Dynamic topography above retreating subduction zones
... Dynamic topography is implicit in the model free-air anomalies because the observed bathymetry, which is used in the calculation of model values, has dynamic topography embedded within it. Both the observed and model free-air anomalies decrease toward the center of the backarc basins. This is consis ...
... Dynamic topography is implicit in the model free-air anomalies because the observed bathymetry, which is used in the calculation of model values, has dynamic topography embedded within it. Both the observed and model free-air anomalies decrease toward the center of the backarc basins. This is consis ...
Atlantic Conjugate Margins
... • The construction of regional and global plate tectonic models is critical to understanding a wide range of geological processes such as basin dynamics, margin evolution and palaeo-environment development. • Plate models allow visualisation of regions that have undergone deformation and re-activati ...
... • The construction of regional and global plate tectonic models is critical to understanding a wide range of geological processes such as basin dynamics, margin evolution and palaeo-environment development. • Plate models allow visualisation of regions that have undergone deformation and re-activati ...
Eds. I. S. Evans, R. Dikau, E. Tokunaga, H. Ohmori... © by TERRAPUB, Tokyo, 2003.
... isostatic compensation that is on the border with astenosphere. It seems that both factors—high temperatures and dynamic prop of lithosphere plates are the result of an influence by anomalous mantle that generates intensive manifestation of magmatic processes on the ocean floor surface. Such phenome ...
... isostatic compensation that is on the border with astenosphere. It seems that both factors—high temperatures and dynamic prop of lithosphere plates are the result of an influence by anomalous mantle that generates intensive manifestation of magmatic processes on the ocean floor surface. Such phenome ...
Volcanoes Stu Notes
... i. Shield Volcanoes – a thin layers of lava pour out of a vent and harden on top of previous layers, which gradually builds a wide, gently sloping mountain. Shield volcanoes rising from a hot spot on the ocean floor created the Hawaiian Islands. ii. Cinder Cone Volcanoes – Lava has high viscosity, i ...
... i. Shield Volcanoes – a thin layers of lava pour out of a vent and harden on top of previous layers, which gradually builds a wide, gently sloping mountain. Shield volcanoes rising from a hot spot on the ocean floor created the Hawaiian Islands. ii. Cinder Cone Volcanoes – Lava has high viscosity, i ...
Alteration of the subducting oceanic lithosphere at the southern
... an empirical relationship between lithospheric age and seismic velocity. The global trend suggests that uppermost P wave velocities of layer 2 increase rapidly close to the spreading axis and within 8 Ma reach values of mature oceanic crust (>4.5 km/s) [Carlson, 1998; Grevemeyer and Bartetzko, 2004 ...
... an empirical relationship between lithospheric age and seismic velocity. The global trend suggests that uppermost P wave velocities of layer 2 increase rapidly close to the spreading axis and within 8 Ma reach values of mature oceanic crust (>4.5 km/s) [Carlson, 1998; Grevemeyer and Bartetzko, 2004 ...
Supercontinents, mantle dynamics and plate
... been challenged in recent works and current models propose that plate tectonics creates and destroys Earth's continental crust with more crust being destroyed than created. The creation–destruction balance changes over a supercontinent cycle, with a higher crustal growth through magmatic influx durin ...
... been challenged in recent works and current models propose that plate tectonics creates and destroys Earth's continental crust with more crust being destroyed than created. The creation–destruction balance changes over a supercontinent cycle, with a higher crustal growth through magmatic influx durin ...
Hawaii, Boundary Layers and Ambient
... layer (5220 km depth) of the mantle rather than by deep-seated thermal instabilities. The upper boundary layer (BL) of the mantle is fertile enough, hot enough and variable enough to provide the observed range of temperatures and compositions of mid-plate magmas, plus it is conveniently located to e ...
... layer (5220 km depth) of the mantle rather than by deep-seated thermal instabilities. The upper boundary layer (BL) of the mantle is fertile enough, hot enough and variable enough to provide the observed range of temperatures and compositions of mid-plate magmas, plus it is conveniently located to e ...
Cenozoic evolution of Neotethys and implications for the causes of
... have existed on both sides of the ocean basin, but is not preserved in the geologic record on either side of the suture zone [Berberian and King, 1981; Murris, 1980; Stocklin, 1968]. In our calculations, a minimum passive margin width of 50 km is added to both sides of the reconstructed platforms by ...
... have existed on both sides of the ocean basin, but is not preserved in the geologic record on either side of the suture zone [Berberian and King, 1981; Murris, 1980; Stocklin, 1968]. In our calculations, a minimum passive margin width of 50 km is added to both sides of the reconstructed platforms by ...
Could Iceland be a modern analogue for the Earth`s early
... Fig. 1 CIPW normative quartz – orthoclase – (anorthite + albite) – nepheline [Qz ) Or ) (An + Ab) ) Ne] diagram, showing the composition of Archaean TTG and felsic rocks from Iceland, Hawaii and Kerguelen. ...
... Fig. 1 CIPW normative quartz – orthoclase – (anorthite + albite) – nepheline [Qz ) Or ) (An + Ab) ) Ne] diagram, showing the composition of Archaean TTG and felsic rocks from Iceland, Hawaii and Kerguelen. ...
Global plume-fed asthenosphere flow
... Heard. All asthenosphere fed from these hotspots heads eastward (pushed by the excess of South-Atlantic plume supply of asthenosphere) to finally converge to the south of Australia at 110°E (Figure 5a). Kerguelen and Heard, closer to this convergence point, feed flow that goes straight through the ...
... Heard. All asthenosphere fed from these hotspots heads eastward (pushed by the excess of South-Atlantic plume supply of asthenosphere) to finally converge to the south of Australia at 110°E (Figure 5a). Kerguelen and Heard, closer to this convergence point, feed flow that goes straight through the ...
Lassen Volcanic National Park
... majority of all common volcanic rocks. Second, silica content determines what type of eruption a lava will tend to produce. Silica-rich lavas (dacites and rhyodacites) are “pasty” and tend to trap and “hold in” dissolved volatiles more effectively than runny, silica-poor ones (basalts and basaltic a ...
... majority of all common volcanic rocks. Second, silica content determines what type of eruption a lava will tend to produce. Silica-rich lavas (dacites and rhyodacites) are “pasty” and tend to trap and “hold in” dissolved volatiles more effectively than runny, silica-poor ones (basalts and basaltic a ...
How large is the subducted water flux? New constraints on mantle
... Carlo simulation to set limits on long-term global water cycling and the return flux of water to the deep Earth. Estimates of magma production rates and water contents in primary magmas generated at ocean islands, mid-ocean ridges, arcs and back-arcs are paired with estimates of water entering trench ...
... Carlo simulation to set limits on long-term global water cycling and the return flux of water to the deep Earth. Estimates of magma production rates and water contents in primary magmas generated at ocean islands, mid-ocean ridges, arcs and back-arcs are paired with estimates of water entering trench ...
Alteration of the oceanic lithosphere and its implications for seafloor
... based on early geophysical data and comparisons with ophiolites, and is commonly referred to as the “Penrose ophiolite model” or “Penrose-type crust”, defined during a Penrose conference and published in Geotimes in 1972. This model is generally applicable for crust formed at fast spreading ridges, ...
... based on early geophysical data and comparisons with ophiolites, and is commonly referred to as the “Penrose ophiolite model” or “Penrose-type crust”, defined during a Penrose conference and published in Geotimes in 1972. This model is generally applicable for crust formed at fast spreading ridges, ...
Parai and Mukhopadhyay 2012
... Carlo simulation to set limits on long-term global water cycling and the return flux of water to the deep Earth. Estimates of magma production rates and water contents in primary magmas generated at ocean islands, mid-ocean ridges, arcs and back-arcs are paired with estimates of water entering trench ...
... Carlo simulation to set limits on long-term global water cycling and the return flux of water to the deep Earth. Estimates of magma production rates and water contents in primary magmas generated at ocean islands, mid-ocean ridges, arcs and back-arcs are paired with estimates of water entering trench ...
as a PDF
... same general subduction experiment for different parameter values such as plate age is, however, debatable. It is not always clear if global or regional dynamics leads to local deviations from general trends. Section 3 reviews results from global models for the role of slabs in driving plate motions ...
... same general subduction experiment for different parameter values such as plate age is, however, debatable. It is not always clear if global or regional dynamics leads to local deviations from general trends. Section 3 reviews results from global models for the role of slabs in driving plate motions ...
view PDF
... current regional geological setting of Namibia as well as the local geology of all the settlements including Windhoek. If we consider the whole earth, it has long been recognised that the earth is divided into several plates which move against or away from one another. Today there is evidence which ...
... current regional geological setting of Namibia as well as the local geology of all the settlements including Windhoek. If we consider the whole earth, it has long been recognised that the earth is divided into several plates which move against or away from one another. Today there is evidence which ...
the seismicity of middle baikal according to local network of
... The middle part of Baikal Rift is the most important for understanding of the modern geodynamic processes between Euroasian and Amur plates. The arrangement of the epicenters of earthquakes in lake basin and strong dissociation of the axial part of the rift do not allow to identify unequivocally a t ...
... The middle part of Baikal Rift is the most important for understanding of the modern geodynamic processes between Euroasian and Amur plates. The arrangement of the epicenters of earthquakes in lake basin and strong dissociation of the axial part of the rift do not allow to identify unequivocally a t ...
How Plate-forming Processes Explain Structure and Shortening in
... carefully selected so that inferred shortening values best capture the long‐term evolution of fold and thrust belts. Such single data are provided for large‐scale cross‐sections that aim to combine years of structural analysis. Hence, shortening is not necessarily less well constrained in case of on ...
... carefully selected so that inferred shortening values best capture the long‐term evolution of fold and thrust belts. Such single data are provided for large‐scale cross‐sections that aim to combine years of structural analysis. Hence, shortening is not necessarily less well constrained in case of on ...
Seismologia ja maan rakenne 762321A Seismology and
... mantle), is broken up into tectonic plates. The Earth's lithosphere is composed of seven or eight major plates (depending on how they are defined) and many minor plates. Where the plates meet, their r ...
... mantle), is broken up into tectonic plates. The Earth's lithosphere is composed of seven or eight major plates (depending on how they are defined) and many minor plates. Where the plates meet, their r ...
Geologic Evolution of Point Lobos
... plates of the earth's crust. Plate tectonics, the term commonly used to describe the effects of this interaction, derives from heat variations within the earth's mantle. These variations are thought to drive huge convection cells within the mantle (Fig. 1). Upward-rising mantle creates large cracks ...
... plates of the earth's crust. Plate tectonics, the term commonly used to describe the effects of this interaction, derives from heat variations within the earth's mantle. These variations are thought to drive huge convection cells within the mantle (Fig. 1). Upward-rising mantle creates large cracks ...
pdf preprint - Institute of Geophysics and Planetary Physics
... not have the resolution within the lithosphere and shallow asthenosphere to distinguish between the four models proposed for the swell uplift, but surface waves studies do. The reheating and the propagating crack models cause low seismic velocities in the lower lithosphere, whereas normal velocities ...
... not have the resolution within the lithosphere and shallow asthenosphere to distinguish between the four models proposed for the swell uplift, but surface waves studies do. The reheating and the propagating crack models cause low seismic velocities in the lower lithosphere, whereas normal velocities ...
Mantle plume
A mantle plume is a mechanism proposed in 1971 to explain volcanic regions of the earth that were not thought to be explicable by the then-new theory of plate tectonics. Some such volcanic regions lie far from tectonic plate boundaries, for example, Hawaii. Others represent unusually large-volume volcanism, whether on plate boundaries, e.g. Iceland, or basalt floods such as the Deccan or Siberian traps.A mantle plume is posited to exist where hot rock nucleates at the core-mantle boundary and rises through the Earth's mantle becoming a diapir in the Earth's crust. The currently active volcanic centers are known as ""hot spots"". In particular, the concept that mantle plumes are fixed relative to one another, and anchored at the core-mantle boundary, was thought to provide a natural explanation for the time-progressive chains of older volcanoes seen extending out from some such hot spots, such as the Hawaiian–Emperor seamount chain.The hypothesis of mantle plumes from depth is not universally accepted as explaining all such volcanism. It has required progressive hypothesis-elaboration leading to variant propositions such as mini-plumes and pulsing plumes. Another hypothesis for unusual volcanic regions is the ""Plate model"". This proposes shallower, passive leakage of magma from the mantle onto the Earth's surface where extension of the lithosphere permits it, attributing most volcanism to plate tectonic processes, with volcanoes far from plate boundaries resulting from intraplate extension.