Downdip landward limit of Cascadia great earthquake rupture
... [22] The most studied and one of the strongest constraints to the rupture zone is the definition of the locked zone on the thrust fault through “back-slip” modeling [e.g., Savage, 1983] of geodetic data (GPS, repeated leveling, tide gauges, etc.). This approach is based on the approximation that the ...
... [22] The most studied and one of the strongest constraints to the rupture zone is the definition of the locked zone on the thrust fault through “back-slip” modeling [e.g., Savage, 1983] of geodetic data (GPS, repeated leveling, tide gauges, etc.). This approach is based on the approximation that the ...
1 Bathymetry of the Pacific Plate and its Implications for Thermal
... of sediments, seamounts and LIPs, using recently available datasets of high-resolution bathymetry, sediments, seamounts and LIPs. We compare the corrected topography with predictions from the HSC and plate models and examine its correlation with recent seismic models for the Pacific lithosphere and ...
... of sediments, seamounts and LIPs, using recently available datasets of high-resolution bathymetry, sediments, seamounts and LIPs. We compare the corrected topography with predictions from the HSC and plate models and examine its correlation with recent seismic models for the Pacific lithosphere and ...
TROPICS Continent-Building in Costa Rica
... differentiation may be required. At present, some new continental crust may be created at the edges of existing continents, e.g. in the Andes. This process is, however, dependent on the prior existence of continental crust, and presents a classical chicken-and-egg problem for the origin of the conti ...
... differentiation may be required. At present, some new continental crust may be created at the edges of existing continents, e.g. in the Andes. This process is, however, dependent on the prior existence of continental crust, and presents a classical chicken-and-egg problem for the origin of the conti ...
Origin and models of oceanic transform faults. Tectonophysics, 522
... Tectonic processes at mid-ocean ridges are affected by spreading rates (e.g., Buck et al., 2005; Escartin et al., 2008; Kriner et al., 2006 and references therein). In particular, the formation of oceanic detachment faults that are often associated with asymmetric accretion is well established along ...
... Tectonic processes at mid-ocean ridges are affected by spreading rates (e.g., Buck et al., 2005; Escartin et al., 2008; Kriner et al., 2006 and references therein). In particular, the formation of oceanic detachment faults that are often associated with asymmetric accretion is well established along ...
Recycling of the continental crust | SpringerLink
... Abstract--In order to understand the evolution of the crust-mantle system, it is important to recognize the role played by the recycling of continental crust. Crustal recycling can be considered as two fundamentally distinct processes: 1) intracrustal recycling and 2) crust-mantle recycling. Intracr ...
... Abstract--In order to understand the evolution of the crust-mantle system, it is important to recognize the role played by the recycling of continental crust. Crustal recycling can be considered as two fundamentally distinct processes: 1) intracrustal recycling and 2) crust-mantle recycling. Intracr ...
Ridge subduction and porphyry copper
... are considered to have formed by partial melting of continental crust [49]. In this context, it is important to note that porphyry Cu deposits are formed at shallow depths (usually <3 km). Therefore, less eroded places in supra paleosubduction zone settings, dominated by volcanic/hypabyssal suites r ...
... are considered to have formed by partial melting of continental crust [49]. In this context, it is important to note that porphyry Cu deposits are formed at shallow depths (usually <3 km). Therefore, less eroded places in supra paleosubduction zone settings, dominated by volcanic/hypabyssal suites r ...
The Patrimonial Value of the Betic Ophiolites: Rocks from the
... would later have been tectonically superimposed on the crustal rocks of the nearby continental margin, which now form the Caldera crustal unit of the Mulhacen Complex. At present the rocks of the Veleta Complex (VC) crop out forming several tectonic windows below the Mulhacen Complex (MC) (see Fig. ...
... would later have been tectonically superimposed on the crustal rocks of the nearby continental margin, which now form the Caldera crustal unit of the Mulhacen Complex. At present the rocks of the Veleta Complex (VC) crop out forming several tectonic windows below the Mulhacen Complex (MC) (see Fig. ...
Geodynpub_files/Boutelier, Chemenda, 2011
... are the normal and tangential stresses generated by the subduction process. Since the interplate friction appears generally small for oceanic subduction zones (Tichelaar and Ruff 1993; Peacock 1996; Hassani et al. 1997), the normal stress (interplate pressure) is the main parameter controlling the s ...
... are the normal and tangential stresses generated by the subduction process. Since the interplate friction appears generally small for oceanic subduction zones (Tichelaar and Ruff 1993; Peacock 1996; Hassani et al. 1997), the normal stress (interplate pressure) is the main parameter controlling the s ...
Consulta: creatorFacets:"Mascle, Jean" Registros recuperados: 28
... Submarine hydrocarbon seeps are geologically driven "hotspots" of increased biological activity on the seabed. As part of the HERMES project, several sites of natural hydrocarbon seepage in the European seas were investigated in detail, including mud volcanoes and pockmarks, in study areas extending ...
... Submarine hydrocarbon seeps are geologically driven "hotspots" of increased biological activity on the seabed. As part of the HERMES project, several sites of natural hydrocarbon seepage in the European seas were investigated in detail, including mud volcanoes and pockmarks, in study areas extending ...
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 ...
How do subduction processes contribute to forearc - HAL-Insu
... (~37.5°S) does not correspond to any subducting ridge. Melnick et al. (2009) show this uplift may result from N-S continental shortening resulting from the Northward motion of the Chiloe forearc sliver. In fact, it has been noted that peninsulas generally correspond to particular places in which cru ...
... (~37.5°S) does not correspond to any subducting ridge. Melnick et al. (2009) show this uplift may result from N-S continental shortening resulting from the Northward motion of the Chiloe forearc sliver. In fact, it has been noted that peninsulas generally correspond to particular places in which cru ...
What moves slabs - Dipartimento di Scienze della Terra
... 2002; Bercovici, 2003), and plate motions energized by top-driven mantle convection, in which the negative buoyancy of the slab, i.e., the slab pull, drives plates (e.g., Anderson, 2001). However, we discuss these models suggesting they are both far from explaining the surface geology and kinematics ...
... 2002; Bercovici, 2003), and plate motions energized by top-driven mantle convection, in which the negative buoyancy of the slab, i.e., the slab pull, drives plates (e.g., Anderson, 2001). However, we discuss these models suggesting they are both far from explaining the surface geology and kinematics ...
Chromium isotope fractionation during subduction
... move forward our understanding of (1) the Earth's high temperature Cr isotope inventory and (2) Cr isotope fractionations during subduction-related metamorphism, black shale weathering and hydrothermal alteration. The examined basalts and their metamorphosed equivalents yielded δ53Cr values falling ...
... move forward our understanding of (1) the Earth's high temperature Cr isotope inventory and (2) Cr isotope fractionations during subduction-related metamorphism, black shale weathering and hydrothermal alteration. The examined basalts and their metamorphosed equivalents yielded δ53Cr values falling ...
Crustal growth at active continental margins: Numerical
... is pushed toward an either fixed or moving continental plate (1500 km) reproducing a collision zone. The rectangular grid with 2041 201 nodes is non-uniform, resulting in a high resolution (1 km 1 km) area in the center of the model covering 1500 km horizontally, while the rest of the model remai ...
... is pushed toward an either fixed or moving continental plate (1500 km) reproducing a collision zone. The rectangular grid with 2041 201 nodes is non-uniform, resulting in a high resolution (1 km 1 km) area in the center of the model covering 1500 km horizontally, while the rest of the model remai ...
Deep ocean ventilation, carbon isotopes, marine sedimentation and
... Reconstructions of the glacial δ 13 C distribution from benthic foraminifera in the Pacific Ocean show that – relative to the Holocene – deep water below 2000–2500 m was more depleted in δ 13 C compared to the upper water mass (Matsumoto et al., 2002; Keigwin, 1998). In the Indian, Atlantic and Sout ...
... Reconstructions of the glacial δ 13 C distribution from benthic foraminifera in the Pacific Ocean show that – relative to the Holocene – deep water below 2000–2500 m was more depleted in δ 13 C compared to the upper water mass (Matsumoto et al., 2002; Keigwin, 1998). In the Indian, Atlantic and Sout ...
inferences on potential seamount locations from
... Our study has found a relatively simple way of extrapolating potential seamounts from mid-resolution bathymetric data. Although there is no reference to volcanism, the requirement for finding large undersea peaked features (potential seamounts) was fulfilled. The criteria for the extrapolation was o ...
... Our study has found a relatively simple way of extrapolating potential seamounts from mid-resolution bathymetric data. Although there is no reference to volcanism, the requirement for finding large undersea peaked features (potential seamounts) was fulfilled. The criteria for the extrapolation was o ...
Formation and Exhumation of Ultrahigh
... The earliest models for UHP tectonism assumed that it occurs during subduction of a continental margin because the metamorphic pressure–temperature (P–T) conditions of UHP rocks are typical of subduction zones and not of overthickened continental collision zones, such as the Tibetan Plateau. A secon ...
... The earliest models for UHP tectonism assumed that it occurs during subduction of a continental margin because the metamorphic pressure–temperature (P–T) conditions of UHP rocks are typical of subduction zones and not of overthickened continental collision zones, such as the Tibetan Plateau. A secon ...
Winter et al 1997b
... isotope compositions. Whereas strontium and lead isotope compositions are relatively invariant from ~ 5 to 1.7 Ma, end values start to increase at ~ 3 Ma. Subsequently, S7Sr/86Sr and 2°6pb/z°4Pb ratios progressively increase and end values progressively decrease from ~ 1.7 Ma to the present day. Fro ...
... isotope compositions. Whereas strontium and lead isotope compositions are relatively invariant from ~ 5 to 1.7 Ma, end values start to increase at ~ 3 Ma. Subsequently, S7Sr/86Sr and 2°6pb/z°4Pb ratios progressively increase and end values progressively decrease from ~ 1.7 Ma to the present day. Fro ...
Behavior of subducting sediments beneath an arc under a high
... has demonstrated that a high temperature condition required for sediment melting can be developed beneath the Setouchi area (Furukawa and Tatsumi, 1999); and (3) The Setouchi HMAs and basalt can coexist with mantle peridotite (Tatsumi, 1982). Although the mixing process of the mantle peridotite with ...
... has demonstrated that a high temperature condition required for sediment melting can be developed beneath the Setouchi area (Furukawa and Tatsumi, 1999); and (3) The Setouchi HMAs and basalt can coexist with mantle peridotite (Tatsumi, 1982). Although the mixing process of the mantle peridotite with ...
Crust and upper mantle structure beneath the Pacific Northwest from
... Figure 1. Map of the geologic and tectonic setting of the Pacific Northwest. Brown shaded region indicates the area covered by the Columbia River and Steens flood basalts (CRSB). Red triangles indicate Holocene volcanoes. Solid white lines are state boundaries. The dashed red line is the 87Sr/86Sr = ...
... Figure 1. Map of the geologic and tectonic setting of the Pacific Northwest. Brown shaded region indicates the area covered by the Columbia River and Steens flood basalts (CRSB). Red triangles indicate Holocene volcanoes. Solid white lines are state boundaries. The dashed red line is the 87Sr/86Sr = ...
A global seamount classification to aid the scientific design of
... 2.1.3. Allocation of biogeographic region Faunal composition varies throughout large areas of the worlds’ oceans, for a variety of reasons including historical as well as present day processes. This variation should be recognised before any sub-division based solely on physical factors occurs. Bioge ...
... 2.1.3. Allocation of biogeographic region Faunal composition varies throughout large areas of the worlds’ oceans, for a variety of reasons including historical as well as present day processes. This variation should be recognised before any sub-division based solely on physical factors occurs. Bioge ...
How do subduction processes contribute to forearc Andean uplift
... 1. Coastal uplift along the South American active margin Long-term uplift is visible along large segments of the Pacific coasts of South America. Pédoja et al. (2011) review the evidence of coastal uplift since the last interglacial stage, 122 kyrs ago (Marine isotopic Stage 5e). They note that along ...
... 1. Coastal uplift along the South American active margin Long-term uplift is visible along large segments of the Pacific coasts of South America. Pédoja et al. (2011) review the evidence of coastal uplift since the last interglacial stage, 122 kyrs ago (Marine isotopic Stage 5e). They note that along ...
Environmental Management of Deep
... I.1 Attributes of vents and seeps Both vent and seep ecosystems are fueled primarily by microbial primary production through a process known as chemosynthesis. Instead of using energy from sunlight to fix inorganic carbon into organic carbon (photosynthesis), microbes in vent and seep ecosystems use ...
... I.1 Attributes of vents and seeps Both vent and seep ecosystems are fueled primarily by microbial primary production through a process known as chemosynthesis. Instead of using energy from sunlight to fix inorganic carbon into organic carbon (photosynthesis), microbes in vent and seep ecosystems use ...
Radiogenic Isotope Geochemistry of the Mantle
... of melting of the mantle. Mid-ocean ridge basalts are simply those lavas erupted at mid-ocean ridge spreading centers, i.e., divergent plate boundaries. ...
... of melting of the mantle. Mid-ocean ridge basalts are simply those lavas erupted at mid-ocean ridge spreading centers, i.e., divergent plate boundaries. ...
On the total geostrophic circulation of the North Atlantic Ocean: Flow
... The maps of temperature and salinity at the surface from these data (Figs. 4a-b) axe not significantly different from other versions. The highest density of the surface layer of the open Atlantic is about 27.78 in tro, found just offshore of Greenland in the Labrador and Irminger basins, along the a ...
... The maps of temperature and salinity at the surface from these data (Figs. 4a-b) axe not significantly different from other versions. The highest density of the surface layer of the open Atlantic is about 27.78 in tro, found just offshore of Greenland in the Labrador and Irminger basins, along the a ...
Abyssal plain
An abyssal plain is an underwater plain on the deep ocean floor, usually found at depths between 3000 and 6000 m. Lying generally between the foot of a continental rise and a mid-ocean ridge, abyssal plains cover more than 50% of the Earth’s surface. They are among the flattest, smoothest and least explored regions on Earth. Abyssal plains are key geologic elements of oceanic basins (the other elements being an elevated mid-ocean ridge and flanking abyssal hills). In addition to these elements, active oceanic basins (those that are associated with a moving plate tectonic boundary) also typically include an oceanic trench and a subduction zone.Abyssal plains were not recognized as distinct physiographic features of the sea floor until the late 1940s and, until very recently, none had been studied on a systematic basis. They are poorly preserved in the sedimentary record, because they tend to be consumed by the subduction process. The creation of the abyssal plain is the end result of spreading of the seafloor (plate tectonics) and melting of the lower oceanic crust. Magma rises from above the asthenosphere (a layer of the upper mantle) and as this basaltic material reaches the surface at mid-ocean ridges it forms new oceanic crust. This is constantly pulled sideways by spreading of the seafloor. Abyssal plains result from the blanketing of an originally uneven surface of oceanic crust by fine-grained sediments, mainly clay and silt. Much of this sediment is deposited by turbidity currents that have been channelled from the continental margins along submarine canyons down into deeper water. The remainder of the sediment is composed chiefly of pelagic sediments. Metallic nodules are common in some areas of the plains, with varying concentrations of metals, including manganese, iron, nickel, cobalt, and copper. These nodules may provide a significant resource for future mining ventures.Owing in part to their vast size, abyssal plains are currently believed to be a major reservoir of biodiversity. The abyss also exerts significant influence upon ocean carbon cycling, dissolution of calcium carbonate, and atmospheric CO2 concentrations over timescales of 100–1000 years. The structure and function of abyssal ecosystems are strongly influenced by the rate of flux of food to the seafloor and the composition of the material that settles. Factors such as climate change, fishing practices, and ocean fertilization are expected to have a substantial effect on patterns of primary production in the euphotic zone. This will undoubtedly impact the flux of organic material to the abyss in a similar manner and thus have a profound effect on the structure, function and diversity of abyssal ecosystems.