International Journal of Advanced Scientific and Technical Research
... Two contact zones were found in the study area. The first one exists between Ophiolite and Mithakhari sediment group. The second one exists in between Mithakhari and Andaman Flysch sediment group. Both of these contact zones were found to be vertical and smooth. The present study has clearly shown t ...
... Two contact zones were found in the study area. The first one exists between Ophiolite and Mithakhari sediment group. The second one exists in between Mithakhari and Andaman Flysch sediment group. Both of these contact zones were found to be vertical and smooth. The present study has clearly shown t ...
PDF 51 - The Open University
... book The Age of the Earth. Importantly, his second famous book Principles of Physical Geology did not follow the traditional viewpoints and concluded with a chapter describing continental drift. 1940-1960 The complexity of ocean floor topography was realised through improvements to sonar equipment d ...
... book The Age of the Earth. Importantly, his second famous book Principles of Physical Geology did not follow the traditional viewpoints and concluded with a chapter describing continental drift. 1940-1960 The complexity of ocean floor topography was realised through improvements to sonar equipment d ...
Linking rift propagation barriers to excess magmatism at volcanic
... (Fig. 1). Segmentation is recorded in the southern South Atlantic in seaward-dipping reflector (SDR) distribution and magnetic anomalies (e.g., Clemson et al., 1997; Franke et al., 2007; Koopmann et al., 2014a). For the North Atlantic between Norway and Greenland, segmentation has also been observed ...
... (Fig. 1). Segmentation is recorded in the southern South Atlantic in seaward-dipping reflector (SDR) distribution and magnetic anomalies (e.g., Clemson et al., 1997; Franke et al., 2007; Koopmann et al., 2014a). For the North Atlantic between Norway and Greenland, segmentation has also been observed ...
extension systems - The Web site cannot be found
... as fissure eruptions along and on either side of the splitting linear region (graben and rifts). This mechanism, coeval lithospheric stretching and accretion of buoyant magma, is called rifting. It is called seafloor spreading once a rifted region becomes a plate boundary that creates new oceanic li ...
... as fissure eruptions along and on either side of the splitting linear region (graben and rifts). This mechanism, coeval lithospheric stretching and accretion of buoyant magma, is called rifting. It is called seafloor spreading once a rifted region becomes a plate boundary that creates new oceanic li ...
Reflected-diffracted waves in fracture zone models
... The kinematic properties of travel times of waves reflected and diffracted in a fracture zone depend o n the size o f the fault throw A h , the fault width A x and the position of the wave source in relation t o the whole fracture zone, The minimum points and the osculation points to the reflected w ...
... The kinematic properties of travel times of waves reflected and diffracted in a fracture zone depend o n the size o f the fault throw A h , the fault width A x and the position of the wave source in relation t o the whole fracture zone, The minimum points and the osculation points to the reflected w ...
HeidiBerkenbosch - University of Washington
... The Galápagos Islands are a group of volcanoes that were formed by a mantle hotspot underneath a tectonic plate; a similar mechanism formed the Hawaiian Islands. The hot magma rising from the mantle plume underneath the plate is lighter in density than the overlying crust. The magma pushes up agains ...
... The Galápagos Islands are a group of volcanoes that were formed by a mantle hotspot underneath a tectonic plate; a similar mechanism formed the Hawaiian Islands. The hot magma rising from the mantle plume underneath the plate is lighter in density than the overlying crust. The magma pushes up agains ...
Salinity Patterns in the Ocean
... In this process, waters in the surface mixed layer circulate equatorward, encountering warmer, less dense waters to the south, which they are carried beneath. Surface waters are most saline in the middle of these subtropical regions. Therefore, all equatorward subtropical regions are characterized b ...
... In this process, waters in the surface mixed layer circulate equatorward, encountering warmer, less dense waters to the south, which they are carried beneath. Surface waters are most saline in the middle of these subtropical regions. Therefore, all equatorward subtropical regions are characterized b ...
Lytic viral infection of bacterioplankton in deep
... the western Pacific Ocean. Both the prokaryotic and viral abundance and production showed a significantly decreasing trend from epipelagic to meso- and bathypelagic waters. Viral abundance decreased from 0.36–1.05 × 1010 particles L−1 to 0.43–0.80 × 109 particles L−1 , while the virus : prokaryote r ...
... the western Pacific Ocean. Both the prokaryotic and viral abundance and production showed a significantly decreasing trend from epipelagic to meso- and bathypelagic waters. Viral abundance decreased from 0.36–1.05 × 1010 particles L−1 to 0.43–0.80 × 109 particles L−1 , while the virus : prokaryote r ...
Ocean Acidification and the End-Permian Mass Extinction: To What
... these beds shows physical evidence that can be unequivocally attributed to submarine dissolution. Pressure solution forming stylolites at bed contacts is a significant problem for analysis of facies change in this locality [12]. In the Dolomites of Italy, at another western Tethyan site, grain disso ...
... these beds shows physical evidence that can be unequivocally attributed to submarine dissolution. Pressure solution forming stylolites at bed contacts is a significant problem for analysis of facies change in this locality [12]. In the Dolomites of Italy, at another western Tethyan site, grain disso ...
Anaerobic bacteria in the sediment oxidaze methane present in the
... Cold seeps are deep-sea environments where methane gas or hydrogen sulfide is released from large storage of the seafloor by slow diffusion. Fluid flow is driven by pressure gradients created through tectonic compaction, unsteady sedimentation and diagenetic processes. Cold seeps are mainly located ...
... Cold seeps are deep-sea environments where methane gas or hydrogen sulfide is released from large storage of the seafloor by slow diffusion. Fluid flow is driven by pressure gradients created through tectonic compaction, unsteady sedimentation and diagenetic processes. Cold seeps are mainly located ...
Future of the Ocean and its Seas: a non
... nations – Canada, France, Germany, Italy, Japan, UK and USA – not only have direct responsibility for around 40 million km2 of marine habitat (nearly twice their total land area), but together they produce the overwhelming majority (more than 80%; Jappe, 2007) of oceanographic scientific publication ...
... nations – Canada, France, Germany, Italy, Japan, UK and USA – not only have direct responsibility for around 40 million km2 of marine habitat (nearly twice their total land area), but together they produce the overwhelming majority (more than 80%; Jappe, 2007) of oceanographic scientific publication ...
relationships between nodule genesis and topography in the
... Using the results of its comprehensive research and analysis of regional geological and geophysical data, IOM selected, within 1987-1990, a prospecting area of about 553 thou. km2 within which to conduct multi-faceted geological and geophysical studies. The studies carried out in the eastern part of ...
... Using the results of its comprehensive research and analysis of regional geological and geophysical data, IOM selected, within 1987-1990, a prospecting area of about 553 thou. km2 within which to conduct multi-faceted geological and geophysical studies. The studies carried out in the eastern part of ...
Pb composition of Mesozoic Pacific oceanic crust
... Concerning Site 1149 (Abrams, personal communication) the thickness of the cherts decreases while the thickness of the clays increases in northward. The total thickness of the subducted sediment, however, stays more or less constant. Strong links between the lithology and geochemistry exist for most ...
... Concerning Site 1149 (Abrams, personal communication) the thickness of the cherts decreases while the thickness of the clays increases in northward. The total thickness of the subducted sediment, however, stays more or less constant. Strong links between the lithology and geochemistry exist for most ...
Insight into collision zone dynamics from topography
... collision zone (Lei and Zhao, 2007), which shows low velocity regions where the slab would be expected. These low velocity regions can be interpreted as areas where the slab is no longer present and has been replaced by hot mantle material. Neo-Tethys opened in the Permian (Şengör et al., 1988) ma ...
... collision zone (Lei and Zhao, 2007), which shows low velocity regions where the slab would be expected. These low velocity regions can be interpreted as areas where the slab is no longer present and has been replaced by hot mantle material. Neo-Tethys opened in the Permian (Şengör et al., 1988) ma ...
View - GFZpublic
... 1. Introduction [2] Collisions between continents and volcanic island arcs are common elements in the ancient to recent tectonic history of the Earth. Many of these collisions are oblique and diachronous, starting where the two plates first collide then closing gradually like a zipper. This implies ...
... 1. Introduction [2] Collisions between continents and volcanic island arcs are common elements in the ancient to recent tectonic history of the Earth. Many of these collisions are oblique and diachronous, starting where the two plates first collide then closing gradually like a zipper. This implies ...
Origin of Archean subcontinental lithospheric mantle: Some
... results in progressive change in the composition of the residue, from fertile lherzolite at the first, high-pressure stage of melting, to highly refractory dunite at the final low-pressure stage. As a result of a process that is not well understood, the residues of melting then accumulate near the sur ...
... results in progressive change in the composition of the residue, from fertile lherzolite at the first, high-pressure stage of melting, to highly refractory dunite at the final low-pressure stage. As a result of a process that is not well understood, the residues of melting then accumulate near the sur ...
12. Interpretation of Multichannel Seismic Reflection Data, Legs 56
... The Japanese Deep Sea Expeditions in 1959 marked the beginning of systematic continuous echo sounding in the area off northern Honshu. The flat topographic area 2000 to 3000 meters deep just west of Japan Trench axis was first defined in the results reported by Nasu and others (1960) and Nasu and Sa ...
... The Japanese Deep Sea Expeditions in 1959 marked the beginning of systematic continuous echo sounding in the area off northern Honshu. The flat topographic area 2000 to 3000 meters deep just west of Japan Trench axis was first defined in the results reported by Nasu and others (1960) and Nasu and Sa ...
Impact origin for the greater Ontong Java Plateau?
... drilled or sampled from obducted Solomon Islands sections, erupted below sea level, and sediments deposited just above this basement are marine [11,13] (Fig. 2b). Plateaus within oceanic lithosphere should subside via either thermal conduction [30] or continuous viscous spreading of the anomalous ma ...
... drilled or sampled from obducted Solomon Islands sections, erupted below sea level, and sediments deposited just above this basement are marine [11,13] (Fig. 2b). Plateaus within oceanic lithosphere should subside via either thermal conduction [30] or continuous viscous spreading of the anomalous ma ...
Tectonic erosion along the Japan and Peru convergent margins
... much less attention. The difference in attention may result from the difficulty in resolving erosional structures in seismic records. Tectonic foreshortening of the lower slope of a trench has been reported and is explained by lateral translation of terranes or by erosion of the upper plate through ...
... much less attention. The difference in attention may result from the difficulty in resolving erosional structures in seismic records. Tectonic foreshortening of the lower slope of a trench has been reported and is explained by lateral translation of terranes or by erosion of the upper plate through ...
Ocean storage
... which illustrates that CO2 is consumed and O2 produced in the overall chain of reactions. CO2 may be either absorbed directly from the air, as is the case for terrestrial plants, or obtained from CO2 dissolved in the surface seawater. Phytoplankton also require nutrients such as nitrate, phosphate, ...
... which illustrates that CO2 is consumed and O2 produced in the overall chain of reactions. CO2 may be either absorbed directly from the air, as is the case for terrestrial plants, or obtained from CO2 dissolved in the surface seawater. Phytoplankton also require nutrients such as nitrate, phosphate, ...
Consultative Draft, V5 November, 2016
... system. Roughly equivalent volumes of dense water sink in the North Atlantic and Antarctic limbs of the MOC and are transported to distant ocean basins. Despite their importance, long-term repeated direct velocity observations of the DWBCs in the Atlantic exist only in a few locations in the North ...
... system. Roughly equivalent volumes of dense water sink in the North Atlantic and Antarctic limbs of the MOC and are transported to distant ocean basins. Despite their importance, long-term repeated direct velocity observations of the DWBCs in the Atlantic exist only in a few locations in the North ...
synthesis and review of the best available scientific studies on
... 17. A review of studies on the biogeography and biodiversity of seamounts found that rates of endemism between 10% and 50% had been reported in medium and large-scale studies while the level of seamount biodiversity relative to other habitats in similar environments varied between studies62. On the ...
... 17. A review of studies on the biogeography and biodiversity of seamounts found that rates of endemism between 10% and 50% had been reported in medium and large-scale studies while the level of seamount biodiversity relative to other habitats in similar environments varied between studies62. On the ...
Continent–ocean transition and voluminous magmatic underplating
... were derived from forward traveltime modelling of land stations and ocean bottom hydrophone (OBH) recordings. For the first time, long deep seismic sounding transects off East Greenland provide a full insight into the crustal architecture of the transition from continental to oceanic crust. A mean r ...
... were derived from forward traveltime modelling of land stations and ocean bottom hydrophone (OBH) recordings. For the first time, long deep seismic sounding transects off East Greenland provide a full insight into the crustal architecture of the transition from continental to oceanic crust. A mean r ...
101 Questions and Answers Concerning
... basaltic in composition, that this basalt had been generated at a mid-ocean ridge via partial melting of mantle rock below as part of the seafloor spreading process, and that all of crustal basement rocks of today’s ocean floor were no older than Mesozoic in age. Among the implications were that the ...
... basaltic in composition, that this basalt had been generated at a mid-ocean ridge via partial melting of mantle rock below as part of the seafloor spreading process, and that all of crustal basement rocks of today’s ocean floor were no older than Mesozoic in age. Among the implications were that the ...
Crustal structure of the southern margin of the African - ePIC
... [8] The offshore section of this western profile starts about 20 km off the coast and stretches over 400 km south, past the Agulhas-Falkland Fracture Zone (AFFZ, Figure 1). Between the AFFZ and the present coast a network of basins, collectively referred to as the Outeniqua Basin (Figure 1), is loca ...
... [8] The offshore section of this western profile starts about 20 km off the coast and stretches over 400 km south, past the Agulhas-Falkland Fracture Zone (AFFZ, Figure 1). Between the AFFZ and the present coast a network of basins, collectively referred to as the Outeniqua Basin (Figure 1), is loca ...
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.