Arthur Holmes` paper of 1929 on convection currents within the
... episodic eruptions of plateau basalts and orogenies. Subsequently (Joly, 1924, 1925) argued that the Earth could not be cooling as Lord Kelvin had supposed in the nineteenth century. On the contrary, it was constantly generating subterranean heat, which was discharged from time to time. The heat gen ...
... episodic eruptions of plateau basalts and orogenies. Subsequently (Joly, 1924, 1925) argued that the Earth could not be cooling as Lord Kelvin had supposed in the nineteenth century. On the contrary, it was constantly generating subterranean heat, which was discharged from time to time. The heat gen ...
Escape tectonics and the extrusion of Alaska: Past, present, and future
... From a stable Canadian Cordillera (landward of the Tintina fault system) reference frame, northward translation of crustal slivers of North America along the British Columbia margin drives terrane fragments into the apex of the Alaskan restraining bend. Crust then escapes westward toward the Aleutia ...
... From a stable Canadian Cordillera (landward of the Tintina fault system) reference frame, northward translation of crustal slivers of North America along the British Columbia margin drives terrane fragments into the apex of the Alaskan restraining bend. Crust then escapes westward toward the Aleutia ...
Geol Soc London Spec Publ 204 2002
... fluids circulating through the Earths crust concentrate an element, or elements, in a particular location. Sufficient concentration of the ore to create an economic body relies on an appropriate balance between several variables. The lifetime of the system, the chemical environment provided by the ...
... fluids circulating through the Earths crust concentrate an element, or elements, in a particular location. Sufficient concentration of the ore to create an economic body relies on an appropriate balance between several variables. The lifetime of the system, the chemical environment provided by the ...
Chapter 36C. North Pacific Ocean
... The Pacific is the largest division of the World Ocean, at over 165 million km2, extending from the Arctic Ocean in the north to the Southern Ocean in the south (Figure 1). Along the western margin are several seas. The Strait of Malacca joins the Pacific and the Indian Oceans to the west, and the D ...
... The Pacific is the largest division of the World Ocean, at over 165 million km2, extending from the Arctic Ocean in the north to the Southern Ocean in the south (Figure 1). Along the western margin are several seas. The Strait of Malacca joins the Pacific and the Indian Oceans to the west, and the D ...
Evidence for strong sediment redistribution by bottom currents along
... #ow seems to occur at depths of around 4000 m in the northern sector of the SIB, as inferred from sea beds of Mn pavement to abundant nodules (Kennett and Watkins, 1975, 1976). This strong eastward #ow of AABW may be enhanced by the addition of high-velocity ACC that is concentrated along the northe ...
... #ow seems to occur at depths of around 4000 m in the northern sector of the SIB, as inferred from sea beds of Mn pavement to abundant nodules (Kennett and Watkins, 1975, 1976). This strong eastward #ow of AABW may be enhanced by the addition of high-velocity ACC that is concentrated along the northe ...
Deep-sea fisheries and vulnerable ecosystems in the northeast
... 3 Regulate the catch of all deep-sea species—including bycatch—for sustainability (Articles 4 and 10). 4 Strengthen the definition of ‘most vulnerable species’ and add measures to minimise or prevent the catch of vulnerable, threatened, or endangered species in deepsea fisheries. 5 Require that c ...
... 3 Regulate the catch of all deep-sea species—including bycatch—for sustainability (Articles 4 and 10). 4 Strengthen the definition of ‘most vulnerable species’ and add measures to minimise or prevent the catch of vulnerable, threatened, or endangered species in deepsea fisheries. 5 Require that c ...
Deep-sea fisheries and vulnerable ecosystems in the northeast
... 3 Regulate the catch of all deep-sea species—including bycatch—for sustainability (Articles 4 and 10). 4 Strengthen the definition of ‘most vulnerable species’ and add measures to minimise or prevent the catch of vulnerable, threatened, or endangered species in deepsea fisheries. 5 Require that c ...
... 3 Regulate the catch of all deep-sea species—including bycatch—for sustainability (Articles 4 and 10). 4 Strengthen the definition of ‘most vulnerable species’ and add measures to minimise or prevent the catch of vulnerable, threatened, or endangered species in deepsea fisheries. 5 Require that c ...
Introduction To Marine Biology
... • Neritic zone: • It is extending from low tide mark to the edge of the continental shelf. • Characters of Neritic zone: • Shallow depth ≈ 200 meters. • well-oxygenated water • Low water pressure. • Stable temperature and salinity levels. • High photosynthetic activities from phytoplankton and floa ...
... • Neritic zone: • It is extending from low tide mark to the edge of the continental shelf. • Characters of Neritic zone: • Shallow depth ≈ 200 meters. • well-oxygenated water • Low water pressure. • Stable temperature and salinity levels. • High photosynthetic activities from phytoplankton and floa ...
The viability and style of the modern plate
... subduction below an 5-cm/yr overriding plate is followed by a sudden drop in vconv and vrms , as a result of the removed overriding plate motion. Subduction then slowly develops until the slab reaches 400 km depth, and the subduction is reinforced by the extra phase buoyancy of the exothermic olivin ...
... subduction below an 5-cm/yr overriding plate is followed by a sudden drop in vconv and vrms , as a result of the removed overriding plate motion. Subduction then slowly develops until the slab reaches 400 km depth, and the subduction is reinforced by the extra phase buoyancy of the exothermic olivin ...
Negredo et al. Pamir subduction, EPSL, 259, 2007
... relocated about 6000 shallow and intermediate-depth earthquakes in this area during the period 1964–1992 and provided a more detailed knowledge of the geometry of the seismic zone. They confirmed the earlier picture of a 700-km-long S-shaped seismic zone, and obtained that its width is generally les ...
... relocated about 6000 shallow and intermediate-depth earthquakes in this area during the period 1964–1992 and provided a more detailed knowledge of the geometry of the seismic zone. They confirmed the earlier picture of a 700-km-long S-shaped seismic zone, and obtained that its width is generally les ...
It snows in the middle of the Pacific on the summit of this volcanic
... No point on the planet reaches higher into the atmosphere than Mount Everest: 29,035 feet. But as a geologic formation, it is substantially smaller than Mauna Kea. Everest begins its rise in the Himalaya at an average elevation of 19,160 feet above sea level. Its height from base to summit averages ...
... No point on the planet reaches higher into the atmosphere than Mount Everest: 29,035 feet. But as a geologic formation, it is substantially smaller than Mauna Kea. Everest begins its rise in the Himalaya at an average elevation of 19,160 feet above sea level. Its height from base to summit averages ...
Plate Tectonics - cloudfront.net
... —the ground you sit on is moving! Just as Copernicus, Kepler, and Galileo had trouble convincing people that Earth orbited the Sun when it clearly seemed that Earth was at the center of the universe and everything moved around it, early adherents to the idea that continents could move had to fight a ...
... —the ground you sit on is moving! Just as Copernicus, Kepler, and Galileo had trouble convincing people that Earth orbited the Sun when it clearly seemed that Earth was at the center of the universe and everything moved around it, early adherents to the idea that continents could move had to fight a ...
Ocean Currents and Their Impact on Marine Life
... total because upwelling areas represent only 0.1% of the surface ocean. Because production in upwelling areas is enhanced mainly by the transport of allocthonous, nutrients, production in these systems in mostly new production, as opposed to the open ocean, where production is driven mainly by local ...
... total because upwelling areas represent only 0.1% of the surface ocean. Because production in upwelling areas is enhanced mainly by the transport of allocthonous, nutrients, production in these systems in mostly new production, as opposed to the open ocean, where production is driven mainly by local ...
Lecture 23: Hydrothermal Activity, Metamorphism
... proceeds at the surface. This also involves isotopic exchange. However, for the temperatures (~2° C) and minerals produced by these reactions (smectites, zeolites, etc.), fractionations are quite large (something like 20‰). The result of these reactions is to increase the δ18O of the shallow oceanic ...
... proceeds at the surface. This also involves isotopic exchange. However, for the temperatures (~2° C) and minerals produced by these reactions (smectites, zeolites, etc.), fractionations are quite large (something like 20‰). The result of these reactions is to increase the δ18O of the shallow oceanic ...
View - GFZpublic
... lected: a = upper crustal Paleozoic sedimentary rocks, b = upper crustal late Proterozoic to early Cambrian magmatic and metamorphic rocks, c = lower crustal granulites and upper mantle peridotites. Also shown are the locations of the boreholes used for heat‐flow calculation. The broken line repr ...
... lected: a = upper crustal Paleozoic sedimentary rocks, b = upper crustal late Proterozoic to early Cambrian magmatic and metamorphic rocks, c = lower crustal granulites and upper mantle peridotites. Also shown are the locations of the boreholes used for heat‐flow calculation. The broken line repr ...
Density structure and geometry of the Costa Rican subduction zone
... Tenorio and Rincon de la Vieja volcanoes and several temporary projects (Fig. 2). The network configuration has varied accordingly over time. At present, the subnetworks consist of four to eight, three-component, short-period stations each, and one broadband station at the Tenorio Volcano. Other tem ...
... Tenorio and Rincon de la Vieja volcanoes and several temporary projects (Fig. 2). The network configuration has varied accordingly over time. At present, the subnetworks consist of four to eight, three-component, short-period stations each, and one broadband station at the Tenorio Volcano. Other tem ...
A tensile, flexural model for the initiation of subduction
... initiate subduction. The sediments induce flexure at the margin and contribute, along with ridge push and isostasy, to the overall state of stress. Lithospheric failure was taken to occur when the stresses exceed the strength of the materials at all depths. T h e authors concluded that because the s ...
... initiate subduction. The sediments induce flexure at the margin and contribute, along with ridge push and isostasy, to the overall state of stress. Lithospheric failure was taken to occur when the stresses exceed the strength of the materials at all depths. T h e authors concluded that because the s ...
The structure of the upper mantle beneath the Delamerian and
... obvious concern with this distribution is that it has a very strong azimuthal variation, with many events located in the north and east and relatively few located in the south and west. This unevenness will produce undesirable artefacts in the tomographic results by way of smearing out of anomalies ...
... obvious concern with this distribution is that it has a very strong azimuthal variation, with many events located in the north and east and relatively few located in the south and west. This unevenness will produce undesirable artefacts in the tomographic results by way of smearing out of anomalies ...
Print this article - Latin American Journal of Aquatic Mammals
... southward direction (Peterson and Stramma, 1990; Stramma et al., 1990). The Malvinas Current is a branch of the Circumpolar Current and flows northward along the continental shelf of Argentina until it reaches the Brazil Current offshore La Plata River (Legeckis and Gordon, 1982; Garzoli, 1993; Vivi ...
... southward direction (Peterson and Stramma, 1990; Stramma et al., 1990). The Malvinas Current is a branch of the Circumpolar Current and flows northward along the continental shelf of Argentina until it reaches the Brazil Current offshore La Plata River (Legeckis and Gordon, 1982; Garzoli, 1993; Vivi ...
Petrological models of magma evolution and deep crustal structure
... a code for fractionation/assimilation processes in silicate liquids. MELTS is based on a rigorous thermodynamic formulation of liquid- and solid-phase equilibria. and it calculates the composition and amount of liquid and solid phases as a function of pressure, temperature and initial liquid composi ...
... a code for fractionation/assimilation processes in silicate liquids. MELTS is based on a rigorous thermodynamic formulation of liquid- and solid-phase equilibria. and it calculates the composition and amount of liquid and solid phases as a function of pressure, temperature and initial liquid composi ...
A tensile, flexural model for the initiation of subduction
... initiate subduction. The sediments induce flexure at the margin and contribute, along with ridge push and isostasy, to the overall state of stress. Lithospheric failure was taken to occur when the stresses exceed the strength of the materials at all depths. T h e authors concluded that because the s ...
... initiate subduction. The sediments induce flexure at the margin and contribute, along with ridge push and isostasy, to the overall state of stress. Lithospheric failure was taken to occur when the stresses exceed the strength of the materials at all depths. T h e authors concluded that because the s ...
Chemical and tracer studies in coral reef interstitial waters (French
... it may originate from the recycling of sponges and diatoms within the reef. However, in boreholes from Mururoa atoll, concentrations in silicate, low in the top layer of the reef, were reported to increase strongly at a depth of 450 m close to the volcanic basement (Rougerie, 1983; Rougerie and Waut ...
... it may originate from the recycling of sponges and diatoms within the reef. However, in boreholes from Mururoa atoll, concentrations in silicate, low in the top layer of the reef, were reported to increase strongly at a depth of 450 m close to the volcanic basement (Rougerie, 1983; Rougerie and Waut ...
Scott Tarlow (), Department of Earth and
... corner. Then, nodes on the surface are locked with zero plate velocity until 220 meters away from the trench, where the full spreading rate is then applied to the rest of the surface nodes. Slab dip is imposed by weak nodes (white lines), which allow the underlying slab to decouple from the overridi ...
... corner. Then, nodes on the surface are locked with zero plate velocity until 220 meters away from the trench, where the full spreading rate is then applied to the rest of the surface nodes. Slab dip is imposed by weak nodes (white lines), which allow the underlying slab to decouple from the overridi ...
Introduction to the special issue on “Subduction Zones”
... When an oceanic basin closes and continental lithosphere enters a subduction zone, the positive buoyancy of the continental crust will resist subduction, leading to a slow-down, and ultimately to the end of subduction (e.g., McKenzie, 1969). Continental collision is accompanied by severe crustal and ...
... When an oceanic basin closes and continental lithosphere enters a subduction zone, the positive buoyancy of the continental crust will resist subduction, leading to a slow-down, and ultimately to the end of subduction (e.g., McKenzie, 1969). Continental collision is accompanied by severe crustal and ...
plate boundaries
... QuickTime™ and a QuickTime™ and a TIFF (Uncompressed) decompressor TIFF (Uncompressed) decompressor are needed to see this picture. are needed to see this picture. ...
... QuickTime™ and a QuickTime™ and a TIFF (Uncompressed) decompressor TIFF (Uncompressed) decompressor are needed to see this picture. are needed to see this picture. ...
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.