Commentary on schematic geological map of Antarctica Scale 1:10
... Fig.24. Sheet of moraine overlying patterned ground, southern Prince Charles Mountains ...
... Fig.24. Sheet of moraine overlying patterned ground, southern Prince Charles Mountains ...
Velocity increase in the uppermost oceanic crust of subducting
... distinct later arrivals were observed during other events (e.g., events 6 and 7) of similar epicenter locations but different source depths (Figure 1c,d). The observed distinct later phases were interpreted as trapped P waves propagating along the oceanic crust of the Philippine Sea plate. To obtain ...
... distinct later arrivals were observed during other events (e.g., events 6 and 7) of similar epicenter locations but different source depths (Figure 1c,d). The observed distinct later phases were interpreted as trapped P waves propagating along the oceanic crust of the Philippine Sea plate. To obtain ...
Unraveling topography around subduction zones from
... zones more than anywhere else, have strong spatial gradients. At the surface of the Earth, the conjunction of these processes not only produces the most important deviations from the geoid (outlined by the 5-10 km deep trenches), but also the largest topographic slopes, offshore and onshore. The top ...
... zones more than anywhere else, have strong spatial gradients. At the surface of the Earth, the conjunction of these processes not only produces the most important deviations from the geoid (outlined by the 5-10 km deep trenches), but also the largest topographic slopes, offshore and onshore. The top ...
Serpentinization of the forearc mantle
... this text we use ‘water’ for H2 0, although the conditions may be such that it is a supercritical £uid. In this article we document the wide range of geological and geophysical evidence and modeling that give a consistent picture of extensive serpentinization of the forearc mantle between the trench ...
... this text we use ‘water’ for H2 0, although the conditions may be such that it is a supercritical £uid. In this article we document the wide range of geological and geophysical evidence and modeling that give a consistent picture of extensive serpentinization of the forearc mantle between the trench ...
Rhenium–osmium isotope and elemental behaviour during
... 1. Introduction Variations in the composition of the Earth's mantle are thought to reflect the processes of differentiation and recycling that have occurred throughout geological history, and this chemical heterogeneity of the mantle is sampled at the present-day by basaltic volcanism. Mid-ocean rid ...
... 1. Introduction Variations in the composition of the Earth's mantle are thought to reflect the processes of differentiation and recycling that have occurred throughout geological history, and this chemical heterogeneity of the mantle is sampled at the present-day by basaltic volcanism. Mid-ocean rid ...
Section 1 What Are Earthquakes?
... • Most earthquakes occur along tectonic plate boundaries because the movement of tectonic plates causes stress in Earth’s crust. • Earthquake energy travels through rock as seismic waves. ...
... • Most earthquakes occur along tectonic plate boundaries because the movement of tectonic plates causes stress in Earth’s crust. • Earthquake energy travels through rock as seismic waves. ...
Dynamics of the Eurasian Plate
... Bird [4] also introduces a plastic yield limit. Furthermore Lithgow-Bertelloni and Guynn [22] maintain that, by limiting the maximum harmonic degree of their fluid velocity field, they too implicitly specify a yield strength. Inevitably perhaps, given the complexity of the task, up until now all mod ...
... Bird [4] also introduces a plastic yield limit. Furthermore Lithgow-Bertelloni and Guynn [22] maintain that, by limiting the maximum harmonic degree of their fluid velocity field, they too implicitly specify a yield strength. Inevitably perhaps, given the complexity of the task, up until now all mod ...
Origin of Archean subcontinental lithospheric mantle: Some
... accompanied by orthopyroxene with about the same Mg/Fe ratios, to produce a rock with harzburgitic bulk composition (Boyd and Mertzman, 1987; Griffin et al., 1999); more rarely the rock consists only of olivine and is a highly refractory dunite (Berstein et al., 1997). Highly magnesian olivine and or ...
... accompanied by orthopyroxene with about the same Mg/Fe ratios, to produce a rock with harzburgitic bulk composition (Boyd and Mertzman, 1987; Griffin et al., 1999); more rarely the rock consists only of olivine and is a highly refractory dunite (Berstein et al., 1997). Highly magnesian olivine and or ...
Earthquakes: Basic Principles
... animals’ sense just before the occurrence of an earthquake. The occurrence of large earthquakes is often sudden, their duration is short (on the order of seconds or at most minutes) and the devastation they cause can be extensive or even total. Large earthquakes are often followed by aftershocks, wh ...
... animals’ sense just before the occurrence of an earthquake. The occurrence of large earthquakes is often sudden, their duration is short (on the order of seconds or at most minutes) and the devastation they cause can be extensive or even total. Large earthquakes are often followed by aftershocks, wh ...
High resolution image of the subducted Paci¢c (?) plate beneath
... anomalies 3^6% faster in the slab than the surrounding mantle with slow mantle velocities in the overlying mantle wedge [13], similar to other subduction zones [14]. Alaska is one of the few places undergoing active accretion of exotic terranes, a process that has continued since the Mesozoic [10]. ...
... anomalies 3^6% faster in the slab than the surrounding mantle with slow mantle velocities in the overlying mantle wedge [13], similar to other subduction zones [14]. Alaska is one of the few places undergoing active accretion of exotic terranes, a process that has continued since the Mesozoic [10]. ...
Plume heads, continental lithosphere, flood
... 1990). At 290 km depth and deeper the upper- The mesosphere, or transition region, is theremantle LV A does not follow the northern MAR gion of the mantle between the two rna jor seismic but is offset to the east, following the central At- discontinuities at 400 and 650 km depth. The lantic hotspots ...
... 1990). At 290 km depth and deeper the upper- The mesosphere, or transition region, is theremantle LV A does not follow the northern MAR gion of the mantle between the two rna jor seismic but is offset to the east, following the central At- discontinuities at 400 and 650 km depth. The lantic hotspots ...
Earthquakes: Basic Principles
... animals’ sense just before the occurrence of an earthquake. The occurrence of large earthquakes is often sudden, their duration is short (on the order of seconds or at most minutes) and the devastation they cause can be extensive or even total. Large earthquakes are often followed by aftershocks, wh ...
... animals’ sense just before the occurrence of an earthquake. The occurrence of large earthquakes is often sudden, their duration is short (on the order of seconds or at most minutes) and the devastation they cause can be extensive or even total. Large earthquakes are often followed by aftershocks, wh ...
Glencoe Earth Science
... seismograph, the drum vibrates but the pendulum remains at rest. The stationary pen traces a record of the vibrations on the moving drum of paper. The paper record of the seismic event is called a seismogram. Figure 10 shows two types of seismographs that measure either vertical or horizontal ground ...
... seismograph, the drum vibrates but the pendulum remains at rest. The stationary pen traces a record of the vibrations on the moving drum of paper. The paper record of the seismic event is called a seismogram. Figure 10 shows two types of seismographs that measure either vertical or horizontal ground ...
No Slide Title
... • Earthquakes are ground motions that result from the release of energy when blocks of rock move. • Most earthquakes occur along tectonic plate boundaries because the movement of tectonic plates causes stress in Earth’s crust. • Earthquake energy travels through rock as seismic ...
... • Earthquakes are ground motions that result from the release of energy when blocks of rock move. • Most earthquakes occur along tectonic plate boundaries because the movement of tectonic plates causes stress in Earth’s crust. • Earthquake energy travels through rock as seismic ...
Mantle hotspot neon in basalts from the Northwest Lau Back
... [8] Figure 2a shows clearly that basalts from the Northwest Lau Back-arc Basin possess a mantle neon component characterized by excesses in both 20Ne/22Ne and 21Ne/22Ne. One of our sample runs, NLD-13-3, had 20Ne/22Ne of 12.24, reflecting a high proportion of mantle neon. Our results plot roughly al ...
... [8] Figure 2a shows clearly that basalts from the Northwest Lau Back-arc Basin possess a mantle neon component characterized by excesses in both 20Ne/22Ne and 21Ne/22Ne. One of our sample runs, NLD-13-3, had 20Ne/22Ne of 12.24, reflecting a high proportion of mantle neon. Our results plot roughly al ...
Lateral Density Inhomogeneities of the Continental and Oceanic
... According to our calculations, the FMS depth in Central and Southern Asia (Fig. 3) varies within a wide range of 2–7 km, which is explained by the modern tectonic activity in the AlpineHimalayan Fold Belt and by the rifting in the northeast framing of Africa. The shallowest level of the FMS depth i ...
... According to our calculations, the FMS depth in Central and Southern Asia (Fig. 3) varies within a wide range of 2–7 km, which is explained by the modern tectonic activity in the AlpineHimalayan Fold Belt and by the rifting in the northeast framing of Africa. The shallowest level of the FMS depth i ...
Full Text
... Part of this struggle is tied to what, exactly, is supplying the strength. The strength of rocks depends on many factors including composition, temperature, pressure, stress, and grain size (e.g., Ranalli, 1995). Thus, to be a layer of strength, the lithosphere must encompass the region where these ...
... Part of this struggle is tied to what, exactly, is supplying the strength. The strength of rocks depends on many factors including composition, temperature, pressure, stress, and grain size (e.g., Ranalli, 1995). Thus, to be a layer of strength, the lithosphere must encompass the region where these ...
Petrological interpretation of deep crustal intrusive bodies beneath
... provinces reveal the presence of ultramafic bodies with P-wave velocities of Vp ~ 7.4–8.0 km/s lying at or above the Moho, e.g., Hawaii, the Marquesas, and La Reunion. However, at other hotspot provinces such as the Galapagos, Nazca Ridge, and Louisville the lower crust is intruded by large volumes o ...
... provinces reveal the presence of ultramafic bodies with P-wave velocities of Vp ~ 7.4–8.0 km/s lying at or above the Moho, e.g., Hawaii, the Marquesas, and La Reunion. However, at other hotspot provinces such as the Galapagos, Nazca Ridge, and Louisville the lower crust is intruded by large volumes o ...
pdf file - University of Victoria
... when marine fossils were found high in the mountains of Europe. How did they get there, and what lifted them up? How did they persist when erosion was recognized as an effective levelling process? There were many theories that now appear fantastic, with some quite perceptive analyses such as by the ...
... when marine fossils were found high in the mountains of Europe. How did they get there, and what lifted them up? How did they persist when erosion was recognized as an effective levelling process? There were many theories that now appear fantastic, with some quite perceptive analyses such as by the ...
OBSERVATIONAL AND THEORETICAL STUDIES OF THE DYNAMICS OF MANTLE PLUME–MID-OCEAN RIDGE INTERACTION
... only minor proportions of recycled or primitive material [e.g., Hanan and Graham, 1996], displays higher values of 21Ne/22Ne, and displays lower values of 3He/4He, with a remarkably limited range (typically 7–9 times the atmospheric ratio RA) [Kurz, 1991; Graham, 2002]. Collectively, these observati ...
... only minor proportions of recycled or primitive material [e.g., Hanan and Graham, 1996], displays higher values of 21Ne/22Ne, and displays lower values of 3He/4He, with a remarkably limited range (typically 7–9 times the atmospheric ratio RA) [Kurz, 1991; Graham, 2002]. Collectively, these observati ...
Iceland is cool: An origin for the Iceland volcanic province in the
... is a coincidence. For a mantle plume currently beneath Iceland to have been fixed relative to other Atlantic and Indian ocean hotspots, it must have migrated southeastwards at a rate of ~ 2 cm/a relative to the North American plate, from a location beneath central Greenland at ~ 60 Ma (Lawver and Mu ...
... is a coincidence. For a mantle plume currently beneath Iceland to have been fixed relative to other Atlantic and Indian ocean hotspots, it must have migrated southeastwards at a rate of ~ 2 cm/a relative to the North American plate, from a location beneath central Greenland at ~ 60 Ma (Lawver and Mu ...
Lesson-3-WSs-for-upl..
... 3. Plate boundaries occur where two tectonic plates meet. The plates can move in many different ways at the plate boundaries. Define divergent, transform, and convergent plate boundaries. ...
... 3. Plate boundaries occur where two tectonic plates meet. The plates can move in many different ways at the plate boundaries. Define divergent, transform, and convergent plate boundaries. ...
LOW RES
... orthogonal convergence rates determined using the NUVEL1A plate motion model [DeMets et al., 1994]. For the mantle wedge, we use a simple dynamical flow model of Newtonian viscous corner flow [Batchelor, 1967] driven by a no-slip boundary condition along the top of the subducting plate. Mantle-wedge ...
... orthogonal convergence rates determined using the NUVEL1A plate motion model [DeMets et al., 1994]. For the mantle wedge, we use a simple dynamical flow model of Newtonian viscous corner flow [Batchelor, 1967] driven by a no-slip boundary condition along the top of the subducting plate. Mantle-wedge ...
Thermal structure and intermediate-depth seismicity in the Tohoku
... embrittlement, shear instabilities and the presence of fluids in general, depends significantly on local conditions, including pressure, temperature and composition. The wellinstrumented and well-studied subduction zone below Northern Japan (Tohoku and Hokkaido) provides an excellent testing ground ...
... embrittlement, shear instabilities and the presence of fluids in general, depends significantly on local conditions, including pressure, temperature and composition. The wellinstrumented and well-studied subduction zone below Northern Japan (Tohoku and Hokkaido) provides an excellent testing ground ...
Mantle Exhumation in an Early Paleozoic Passive Margin, Northern
... relatively young mantle lithosphere with an age only slightly older than the Devonian metasedimentary rocks in which it is hosted or mantle that is metasomatized in the same events related to rifting. The rocks in the study area bear striking similarities to those in and surrounding the Zabargad (Re ...
... relatively young mantle lithosphere with an age only slightly older than the Devonian metasedimentary rocks in which it is hosted or mantle that is metasomatized in the same events related to rifting. The rocks in the study area bear striking similarities to those in and surrounding the Zabargad (Re ...
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.