Accelerated Non-linear Destruction of the Earth`s Crust
... the Earth’s mantle which are denser than the crust. The crust and uppermost mantle form a rigid lithospheric layer. Over most of the continental areas, where the heat flow from the Earth’s interior is low, the lithospheric thickness is 100-200 km. Due to a temperature increase with depth, a strong d ...
... the Earth’s mantle which are denser than the crust. The crust and uppermost mantle form a rigid lithospheric layer. Over most of the continental areas, where the heat flow from the Earth’s interior is low, the lithospheric thickness is 100-200 km. Due to a temperature increase with depth, a strong d ...
A review of deep-sea benthic biodiversity associated with trench
... We review the state of knowledge of benthic biodiversity and ecosystem functioning in deep-sea abyssal, canyon and trench habitats in the New Zealand Exclusive Economic Zone and the Ross Dependency, and make recommendations for future deep-sea research in depths exceeding 1500 m. All biological info ...
... We review the state of knowledge of benthic biodiversity and ecosystem functioning in deep-sea abyssal, canyon and trench habitats in the New Zealand Exclusive Economic Zone and the Ross Dependency, and make recommendations for future deep-sea research in depths exceeding 1500 m. All biological info ...
Neodymium isotopic variations in North Pacific modern
... to - 4 and slightly lower ENd in bottom waters along the western North Pacific due to the incursion of Antarctic Bottom Water. The relative homogeneity of bottom water ENd, which contrasts sharply with the distinctive variation in sediment ENd, plus the large difference between the average end of bo ...
... to - 4 and slightly lower ENd in bottom waters along the western North Pacific due to the incursion of Antarctic Bottom Water. The relative homogeneity of bottom water ENd, which contrasts sharply with the distinctive variation in sediment ENd, plus the large difference between the average end of bo ...
Gernigon, L., O. Olesen, J. Ebbing, S. Wienecke
... Spur (VS), an anomalous oceanic high, lying north of the eastern segment of the JMFZ exhibits a contrasting Bouguer gravity low and a complex magnetic signature. The gravity signature of the VS can be modelled and explained as an abnormal thick oceanic crust, which locally can reach up to 15 km. We ...
... Spur (VS), an anomalous oceanic high, lying north of the eastern segment of the JMFZ exhibits a contrasting Bouguer gravity low and a complex magnetic signature. The gravity signature of the VS can be modelled and explained as an abnormal thick oceanic crust, which locally can reach up to 15 km. We ...
Status and trends of, and threats to, deep seabed genetic
... material of actual or potential value. Genetic material is defined as any material of plant, animal, microbial or other origin containing functional units of heredity. It follows that marine genetic resources are marine plants, animals and microorganisms, and parts thereof containing functional unit ...
... material of actual or potential value. Genetic material is defined as any material of plant, animal, microbial or other origin containing functional units of heredity. It follows that marine genetic resources are marine plants, animals and microorganisms, and parts thereof containing functional unit ...
Site 398 : Evolution of the west iberian passive continental margin in
... J Anomaly and the Beginning of True Sea-Floor Spreading in the Northern Atlantic Following the above events, the history of the Tethyan Ocean becomes independent of the Atlantic evolution. While compressive phases induced the first Alpine deformations, opening of the Atlantic is occurring. A first a ...
... J Anomaly and the Beginning of True Sea-Floor Spreading in the Northern Atlantic Following the above events, the history of the Tethyan Ocean becomes independent of the Atlantic evolution. While compressive phases induced the first Alpine deformations, opening of the Atlantic is occurring. A first a ...
This is the A) Pacific plate B) North American plate C) Quinn Plate D
... • Why are earthquakes always less than 35 km deep at mid‐ocean ridges? A) they are far from seismometers on land so the depth of the earthquake is not determined very accurately B) The crust is sAll hot and has not had Ame to cool so it is very thin, and earthquakes can only occur in the t ...
... • Why are earthquakes always less than 35 km deep at mid‐ocean ridges? A) they are far from seismometers on land so the depth of the earthquake is not determined very accurately B) The crust is sAll hot and has not had Ame to cool so it is very thin, and earthquakes can only occur in the t ...
spatial gaps in arc volcanism: the effect of collision or subduction of
... crust (Gill, 1981). The moving slab although itself cold, provides the heat for melting by causing convection within the wedge and also possibly by frictional heating along the slab--wedge interface. The slab also contains water and other volatiles which, if they escape into the overlying mantle, ma ...
... crust (Gill, 1981). The moving slab although itself cold, provides the heat for melting by causing convection within the wedge and also possibly by frictional heating along the slab--wedge interface. The slab also contains water and other volatiles which, if they escape into the overlying mantle, ma ...
Stories in IPRC Climate
... soon pushed to higher latitudes by the divergence associated with the equatorial upwelling forming the famous “cold tongue” along the equator. Other massive drifter launches occurred off the California and the US East Coast, as well as in the Japan Sea. These drifters have not been dispersed much by ...
... soon pushed to higher latitudes by the divergence associated with the equatorial upwelling forming the famous “cold tongue” along the equator. Other massive drifter launches occurred off the California and the US East Coast, as well as in the Japan Sea. These drifters have not been dispersed much by ...
2.1.1 Introduction
... travel path increases. By making use of a standard model for the velocity stratification of the Earth, and employing many seismic phases corresponding to different travel paths along which the seismic waves are refracted or reflected at velocity discontinuities, it is possible to translate the diffe ...
... travel path increases. By making use of a standard model for the velocity stratification of the Earth, and employing many seismic phases corresponding to different travel paths along which the seismic waves are refracted or reflected at velocity discontinuities, it is possible to translate the diffe ...
Radionuclides in deep-sea fish and other
... contributions to the diet. For example, the annual seafood consumption in the UK averages 10 kg year21 per capita, whereas in Portugal it averages 60 kg year21 per capita and in Japan it accounts for 64 kg year21 per capita. 210Po ingested with the diet gives rise to average daily intakes of 210Po e ...
... contributions to the diet. For example, the annual seafood consumption in the UK averages 10 kg year21 per capita, whereas in Portugal it averages 60 kg year21 per capita and in Japan it accounts for 64 kg year21 per capita. 210Po ingested with the diet gives rise to average daily intakes of 210Po e ...
Melting features along the Ryukyu slab tear, beneath the
... magnetic source, assumed to be the Curie point depth, is then calculated by Zb = 2Z0 Zt. [6] In order to enhance the broad features linked to deep features, the centroid depths were calculated for wavelengths larger than 10 km [Stampolidis and Tsokas, 2002; Tanaka et al., 1999]. Zt, Zb and the thi ...
... magnetic source, assumed to be the Curie point depth, is then calculated by Zb = 2Z0 Zt. [6] In order to enhance the broad features linked to deep features, the centroid depths were calculated for wavelengths larger than 10 km [Stampolidis and Tsokas, 2002; Tanaka et al., 1999]. Zt, Zb and the thi ...
Deep Sea Drilling Project Initial Reports Volume 87
... the submarine topography was gentle and that the lower deep-sea terrace was relatively steeper than the trench slope in the late Miocene and Pliocene. Sediments underlying the Pliocene-upper Miocene were drilled at Sites 438, 439, and 584 and dated as late Oligocene to late Miocene (25-10 Ma). Their ...
... the submarine topography was gentle and that the lower deep-sea terrace was relatively steeper than the trench slope in the late Miocene and Pliocene. Sediments underlying the Pliocene-upper Miocene were drilled at Sites 438, 439, and 584 and dated as late Oligocene to late Miocene (25-10 Ma). Their ...
Faulting and hydration of the Juan de Fuca plate system
... largely restricted to crustal levels. If dehydration embrittlement is an important mechanism for triggering intermediate-depth earthquakes within the subducting slab, then the limited occurrence rate and magnitude of intraslab seismicity at the Cascadia margin may in part be explained by the limited ...
... largely restricted to crustal levels. If dehydration embrittlement is an important mechanism for triggering intermediate-depth earthquakes within the subducting slab, then the limited occurrence rate and magnitude of intraslab seismicity at the Cascadia margin may in part be explained by the limited ...
- Stanford University
... marine multichannel reflection data. The airgun shots were moved to basement using a shift in horizontal position, vertical position, and time. This shift used straight rays in the water column and in the sediment. Each ray pointed toward the receiver with a takeoff angle calculated from an apparent ...
... marine multichannel reflection data. The airgun shots were moved to basement using a shift in horizontal position, vertical position, and time. This shift used straight rays in the water column and in the sediment. Each ray pointed toward the receiver with a takeoff angle calculated from an apparent ...
Lozier 2010 - Sites@Duke
... study finds that most of the subpolar-to- has actually been under way for a number of subtropics and equatorward (15, 16). Although subtropical exchange in the North Atlantic years. As pointed out in 2002 (14), the conveyor the geochemical tracers in this DWBC conoccurs along interior pathways (9), ...
... study finds that most of the subpolar-to- has actually been under way for a number of subtropics and equatorward (15, 16). Although subtropical exchange in the North Atlantic years. As pointed out in 2002 (14), the conveyor the geochemical tracers in this DWBC conoccurs along interior pathways (9), ...
fractured basement a case study
... Tight/fresh blocks are dominant and can be observed both in outcrops as well as in the wells sections Tight/fresh blocks increase with depth of buried basement ...
... Tight/fresh blocks are dominant and can be observed both in outcrops as well as in the wells sections Tight/fresh blocks increase with depth of buried basement ...
Structure and rheology of lithosphere in Italy and surrounding.
... average Vs and its range of variability in km s)1 are printed on each layer and a hatched rectangular zone outlines the range of variability of their thicknesses. For the sake of clarity, in the uppermost crustal layers the values of Vs are omitted; these values are given in Farina (2006) and Panza ...
... average Vs and its range of variability in km s)1 are printed on each layer and a hatched rectangular zone outlines the range of variability of their thicknesses. For the sake of clarity, in the uppermost crustal layers the values of Vs are omitted; these values are given in Farina (2006) and Panza ...
P corner, Japan-Kurile arc-arc junction Kei Katsumata, Naoto Wada, and Minoru Kasahara
... hypocentral distribution, we did not assume this model in our tomography. We will compare Katsumata’s model with the seismic activity is very high down to the upper mantle velocity structures in this study. due to the collision between the Kurile Islands arc and the northeastern Japan arc. A seismic ...
... hypocentral distribution, we did not assume this model in our tomography. We will compare Katsumata’s model with the seismic activity is very high down to the upper mantle velocity structures in this study. due to the collision between the Kurile Islands arc and the northeastern Japan arc. A seismic ...
Mantle Convection and Global Sea Level: Implications for the
... that T m was higher by ca. 200°C at 3 Ga than present based on the FeO and SiO2 contents of the initial magmas estimated from MORB-type volcanic rocks found in the Archean-early Proterozoic accretionary prisms. We assume that T m was higher by 200°C at 3 Ga than Tm* ( = 1280°C, McKenzie and Bickle, ...
... that T m was higher by ca. 200°C at 3 Ga than present based on the FeO and SiO2 contents of the initial magmas estimated from MORB-type volcanic rocks found in the Archean-early Proterozoic accretionary prisms. We assume that T m was higher by 200°C at 3 Ga than Tm* ( = 1280°C, McKenzie and Bickle, ...
The lithosphere under stress
... can well up to be the base of the oceanic crust at the spreading axis also causes a decrease in the amount of melt generated from mantle at a given temperature. The first change works in the opposite direction to the second two changes, and the revised estimate of mantle temperature is little altere ...
... can well up to be the base of the oceanic crust at the spreading axis also causes a decrease in the amount of melt generated from mantle at a given temperature. The first change works in the opposite direction to the second two changes, and the revised estimate of mantle temperature is little altere ...
Subduction-driven recycling of continental margin lithosphere
... tectonic settings. We have developed teleseismic body wave images from dense broadband seismic experiments that show higher than expected volumes of anomalously fast mantle associated with the subducted Atlantic slab under northeastern South America and the Alboran slab beneath the Gibraltar arc reg ...
... tectonic settings. We have developed teleseismic body wave images from dense broadband seismic experiments that show higher than expected volumes of anomalously fast mantle associated with the subducted Atlantic slab under northeastern South America and the Alboran slab beneath the Gibraltar arc reg ...
Chapter 4: Marine sediments
... Metal sulfides Contain iron, nickel, copper, zinc, silver, and other metals Associated with hydrothermal vents ...
... Metal sulfides Contain iron, nickel, copper, zinc, silver, and other metals Associated with hydrothermal vents ...
Polarity Reversal of Active Plate Boundary and Elevated Oceanic
... VP /VS mid-to-lower continental crust to the west. A significant amount of plate convergence along the suture has been accommodated by the high-angle thrusting along the northern LVF. In contrast, a southeast-dipping seismic zone can be identified extending from the surface to ⬃25 km depth near Tait ...
... VP /VS mid-to-lower continental crust to the west. A significant amount of plate convergence along the suture has been accommodated by the high-angle thrusting along the northern LVF. In contrast, a southeast-dipping seismic zone can be identified extending from the surface to ⬃25 km depth near Tait ...
Pacific microplate and the Pangea supercontinent in the Early to
... pulse in mantle plume activity forming oceanic plateaus on the Pacific plate at that time. This lack of evidence for mantle plume activity beneath the Pacific is not absolute proof there was none, as it all might have occurred on surrounding plates, which are now mostly subducted. However, that seem ...
... pulse in mantle plume activity forming oceanic plateaus on the Pacific plate at that time. This lack of evidence for mantle plume activity beneath the Pacific is not absolute proof there was none, as it all might have occurred on surrounding plates, which are now mostly subducted. However, that seem ...
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.