Geology: Fluids in the lower crust following Mendocino triple
... lithologies, while the deeper reflections are at the level of Moho formation. This is similar to the midocean ridges where melt due to upwelling asthenosphere is found in discrete bodies, both shallow and near the oceanic Moho (Kent et al., 1993; Garmany, 1989). Because a 100 m thick sill solidifies ...
... lithologies, while the deeper reflections are at the level of Moho formation. This is similar to the midocean ridges where melt due to upwelling asthenosphere is found in discrete bodies, both shallow and near the oceanic Moho (Kent et al., 1993; Garmany, 1989). Because a 100 m thick sill solidifies ...
An off-axis hydrothermal vent field near the Mid
... Evidence is growing that hydrothermal venting occurs not only along mid-ocean ridges but also on old regions of the oceanic crust away from spreading centres. Here we report the discovery of an extensive hydrothermal ®eld at 308 N near the eastern intersection of the Mid-Atlantic Ridge and the Atlan ...
... Evidence is growing that hydrothermal venting occurs not only along mid-ocean ridges but also on old regions of the oceanic crust away from spreading centres. Here we report the discovery of an extensive hydrothermal ®eld at 308 N near the eastern intersection of the Mid-Atlantic Ridge and the Atlan ...
Slab Ocean El Niño atmospheric feedbacks in Coupled Climate
... Dommenget (2010) found that El Niño-like variability, termed Slab Ocean El Niño, can exist in the absence of ocean dynamics and is driven by the interaction of the atmospheric surface heat fluxes and the heat content of the upper ocean. Further, Dommenget et al. (2014) report the Slab Ocean El Niño ...
... Dommenget (2010) found that El Niño-like variability, termed Slab Ocean El Niño, can exist in the absence of ocean dynamics and is driven by the interaction of the atmospheric surface heat fluxes and the heat content of the upper ocean. Further, Dommenget et al. (2014) report the Slab Ocean El Niño ...
pdf-file - Art Periods
... and 40°S, where the largest coseismic displacement of the 1960 Valdivia earthquake occurred. A lowvelocity anomaly and high Vp/Vs values occur under the coastal region, indicating mantle serpentinisation and/or underthrusting of forearc material. Further east, a high-velocity anomaly is observed, in ...
... and 40°S, where the largest coseismic displacement of the 1960 Valdivia earthquake occurred. A lowvelocity anomaly and high Vp/Vs values occur under the coastal region, indicating mantle serpentinisation and/or underthrusting of forearc material. Further east, a high-velocity anomaly is observed, in ...
Sustainability of deep-sea fish species under the European Union
... fleet by 34e44% between 1990 and 2006. Since then, according to data from Eurostat,4 the fishing capacity of the deep-sea fleet has increased by about 3% until 2010. The bathymetric expansion of the EU fleets can be seen in all oceans (except for the Central Pacific FAO areas), but it is particularly imp ...
... fleet by 34e44% between 1990 and 2006. Since then, according to data from Eurostat,4 the fishing capacity of the deep-sea fleet has increased by about 3% until 2010. The bathymetric expansion of the EU fleets can be seen in all oceans (except for the Central Pacific FAO areas), but it is particularly imp ...
Is plate tectonics really occurring today?
... to move plates sufficient? These forces have to act on the bottom and/or sides of the plates. The forces on the bottom of plates are the horizontal forces below the lithosphere caused by putative convection currents, while the forces on the sides are called ‘ridge push’ near mid-ocean ridges (MORs) ...
... to move plates sufficient? These forces have to act on the bottom and/or sides of the plates. The forces on the bottom of plates are the horizontal forces below the lithosphere caused by putative convection currents, while the forces on the sides are called ‘ridge push’ near mid-ocean ridges (MORs) ...
Lecture 2
... Sea (surrounded by industrilized land) (Sen Gupta, 1973). In Narragansett Bay, precipitation contributes 0.5 % of the N entering the area (surrounding area is less urbanized). Precipitation is important for the open waters, stratified water bodies such as subtropical gyres where there are few other ...
... Sea (surrounded by industrilized land) (Sen Gupta, 1973). In Narragansett Bay, precipitation contributes 0.5 % of the N entering the area (surrounding area is less urbanized). Precipitation is important for the open waters, stratified water bodies such as subtropical gyres where there are few other ...
Slide 1
... Analog models Numerical Models Modeling Foreland Basin Moving tectonic load Erosion and deposition of bivergent margins ...
... Analog models Numerical Models Modeling Foreland Basin Moving tectonic load Erosion and deposition of bivergent margins ...
Developing a Vision for Climate Variability Research in the
... meridional heat flux in response to wind changes, as eddies and Ekman fluxes both modulate heat transfer with different depth profiles. Correct resolution of the poleward eddy heat transport is thus an important consideration in getting the correct temperature and sea ice response to anthropogenic c ...
... meridional heat flux in response to wind changes, as eddies and Ekman fluxes both modulate heat transfer with different depth profiles. Correct resolution of the poleward eddy heat transport is thus an important consideration in getting the correct temperature and sea ice response to anthropogenic c ...
Plate Tectonics: GL209 Prof. John Tarney Lecture 5: Subduction
... either still active (1), or recently active (2). The third may represent basins formed by even older back-arc spreading, or normal ocean crust that has been "trapped" behind a recently developed oceanic island arc. ...
... either still active (1), or recently active (2). The third may represent basins formed by even older back-arc spreading, or normal ocean crust that has been "trapped" behind a recently developed oceanic island arc. ...
- SEAFDEC
... without association with the sea floor, might be considered deep water fisheries ( as the species occur at depths of at least 200 m). However, these species generally do not grow to a large enough size to make them valuable commercial fisheries and/or they have not proven to be viable commercial fis ...
... without association with the sea floor, might be considered deep water fisheries ( as the species occur at depths of at least 200 m). However, these species generally do not grow to a large enough size to make them valuable commercial fisheries and/or they have not proven to be viable commercial fis ...
APPLICATION FOR CONSENT TO CONDUCT MARINE SCIENTIFIC
... 1900 m. The moored instrument within its protection metal-frame is about 1m high above the bottom, while the mooring heads are below -160 m (see Figure 3 for details). This projet is a contribution to the international CLIVAR program and complements work planned by other European groups in the subpo ...
... 1900 m. The moored instrument within its protection metal-frame is about 1m high above the bottom, while the mooring heads are below -160 m (see Figure 3 for details). This projet is a contribution to the international CLIVAR program and complements work planned by other European groups in the subpo ...
The Global Phosphorus Cycle: Past, Present
... the filter of the geologic record. For example, the most recent paradigm for the episodic nature of large marine deposits rich in P, called phosphorites and typified by the massive Permian Phosphoria Formation of the western US, was that these deposits reflect times in Earth’s history when the trans ...
... the filter of the geologic record. For example, the most recent paradigm for the episodic nature of large marine deposits rich in P, called phosphorites and typified by the massive Permian Phosphoria Formation of the western US, was that these deposits reflect times in Earth’s history when the trans ...
Plate Tectonics Review with Answers Rich Text
... 11. Plates slide past one another at ____. a. subduction zones b. transform boundaries ...
... 11. Plates slide past one another at ____. a. subduction zones b. transform boundaries ...
Part 3
... This gives rise to continental crust reaching a thickness of about 70 km where as the average thickness of continental crust is about 40 km. The mechanism for why this type of subduction occurs is still being debated. One theory suggests the attachment of the oceanic plates either side of the Indian ...
... This gives rise to continental crust reaching a thickness of about 70 km where as the average thickness of continental crust is about 40 km. The mechanism for why this type of subduction occurs is still being debated. One theory suggests the attachment of the oceanic plates either side of the Indian ...
mid-ocean ridge tectonics, volcanism and
... ations in mechanical thinning of the crust by faulting. There is no conSict between these models, so both focused upwelling and mechanical thinning may occur along each segment. One might expect the same to hold at fast-spreading centers, i.e., crustal thinning adjacent to OSCs. This does not appear ...
... ations in mechanical thinning of the crust by faulting. There is no conSict between these models, so both focused upwelling and mechanical thinning may occur along each segment. One might expect the same to hold at fast-spreading centers, i.e., crustal thinning adjacent to OSCs. This does not appear ...
Alfred Wegener and Harry Hess
... plates float on top of the mantle. Pockets of hot liquid magma in the mantle ooze up along mountain ridges deep under the water. One runs north-south in the middle of the Atlantic Ocean. Another runs in the mid-Pacific Ocean. Along these ridges are active volcanoes and hot-water vents. Very hot, min ...
... plates float on top of the mantle. Pockets of hot liquid magma in the mantle ooze up along mountain ridges deep under the water. One runs north-south in the middle of the Atlantic Ocean. Another runs in the mid-Pacific Ocean. Along these ridges are active volcanoes and hot-water vents. Very hot, min ...
Ocean ridges - dynamicearth.de
... transition to a mineralogy of lower density. Suppose the average temperature to a depth of 100 km below the Moho is 500°C greater at the ridge crest than beneath the flanking regions, the average density to this depth is 3.3 Mg m−3 and the volume coefficient of thermal expansion is 3 × 10−5 per degr ...
... transition to a mineralogy of lower density. Suppose the average temperature to a depth of 100 km below the Moho is 500°C greater at the ridge crest than beneath the flanking regions, the average density to this depth is 3.3 Mg m−3 and the volume coefficient of thermal expansion is 3 × 10−5 per degr ...
U.S. JGOFS NEWS
... margins, and there is little northsouth gradient in the critical region between 30°N and 50°N. We hypothesize that this pattern could be produced if production in the high latitudes of the North Atlantic is lightly ballasted, so that not much of it sinks to the sea floor, and if coastal processes, b ...
... margins, and there is little northsouth gradient in the critical region between 30°N and 50°N. We hypothesize that this pattern could be produced if production in the high latitudes of the North Atlantic is lightly ballasted, so that not much of it sinks to the sea floor, and if coastal processes, b ...
Equatorial ocean circulation in an extremely warm climate
... crustal transect (Figure 1). These high amplitude reflections are thought to represent carbonate-rich sediments deposited near the ridge crest, an interpretation supported by results from regional DSDP sites. As the crust subsided away from the crestal area, the seafloor soon sank beneath the very s ...
... crustal transect (Figure 1). These high amplitude reflections are thought to represent carbonate-rich sediments deposited near the ridge crest, an interpretation supported by results from regional DSDP sites. As the crust subsided away from the crestal area, the seafloor soon sank beneath the very s ...
Oregon State University | College of Oceanic and Atmospheric
... respects to other subduction zones, the rate of both upper and lower plate seismicity is much lower than is generally found in such tectonic settings (2). Damaging earthquakes in northern California in 1992 and in Oregon in 1993, however, reveal the potential for significant seismic activity in this ...
... respects to other subduction zones, the rate of both upper and lower plate seismicity is much lower than is generally found in such tectonic settings (2). Damaging earthquakes in northern California in 1992 and in Oregon in 1993, however, reveal the potential for significant seismic activity in this ...
Durham Research Online
... at Iceland, nonetheless. What alternative hypothesis can be offered? The Iceland region persistently produces up to three times the amount of melt produced on the north Atlantic spreading ridge without greatly elevated temperatures, and rock compositions are similar to those observed at “normal” sub ...
... at Iceland, nonetheless. What alternative hypothesis can be offered? The Iceland region persistently produces up to three times the amount of melt produced on the north Atlantic spreading ridge without greatly elevated temperatures, and rock compositions are similar to those observed at “normal” sub ...
Technologies for Exploring the Exclusive Economic Zone
... thereby increasing exploration efficiency. Data sets ...
... thereby increasing exploration efficiency. Data sets ...
Plumes, or plate tectonic processes?
... at Iceland, nonetheless. What alternative hypothesis can be offered? The Iceland region persistently produces up to three times the amount of melt produced on the north Atlantic spreading ridge without greatly elevated temperatures, and rock compositions are similar to those observed at “normal” sub ...
... at Iceland, nonetheless. What alternative hypothesis can be offered? The Iceland region persistently produces up to three times the amount of melt produced on the north Atlantic spreading ridge without greatly elevated temperatures, and rock compositions are similar to those observed at “normal” sub ...
The Origin of the Land Under the Sea
... the melt is concentrated into less than 10 percent of the available area. That means millions of microscopic threads of flowing melt may eventually feed into only a few dozen, highporosity channels 100 meters or more wide. Even in the widest channels, many crystals of the original mantle rock remain ...
... the melt is concentrated into less than 10 percent of the available area. That means millions of microscopic threads of flowing melt may eventually feed into only a few dozen, highporosity channels 100 meters or more wide. Even in the widest channels, many crystals of the original mantle rock remain ...
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.