- NERC Open Research Archive
... The chronologic data we present (Supplement), combined with existing published data further seaward (11), establish recessional rates of the grounding line within the main axis of the trough of ~100 m/year during the period from 12.3 to 11.7 ka. This compares favorably with ice sheet/shelf recession ...
... The chronologic data we present (Supplement), combined with existing published data further seaward (11), establish recessional rates of the grounding line within the main axis of the trough of ~100 m/year during the period from 12.3 to 11.7 ka. This compares favorably with ice sheet/shelf recession ...
Mountain building and mantle dynamics
... for propelling India in the present day [Becker and Faccenna, 2011] and rapid continental plate motions in general. However, the mantle drag amplitude will depend on the time-dependent vigor of mantle convection. [7] For orogens to be created and sustained, the sum of the acting forces such as slab ...
... for propelling India in the present day [Becker and Faccenna, 2011] and rapid continental plate motions in general. However, the mantle drag amplitude will depend on the time-dependent vigor of mantle convection. [7] For orogens to be created and sustained, the sum of the acting forces such as slab ...
Part 4 - NSW Department of Education
... of tectonic processes. Every year, news reports of volcanic eruptions and earthquakes remind us of the tectonic forces at work inside the Earth, and we can see on television some of the catastrophic effects these forces have had on local areas of the Earth’s surface. In Australia, earthquakes do occ ...
... of tectonic processes. Every year, news reports of volcanic eruptions and earthquakes remind us of the tectonic forces at work inside the Earth, and we can see on television some of the catastrophic effects these forces have had on local areas of the Earth’s surface. In Australia, earthquakes do occ ...
Poisson`s ratio in the lower mantle beneath Alaska: Evidence for
... changes in vP. Depending on the databases used, the sampling differences can be compounded by differences in quality of P and S data [e.g., Grand et al., 1997]. [5] In contrast to previous deep mantle studies of vS/vP , we do not draw inferences from global inversions but focus on a region with part ...
... changes in vP. Depending on the databases used, the sampling differences can be compounded by differences in quality of P and S data [e.g., Grand et al., 1997]. [5] In contrast to previous deep mantle studies of vS/vP , we do not draw inferences from global inversions but focus on a region with part ...
Seismic evaluation of old masonry buildings. Part I: Method
... Another disadvantage of the method is that it does not account directly for hysteretic energy dissipation. Thus, in this type of analysis, this phenomenon can only be accounted for in an approximate manner, for instance by means of changing the viscous damping coefficient, and/or by means of a behav ...
... Another disadvantage of the method is that it does not account directly for hysteretic energy dissipation. Thus, in this type of analysis, this phenomenon can only be accounted for in an approximate manner, for instance by means of changing the viscous damping coefficient, and/or by means of a behav ...
A R T I C L E S - Geoscience Research Institute
... are not at all full of sediment; and in much of the deep oceanic abyssal plains, sediment thickness averages only a few hundred meters. It would take about 50 Ma to produce the generous estimate of 435 million km3 (Ronov & Yaroshevsky 1969) of sediment now found on the ocean and continental margins. ...
... are not at all full of sediment; and in much of the deep oceanic abyssal plains, sediment thickness averages only a few hundred meters. It would take about 50 Ma to produce the generous estimate of 435 million km3 (Ronov & Yaroshevsky 1969) of sediment now found on the ocean and continental margins. ...
Depth-varying rupture properties of subduction zone megathrust faults
... source region of the 26 December 2004 Sumatra earthquake for data from (left) F-net stations in Japan and (right) broadband stations in Europe; dominant period ranges are indicated in each panel. The USGS epicenter is indicated by the white stars. Dashed contour lines indicate the trench (left-most ...
... source region of the 26 December 2004 Sumatra earthquake for data from (left) F-net stations in Japan and (right) broadband stations in Europe; dominant period ranges are indicated in each panel. The USGS epicenter is indicated by the white stars. Dashed contour lines indicate the trench (left-most ...
Upper mantle flow in the western Mediterranean
... (II), and from central France, through the Gulf of Lion, Sardinia, southern Apennines, Albania, Balkans and the Moesian platform in Bulgaria (III) (Figs. 4a and 5a). The Vs structure of the very upper mantle, in the central western Mediterranean, is obtained by non-linear inversion of surface waves ...
... (II), and from central France, through the Gulf of Lion, Sardinia, southern Apennines, Albania, Balkans and the Moesian platform in Bulgaria (III) (Figs. 4a and 5a). The Vs structure of the very upper mantle, in the central western Mediterranean, is obtained by non-linear inversion of surface waves ...
gsa today - College of Science
... the Antarctic Peninsula was located outboard of the southern end of South America (Grunow et al., 1992). Only in the Late Jurassic did the peninsula rotate away from southern South America (Lawver et al., 1992; Cunningham et al., 1995). In the vicinity of Bransfield basin, there is no direct evidenc ...
... the Antarctic Peninsula was located outboard of the southern end of South America (Grunow et al., 1992). Only in the Late Jurassic did the peninsula rotate away from southern South America (Lawver et al., 1992; Cunningham et al., 1995). In the vicinity of Bransfield basin, there is no direct evidenc ...
55. The Western Rockall Plateau
... The margins of the Rockall Plateau to the east, southwest, and west are steep and fall to depths of 2500 meters. In the north however, the margins are ill-defined and merge with the foot slopes of the seamounts surmounting the low col between the Plateau and Faeroes Platform. The western continental ...
... The margins of the Rockall Plateau to the east, southwest, and west are steep and fall to depths of 2500 meters. In the north however, the margins are ill-defined and merge with the foot slopes of the seamounts surmounting the low col between the Plateau and Faeroes Platform. The western continental ...
Deep fracture fluids isolated in the crust since the Precambrian era
... required to provide the 129Xe* observed in the fracture fluids associated with 1 m3 of Precambrian Shield rock. We note that these values are conservative and, as these processes are not well constrained, the amount of sediment required may be more than an order of magnitude less (Methods). A sedime ...
... required to provide the 129Xe* observed in the fracture fluids associated with 1 m3 of Precambrian Shield rock. We note that these values are conservative and, as these processes are not well constrained, the amount of sediment required may be more than an order of magnitude less (Methods). A sedime ...
Fault Elements and Structural Reactivation
... Slickensides occur when the rocks along a fault rub against each other, making their surfaces smoothed, lineated, and grooved. Slickenside formation may involve simple friction, or if the fault surface was once deeply buried, actual growth of oriented mineral grains may respond to the forces on the ...
... Slickensides occur when the rocks along a fault rub against each other, making their surfaces smoothed, lineated, and grooved. Slickenside formation may involve simple friction, or if the fault surface was once deeply buried, actual growth of oriented mineral grains may respond to the forces on the ...
A new method to assess long-term sea
... conjunction with sea level, water column and barometric data. to assess the long term vertical seafloor deformation to a few centimeters accuracy in shallow water environments. The method helps to remove the apparent vertical displacement on the order of tens of centimeters caused by the BPR instrum ...
... conjunction with sea level, water column and barometric data. to assess the long term vertical seafloor deformation to a few centimeters accuracy in shallow water environments. The method helps to remove the apparent vertical displacement on the order of tens of centimeters caused by the BPR instrum ...
pdf
... a low degree of decompression melting due to tectonic delocalization of deformation. Such “off-axis” magmatism might be a common process in (ultra-) slow oceanic spreading systems, where “magmatic” and “tectonic” spreading varies in both space and time. Keywords: Ocean-Continent transition, MORB, ri ...
... a low degree of decompression melting due to tectonic delocalization of deformation. Such “off-axis” magmatism might be a common process in (ultra-) slow oceanic spreading systems, where “magmatic” and “tectonic” spreading varies in both space and time. Keywords: Ocean-Continent transition, MORB, ri ...
Crustal collapse, mantle upwelling, and Cenozoic extension in the
... extensional forces arising from an overthickenedcrust are limited to the crust, while the rheology of continental lithosphereis intrinsically stratified. Even when the mantle lithosphere is mechanically coupled to the crust, thermomechanicalmodeling indicates that strain is localized in the weak low ...
... extensional forces arising from an overthickenedcrust are limited to the crust, while the rheology of continental lithosphereis intrinsically stratified. Even when the mantle lithosphere is mechanically coupled to the crust, thermomechanicalmodeling indicates that strain is localized in the weak low ...
Mantle convection in the Middle East: Reconciling Afar - HAL-Insu
... Miller and Becker (2012). We test several, geologically-motivated models of lateral viscosity variations as well as several density models to explore the effects of the different components of the AAA convection system. The goal is not so much to find the best model that matches all data at this poi ...
... Miller and Becker (2012). We test several, geologically-motivated models of lateral viscosity variations as well as several density models to explore the effects of the different components of the AAA convection system. The goal is not so much to find the best model that matches all data at this poi ...
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 ...
Global scale models of the mantle flow field predicted by synthetic
... widely used to investigate upper mantle anisotropy (e.g., Becker et al., 2003; Gaboret et al., 2003; Conrad et al., 2007); geoid undulations (e.g., Cadek and Fleitout, 1999; King and Masters, 1992); surface uplift (e.g., Gurnis et al., 2000); tectonic plate velocities (e.g., Becker and O’Connell, 20 ...
... widely used to investigate upper mantle anisotropy (e.g., Becker et al., 2003; Gaboret et al., 2003; Conrad et al., 2007); geoid undulations (e.g., Cadek and Fleitout, 1999; King and Masters, 1992); surface uplift (e.g., Gurnis et al., 2000); tectonic plate velocities (e.g., Becker and O’Connell, 20 ...
Receiver Functions of Seismic Waves in Layered Anisotropic Media
... how to calculate synthetic seismograms and receiver functions of seismic body waves propagating into a stratified anisotropic medium. Olivine and enstatite crystals, the major anisotropic minerals in peridotite (which is considered to be a candidate of upper mantle material), possess orthorhombic sy ...
... how to calculate synthetic seismograms and receiver functions of seismic body waves propagating into a stratified anisotropic medium. Olivine and enstatite crystals, the major anisotropic minerals in peridotite (which is considered to be a candidate of upper mantle material), possess orthorhombic sy ...
Evidence for Early Cretaceous oceanic crust trapped in the
... currently observed. However, the correlation of observed pro¢les with a magnetic model is nonunique because the width of the basin is less than 150 km and the number of available N^S magnetic pro¢les is therefore restricted. Moreover, although the E^W orientation of the magnetic lineations in the Hu ...
... currently observed. However, the correlation of observed pro¢les with a magnetic model is nonunique because the width of the basin is less than 150 km and the number of available N^S magnetic pro¢les is therefore restricted. Moreover, although the E^W orientation of the magnetic lineations in the Hu ...
Three distinct types of hotspots in the Earth`s mantle
... There are on the order of 40 remaining, nonprimary hotspots. These do not have enough indications of a deep, lower mantle origin in our view. We will see below that they can themselves be subdivided into two groups, one of which may have a transition zone origin whereas the other would be much more ...
... There are on the order of 40 remaining, nonprimary hotspots. These do not have enough indications of a deep, lower mantle origin in our view. We will see below that they can themselves be subdivided into two groups, one of which may have a transition zone origin whereas the other would be much more ...
From Lithospheric Thickening and Divergent Collapse to Active
... isostatic equilibrium, these four processes are implemented successively over small increments of time, a Crank-Nicholson finite differences scheme being used for the treatment of the thermal relaxation. In conjunction, a thin sheet approximation is used which considers stresses and strain rates in ...
... isostatic equilibrium, these four processes are implemented successively over small increments of time, a Crank-Nicholson finite differences scheme being used for the treatment of the thermal relaxation. In conjunction, a thin sheet approximation is used which considers stresses and strain rates in ...
Geodynamics Workshop 2012 PROGRAM AND ABSTRACTS
... Recently, it was shown [3] that a thermo-chemical plume, which contains a fraction of 10-20% of eclogitic material derived from recycled oceanic crust, explains the observations much better. Due to the high eclogite density, these thermo-chemical plumes have lower buoyancy and thus generate much sma ...
... Recently, it was shown [3] that a thermo-chemical plume, which contains a fraction of 10-20% of eclogitic material derived from recycled oceanic crust, explains the observations much better. Due to the high eclogite density, these thermo-chemical plumes have lower buoyancy and thus generate much sma ...
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... Tethyan belt. This picture disagrees with the concept, derived from hot spot studies, of an undeforming, absolute reference framework at depth, but weaknesses in current hot spot theory would make a rejection of the present model o n this ground premature. If the present model is generally correct, ...
... Tethyan belt. This picture disagrees with the concept, derived from hot spot studies, of an undeforming, absolute reference framework at depth, but weaknesses in current hot spot theory would make a rejection of the present model o n this ground premature. If the present model is generally correct, ...
Earthscope
Earthscope is an earth science program using geological and geophysical techniques to explore the structure and evolution of the North American continent and to understand the processes controlling earthquakes and volcanoes. The project has three components: USARRAY, the Plate Boundary Observatory, and the San Andreas Fault Observatory at Depth.The project is funded by the National Science Foundation (NSF), and the data produced is publicly accessible in real-time. Organizations associated with the project include UNAVCO, the Incorporated Research Institutions for Seismology (IRIS), Stanford University, the United States Geological Survey (USGS) and National Aeronautics and Space Administration (NASA). Several international organizations also contribute to the initiative.