Hotspots and Melting Anomalies - Earth and Environmental Sciences
... Hekinian et al., 2004). Alternative mechanisms, which emphasize asthenosphere and lithospheric processes, are being re-evaluated and some new ones proposed (Foulger et al., 2005). It has become clear that few hotspots confidently show all of the above characteristics of the classic description. The ...
... Hekinian et al., 2004). Alternative mechanisms, which emphasize asthenosphere and lithospheric processes, are being re-evaluated and some new ones proposed (Foulger et al., 2005). It has become clear that few hotspots confidently show all of the above characteristics of the classic description. The ...
Submarine cables and the oceans - International Cable Protection
... and the International Cable Protection Committee (ICPC), which represents the majority of ocean users within the submarine telecommunications cable industry. Why is such a report required? The last 20 years have seen exponential growth of and increasing reliance on the internet for communication, co ...
... and the International Cable Protection Committee (ICPC), which represents the majority of ocean users within the submarine telecommunications cable industry. Why is such a report required? The last 20 years have seen exponential growth of and increasing reliance on the internet for communication, co ...
The stability of arc lower crust: Insights from the Talkeetna Arc
... examined only end member water saturated MORB and ultramafic compositions and did not explore the influence of intermediate water contents or variations in major element composition on the density and seismic velocity of the lower crust. Finally, none of these studies investigated the influence of o ...
... examined only end member water saturated MORB and ultramafic compositions and did not explore the influence of intermediate water contents or variations in major element composition on the density and seismic velocity of the lower crust. Finally, none of these studies investigated the influence of o ...
Marine particle dynamics: sinking velocities, size
... The sinking flux of particulate matter into the ocean interior is an oceanographic phenomenon that fuels much of the metabolic demand of the subsurface ocean and affects the distribution of carbon and other elements throughout the biosphere. In this thesis, I use a new suite of observations to study ...
... The sinking flux of particulate matter into the ocean interior is an oceanographic phenomenon that fuels much of the metabolic demand of the subsurface ocean and affects the distribution of carbon and other elements throughout the biosphere. In this thesis, I use a new suite of observations to study ...
Melt migration beneath mid-ocean ridges
... has yet to be determined and it is still not clear whether the pressure gradient arising from mantle £ow with a viscosity of less than 1021 Pa s is su¤cient to direct melt towards the ridge. The third theory considers the partially molten upper mantle as a reactive, permeable compacting/decompacting ...
... has yet to be determined and it is still not clear whether the pressure gradient arising from mantle £ow with a viscosity of less than 1021 Pa s is su¤cient to direct melt towards the ridge. The third theory considers the partially molten upper mantle as a reactive, permeable compacting/decompacting ...
Lithosphere delamination in continental collisional orogens: A
... processes that thickened the crust should have also thickened the mantle lithosphere. The examples include many orogens in the Alpine-Himalayan collisional belt such as the Tibetan Plateau [Bird, 1978; Jimenez-Munt et al., 2008], the Anatolia [Keskin, 2003; Gogus and Pysklywec, 2008a], the Apennines ...
... processes that thickened the crust should have also thickened the mantle lithosphere. The examples include many orogens in the Alpine-Himalayan collisional belt such as the Tibetan Plateau [Bird, 1978; Jimenez-Munt et al., 2008], the Anatolia [Keskin, 2003; Gogus and Pysklywec, 2008a], the Apennines ...
Hawaii, Boundary Layers and Ambient
... recycling bin. Part of the reason for this focus on D’’, rather than the shallow mantle, is the perception that the whole upper mantle is homogeneous and can provide only depleted mid-ocean ridge basalts (MORB), and that D’’ is isolated from ‘the convecting mantle’. To focus attention on the upper m ...
... recycling bin. Part of the reason for this focus on D’’, rather than the shallow mantle, is the perception that the whole upper mantle is homogeneous and can provide only depleted mid-ocean ridge basalts (MORB), and that D’’ is isolated from ‘the convecting mantle’. To focus attention on the upper m ...
Kerguelen Hotspot Magma Output since 130 Ma
... crustal volumes of the various age provinces. Similarly, for those portions of the Kerguelen LIP that formed predominantly within oceanic lithosphere, we have subtracted a layer 7·1 km thick (White et al., 1992). In this respect, our study resembles the approaches of White (1993) and Saunders et al. ...
... crustal volumes of the various age provinces. Similarly, for those portions of the Kerguelen LIP that formed predominantly within oceanic lithosphere, we have subtracted a layer 7·1 km thick (White et al., 1992). In this respect, our study resembles the approaches of White (1993) and Saunders et al. ...
Bioprospecting of Genetic Resources in the Deep Seabed
... which have developed unique biological and physiological properties to survive in extreme environmental conditions. These species, called extremophiles, are found in areas such as Antarctica and the deep seabed. In the absence of an internationally-agreed definition of the term “deep seabed,” this re ...
... which have developed unique biological and physiological properties to survive in extreme environmental conditions. These species, called extremophiles, are found in areas such as Antarctica and the deep seabed. In the absence of an internationally-agreed definition of the term “deep seabed,” this re ...
Oxygen Sensitivity of Anammox and Coupled N
... circulation results in the upwelling of nutrient-rich deep waters, fueling high primary production in the euphotic zone. The high surface productivity results in high export of organic matter and thus strong respiration in subsurface waters. Combined with the poor ventilation of these water masses [ ...
... circulation results in the upwelling of nutrient-rich deep waters, fueling high primary production in the euphotic zone. The high surface productivity results in high export of organic matter and thus strong respiration in subsurface waters. Combined with the poor ventilation of these water masses [ ...
Mapping the Moho with seismic surface waves: A review, resolution
... period and indicative of the increase of elastic velocities with depth. He also inferred different crustal thicknesses for Eurasia, America and the Atlantic and Pacific Oceans. Testing crustal thicknesses of 30, 60 and 120 km, he estimated the crustal thickness for Eurasia to be around 50 km. This wa ...
... period and indicative of the increase of elastic velocities with depth. He also inferred different crustal thicknesses for Eurasia, America and the Atlantic and Pacific Oceans. Testing crustal thicknesses of 30, 60 and 120 km, he estimated the crustal thickness for Eurasia to be around 50 km. This wa ...
Global geochemical variation of mid-ocean ridge basalts - UiO
... 1.1. A brief introduction to MORB and mantle geochemistry The mid ocean ridges (MORs) are the Earth’s longest mountain chain and are present at all divergent plate boundaries. At the MORs the lithosphere that gets recycled into the mantle at the subduction zones, their plate tectonical counterparts, ...
... 1.1. A brief introduction to MORB and mantle geochemistry The mid ocean ridges (MORs) are the Earth’s longest mountain chain and are present at all divergent plate boundaries. At the MORs the lithosphere that gets recycled into the mantle at the subduction zones, their plate tectonical counterparts, ...
Spatial and temporal variability of surface water pCO2 and sampling
... concentration caused by winter convective mixing of deep waters rich in CO2. It is therefore the interactions of the three major effects (i. e. temperature, upwelling and biological utilization of CO2) that determine the annual mean pCO2 and variability about the mean in space and time. Variability ...
... concentration caused by winter convective mixing of deep waters rich in CO2. It is therefore the interactions of the three major effects (i. e. temperature, upwelling and biological utilization of CO2) that determine the annual mean pCO2 and variability about the mean in space and time. Variability ...
Dynamical geochemistry of the mantle
... with smaller proportions of eclogite and pyroxenite (Ringwood, 1975; Hofmann, 1997). With the advent of plate tectonics a straightforward explanation for this became evident: a subducting plate is a layered structure, with mafic oceanic crust on top and an ultramafic (peridotite) mantle section unde ...
... with smaller proportions of eclogite and pyroxenite (Ringwood, 1975; Hofmann, 1997). With the advent of plate tectonics a straightforward explanation for this became evident: a subducting plate is a layered structure, with mafic oceanic crust on top and an ultramafic (peridotite) mantle section unde ...
UNOLS Booth at 2014 Ocean Sciences Conference Program
... Limnology and Oceanography poster presenters to be available to talk about their is not allowed at the meeting. For more than 50 years, ASLO has been a leadposters have been scheduled between 16:00 and ing professional organization for researchers and Thank you for your cooperation. 18:00 on Monday ...
... Limnology and Oceanography poster presenters to be available to talk about their is not allowed at the meeting. For more than 50 years, ASLO has been a leadposters have been scheduled between 16:00 and ing professional organization for researchers and Thank you for your cooperation. 18:00 on Monday ...
Geophysical and Petrological Constraints on Ocean Plate Dynamics
... that the oceanic mantle potential temperature must be ~60 ºC hotter than current estimates. Chapter 3 goes further to provide a more accurate parameterization of the anhydrous mantle solidus from experiments over a range of pressures. This chapter concludes that the range of potential temperatures o ...
... that the oceanic mantle potential temperature must be ~60 ºC hotter than current estimates. Chapter 3 goes further to provide a more accurate parameterization of the anhydrous mantle solidus from experiments over a range of pressures. This chapter concludes that the range of potential temperatures o ...
PDF
... bottom to top) from less to more HFSE-depleted and LILEenriched compositions and (a) generally comprise a lower, usually MORB/FAB unit and an upper VAB unit, sometimes along with boninites, both of which (b) form in a proto-forearc setting during subduction initiation (Fig. 2). An exception to this ...
... bottom to top) from less to more HFSE-depleted and LILEenriched compositions and (a) generally comprise a lower, usually MORB/FAB unit and an upper VAB unit, sometimes along with boninites, both of which (b) form in a proto-forearc setting during subduction initiation (Fig. 2). An exception to this ...
Anderson and Natland, 2005
... Plate tectonics was developed during the 1960s and 1970s as a kinematic and descriptive theory that involved such idealizations as rigid (or elastic) and permanent plates, sharp plate boundaries, uniform isothermal mantle, homogeneous plates, and steady-state conditions. Diffuse plate boundaries, vo ...
... Plate tectonics was developed during the 1960s and 1970s as a kinematic and descriptive theory that involved such idealizations as rigid (or elastic) and permanent plates, sharp plate boundaries, uniform isothermal mantle, homogeneous plates, and steady-state conditions. Diffuse plate boundaries, vo ...
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... zone, implying that Kohistan and India moved northwards on the same plate, although separated, during much of Cretaceous time. Collision of Kohistan with the Karakorum caused a new, north-dipping subduction zone to form on the south side of Kohistan, leading to collision with India in early Tertiary ...
... zone, implying that Kohistan and India moved northwards on the same plate, although separated, during much of Cretaceous time. Collision of Kohistan with the Karakorum caused a new, north-dipping subduction zone to form on the south side of Kohistan, leading to collision with India in early Tertiary ...
thrust systems - The Web site cannot be found
... topography upwards, creating a mountain defined as a landform higher than the neighbouring area. Mountain building is a complex process, termed orogeny. The presence of mountains as physiographic features of orogenic belts (or simply orogens) is not integral expression of an orogeny. Erosion levelle ...
... topography upwards, creating a mountain defined as a landform higher than the neighbouring area. Mountain building is a complex process, termed orogeny. The presence of mountains as physiographic features of orogenic belts (or simply orogens) is not integral expression of an orogeny. Erosion levelle ...
The Seismic Structure of Island Arc Crust
... (<50–100 km), because they are mostly first arrivals. P wave velocity models can be derived by tomographic inversion of first arrival travel times alone, and although there are a variety of approaches, those methods frequently used in crustal seismology produce velocity models that vary smoothly bot ...
... (<50–100 km), because they are mostly first arrivals. P wave velocity models can be derived by tomographic inversion of first arrival travel times alone, and although there are a variety of approaches, those methods frequently used in crustal seismology produce velocity models that vary smoothly bot ...
workshop report
... most was originally created by obscure processes in the Hadean (e.g., Armstrong, 1968) and that some has been created from plume heads in Large Igneous Provinces (Bath et al., 2000), neither of these hypotheses can be tested by drilling, so we will focus solely on the role of subduction in creating ...
... most was originally created by obscure processes in the Hadean (e.g., Armstrong, 1968) and that some has been created from plume heads in Large Igneous Provinces (Bath et al., 2000), neither of these hypotheses can be tested by drilling, so we will focus solely on the role of subduction in creating ...
state of knowledge of the geothermal provinces of the
... the collapse of the ground. Locally small anomalies could be the result of an intensively fractured zone. The comparison with the aeromagnetic data and the gravimetric modelling, with the help of geothermal data, demonstrate the existence of a basement represented by the old Dalha basalt series, spl ...
... the collapse of the ground. Locally small anomalies could be the result of an intensively fractured zone. The comparison with the aeromagnetic data and the gravimetric modelling, with the help of geothermal data, demonstrate the existence of a basement represented by the old Dalha basalt series, spl ...
Origin and consequences of western Mediterranean subduction
... et al. [2011] and van Hinsbergen and Schmid [2012]. Most importantly, our reconstruction allows for burial of sediments that are now metamorphosed (i.e., units disappear from the surface) and their subsequent exhumation (i.e., units reappear to the surface). This approach differs from recent reconst ...
... et al. [2011] and van Hinsbergen and Schmid [2012]. Most importantly, our reconstruction allows for burial of sediments that are now metamorphosed (i.e., units disappear from the surface) and their subsequent exhumation (i.e., units reappear to the surface). This approach differs from recent reconst ...
the Zero Paradox Noble Gas Mantle
... layered model of the mantle in which a shallow well mixed, volatile poor and depleted reservoir supplies mid ocean ridge volcanism. In this model plumes feed intraplate volcanism from the deep mantle and sample a more volatile rich and less depleted portion of the mantle. The boundary between these ...
... layered model of the mantle in which a shallow well mixed, volatile poor and depleted reservoir supplies mid ocean ridge volcanism. In this model plumes feed intraplate volcanism from the deep mantle and sample a more volatile rich and less depleted portion of the mantle. The boundary between these ...
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.