? Forces that arise from upper plates may have a significant impact on subduction dynamics (Royden and Husson, 2006), and for the Pacific, significant differences between the eastern- and westernbounding upper plates are evident (Table 1). Most notable among these differences is the presence of a ...
... Pacific? Forces that arise from upper plates may have a significant impact on subduction dynamics (Royden and Husson, 2006), and for the Pacific, significant differences between the eastern- and westernbounding upper plates are evident (Table 1). Most notable among these differences is the presence of a ...
Slab pull, mantle convection, and Pangaean assembly and dispersal
... The continents provide a record of global-scale mantle convection (Fig. 3). For example, the Alpine^Himalayan chain shows overall orogen-normal contraction as Africa and India migrate to the northeast and collide with Eurasia. In contrast, the North American Cordillera is characterised by protracted ...
... The continents provide a record of global-scale mantle convection (Fig. 3). For example, the Alpine^Himalayan chain shows overall orogen-normal contraction as Africa and India migrate to the northeast and collide with Eurasia. In contrast, the North American Cordillera is characterised by protracted ...
Continent-sized anomalous zones with low
... LLSVP agree with large low δVP zones that explain P-wave corephase travel times11. If some regions exhibit disagreement between lower mantle δVS and δVP structure, a mechanism that affects VP differently from VS is required to explain the disagreement, such as the post-perovskite phase transition, a ...
... LLSVP agree with large low δVP zones that explain P-wave corephase travel times11. If some regions exhibit disagreement between lower mantle δVS and δVP structure, a mechanism that affects VP differently from VS is required to explain the disagreement, such as the post-perovskite phase transition, a ...
Thermal structure of the Costa Rica – Nicaragua subduction zone
... for the mantle–wedge that focuses hot asthenosphere into the tip of the mantle–wedge. At P = 3 GPa (100 km depth), predicted slab interface temperatures are ∼800 ◦ C, about 170 ◦ C warmer than temperatures predicted using an isoviscous mantle–wedge rheology. At the same pressure, predicted temperatu ...
... for the mantle–wedge that focuses hot asthenosphere into the tip of the mantle–wedge. At P = 3 GPa (100 km depth), predicted slab interface temperatures are ∼800 ◦ C, about 170 ◦ C warmer than temperatures predicted using an isoviscous mantle–wedge rheology. At the same pressure, predicted temperatu ...
Thermal history of the Earth and its petrological expression
... used to evaluate the MgO and FeO contents of their primary magmas, which are partial melt products of the mantle. Primary magma compositions are important to constrain because their MgO and FeO contents increase with mantle potential temperature TP (Langmuir et al., 1992; Putirka, 2005; Herzberg et ...
... used to evaluate the MgO and FeO contents of their primary magmas, which are partial melt products of the mantle. Primary magma compositions are important to constrain because their MgO and FeO contents increase with mantle potential temperature TP (Langmuir et al., 1992; Putirka, 2005; Herzberg et ...
The subduction dichotomy of strong plates and weak
... geological material may have been weakened as a result. We use a computationally efficient way of parameterizing the effective viscosity that may result due to any number of mechanisms that may be active subsequent to leaving the high stress bending region, including the development of weakened tect ...
... geological material may have been weakened as a result. We use a computationally efficient way of parameterizing the effective viscosity that may result due to any number of mechanisms that may be active subsequent to leaving the high stress bending region, including the development of weakened tect ...
Insight into collision zone dynamics from topography
... generic modelling results are compared to specific observations from the Arabia-Eurasia collision zone. The study aims to illustrate that topography can be used as an indicator of the dynamics associated with continental collision and slab break-off. To a first order, the topography of the Earth’s s ...
... generic modelling results are compared to specific observations from the Arabia-Eurasia collision zone. The study aims to illustrate that topography can be used as an indicator of the dynamics associated with continental collision and slab break-off. To a first order, the topography of the Earth’s s ...
Crustal Shortening and Extension in the Central Andes: Insights
... the Andes are caused by gravitational spreading (Fig. 6) superimposed on the deformation field resulting from tectonic compression on the western boundary. Solid line (B-B’) indicates the location of velocity profile in Fig. 7. See text for the boundary conditions in (a) and (b). ...
... the Andes are caused by gravitational spreading (Fig. 6) superimposed on the deformation field resulting from tectonic compression on the western boundary. Solid line (B-B’) indicates the location of velocity profile in Fig. 7. See text for the boundary conditions in (a) and (b). ...
What controls the occurrence of shallow intraplate earthquakes? Yoshihisa Iio
... the crust is accumulated by the relative plate motion until the next interplate earthquake occurs. This stress build-up process is thought to be in accordance with the concept of the partial collision proposed by Hashimoto and Matsu’ura (2004), since a part of the relative plate motion velocity is c ...
... the crust is accumulated by the relative plate motion until the next interplate earthquake occurs. This stress build-up process is thought to be in accordance with the concept of the partial collision proposed by Hashimoto and Matsu’ura (2004), since a part of the relative plate motion velocity is c ...
Numerical lithospheric modelling: rheology, stress and deformation
... understanding the deformation of the earth's interior. Thus, investigating the rheological structure and possible consequences resulting from tectonic loading are required to some extent when interpreting geophysical data into tectonic models. In this thesis rheological structure is obtained by calc ...
... understanding the deformation of the earth's interior. Thus, investigating the rheological structure and possible consequences resulting from tectonic loading are required to some extent when interpreting geophysical data into tectonic models. In this thesis rheological structure is obtained by calc ...
Thermal and petrophysical characterization of the lithospheric
... The geometry of the crust and lithosphere mantle is not so well constrained along the Algerian basin owing to scarcity of geophysical experiments. In the northwest part of the Algerian basin the available seismic refraction profile of Hinz (1972) shows that the crust is partly oceanic with a thicknes ...
... The geometry of the crust and lithosphere mantle is not so well constrained along the Algerian basin owing to scarcity of geophysical experiments. In the northwest part of the Algerian basin the available seismic refraction profile of Hinz (1972) shows that the crust is partly oceanic with a thicknes ...
S11 NSCI 342 Packet Part A
... Note that, in this model, active upwelling of hot mantle rock is NOT the driving force for sea-floor spreading. Hot mantle rock is NOT actively pushing aside the two plates as it rises up. Rather, mantle asthenosphere passively rises at divergent plate boundaries, filling in the gap created where th ...
... Note that, in this model, active upwelling of hot mantle rock is NOT the driving force for sea-floor spreading. Hot mantle rock is NOT actively pushing aside the two plates as it rises up. Rather, mantle asthenosphere passively rises at divergent plate boundaries, filling in the gap created where th ...
File - VarsityField
... Assembly and Breakup of Pangaea The bolide impact that is hypothesized to have led to the extinction of the dinosaurs impacted the Earth’s surface __________ about __________ years ago. A. in the Australian Outback; 200 million B. in Northern Siberia; 25 million C. off the Yucatan Peninsula; 65 mil ...
... Assembly and Breakup of Pangaea The bolide impact that is hypothesized to have led to the extinction of the dinosaurs impacted the Earth’s surface __________ about __________ years ago. A. in the Australian Outback; 200 million B. in Northern Siberia; 25 million C. off the Yucatan Peninsula; 65 mil ...
and the Korea Strait
... East Sea (Japan Sea) and the Korea Strait (Tsushima Strait) for the 5–36 s period range, which is sensitive to shear wave velocities of the crust and the uppermost mantle. Images produced in our study enhance our understanding of the tectonic evolution of a continental margin affected by subducting ...
... East Sea (Japan Sea) and the Korea Strait (Tsushima Strait) for the 5–36 s period range, which is sensitive to shear wave velocities of the crust and the uppermost mantle. Images produced in our study enhance our understanding of the tectonic evolution of a continental margin affected by subducting ...
compositional and thermal differences between lithospheric and
... and its foundering into the asthenosphere. As the thickness of the lower crust increases, the mafic granulite (basalt) passes into eclogite, and density inversion occurs at the accepted crust-mantle boundary (P=20 kbar) because the newly formed eclogite is heavier than the underlying peridotite by 6 ...
... and its foundering into the asthenosphere. As the thickness of the lower crust increases, the mafic granulite (basalt) passes into eclogite, and density inversion occurs at the accepted crust-mantle boundary (P=20 kbar) because the newly formed eclogite is heavier than the underlying peridotite by 6 ...
earthquakes - New Scientist
... line (see diagram, below left). Another half-century elapsed before the plate tectonics revolution of the mid-20th century provided an explanation for the more fundamental question: what drives earthquakes? We now know that most earthquakes are caused by the build-up of stress along the planet’s act ...
... line (see diagram, below left). Another half-century elapsed before the plate tectonics revolution of the mid-20th century provided an explanation for the more fundamental question: what drives earthquakes? We now know that most earthquakes are caused by the build-up of stress along the planet’s act ...
Clutch tectonics and the partial attachment of lithospheric layers
... southern California. They find that the present velocity field of upper crustal deformation corresponds well with the long-term, average velocity field determined from geological studies and relative plate motion (also Molnar et al., 1999, for New Zealand). Therefore, they suggest that the upper cru ...
... southern California. They find that the present velocity field of upper crustal deformation corresponds well with the long-term, average velocity field determined from geological studies and relative plate motion (also Molnar et al., 1999, for New Zealand). Therefore, they suggest that the upper cru ...
Re^Os evidence for replacement of ancient mantle
... crust to convecting mantle via deep-seated processes such as foundering of dense, ma¢c lower crust (generally referred to as ‘delamination’ within the geochemical community, e.g., [7]). If the keels are absent, either because they never developed, or because they have been removed, cratons may exper ...
... crust to convecting mantle via deep-seated processes such as foundering of dense, ma¢c lower crust (generally referred to as ‘delamination’ within the geochemical community, e.g., [7]). If the keels are absent, either because they never developed, or because they have been removed, cratons may exper ...
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.