Numerical Geodynamic Modeling of Continental Convergent Margins
... The continental convergence (subduction/collision) normally follows the oceanic subduction under the convergent forces of lateral ridge push and/or oceanic slab pull (Turcotte and Schubert, 2002). During these scenarios, a large amount of positively buoyant materials enter the trench causing slow do ...
... The continental convergence (subduction/collision) normally follows the oceanic subduction under the convergent forces of lateral ridge push and/or oceanic slab pull (Turcotte and Schubert, 2002). During these scenarios, a large amount of positively buoyant materials enter the trench causing slow do ...
The North Palawan Block, Philippines
... Upper Miocene to Recent carbonates, developed peripherally to the main St. Paul's limestone buildup, point to a phase of late Mid-Miocene uplift and nondeposition corresponding to that found in offshore areas (see below). Igneous rocks in northern Palawan are chiefly represented by two quartz monzon ...
... Upper Miocene to Recent carbonates, developed peripherally to the main St. Paul's limestone buildup, point to a phase of late Mid-Miocene uplift and nondeposition corresponding to that found in offshore areas (see below). Igneous rocks in northern Palawan are chiefly represented by two quartz monzon ...
Investigating Large Igneous Province Formation and
... dynamic processes, with unclear relationships to seafloor spreading and subduction, generated voluminous,��������� predominately mafic magmas that were emplaced into the �������� E������� arth’s lithosphere. The resultant large�������������������������� igneous provinces (LIPs; Coffin and Eldholm, 1 ...
... dynamic processes, with unclear relationships to seafloor spreading and subduction, generated voluminous,��������� predominately mafic magmas that were emplaced into the �������� E������� arth’s lithosphere. The resultant large�������������������������� igneous provinces (LIPs; Coffin and Eldholm, 1 ...
2D finite element modeling
... melange belts (McHugh Complex and Iceworm melamges) in the Chugach convergent margin, central-south Alaska. The accretionary prism is assumed to be elastic continuum. The subduction of the Pacific plate beneath the North American plate and the underplating of the oceanic crust is subjected as the bou ...
... melange belts (McHugh Complex and Iceworm melamges) in the Chugach convergent margin, central-south Alaska. The accretionary prism is assumed to be elastic continuum. The subduction of the Pacific plate beneath the North American plate and the underplating of the oceanic crust is subjected as the bou ...
Conserving California`s Vibrant Deep-Sea Ecosystems
... ridges and banks that host spectacularly diverse marine wildlife and habitats, as well as extraordinary geological features. These areas serve as oceanic oases, providing nutrient-rich waters, unusually high productivity and relatively large concentrations of sea life. Endangered sperm, fin and blue ...
... ridges and banks that host spectacularly diverse marine wildlife and habitats, as well as extraordinary geological features. These areas serve as oceanic oases, providing nutrient-rich waters, unusually high productivity and relatively large concentrations of sea life. Endangered sperm, fin and blue ...
Center for Geomicrobiology, Aarhus University, 2007-2012
... cells of the deep biosphere are essentially non-growing with apparent mean generation times of hundreds to thousands of years. In spite of their slow life, these microorganisms drive major processes in the geosphere and control element cycles that affect hydrocarbon reservoirs, ocean chemistry, and g ...
... cells of the deep biosphere are essentially non-growing with apparent mean generation times of hundreds to thousands of years. In spite of their slow life, these microorganisms drive major processes in the geosphere and control element cycles that affect hydrocarbon reservoirs, ocean chemistry, and g ...
HMS Challenger NHD Essay FINAL COPY
... layers” at one point in the Atlantic (see Appendix D).48 Afterwards, the Challenger also found these rocks in other oceans, especially in the Pacific. 49 The Challenger exposed these curious rocks to the world for the first time.50 Modern scientists have named these rocks manganese nodules, which ar ...
... layers” at one point in the Atlantic (see Appendix D).48 Afterwards, the Challenger also found these rocks in other oceans, especially in the Pacific. 49 The Challenger exposed these curious rocks to the world for the first time.50 Modern scientists have named these rocks manganese nodules, which ar ...
Anomalously thin transition zone and apparently isotropic upper
... structure along a line across the southern Bermuda rise and found the crust is approximately 1.5 km thinner than the smoother (150–450 m relief) and rapidly formed (13–14 mm/a) crust to the west. Vogt and Jung [2007] point out that, however, that even if lithospheric control plays a role, it does no ...
... structure along a line across the southern Bermuda rise and found the crust is approximately 1.5 km thinner than the smoother (150–450 m relief) and rapidly formed (13–14 mm/a) crust to the west. Vogt and Jung [2007] point out that, however, that even if lithospheric control plays a role, it does no ...
PDF Version - Bullard Laboratories
... influenced by the behaviour of the Iceland Plume, whose striking dominance is manifest by long-wavelength free-air gravity anomalies and by oceanic bathymetric anomalies. Here, we use these anomalies to estimate the amplitude and wavelength of present-day dynamic uplift associated with this plume. M ...
... influenced by the behaviour of the Iceland Plume, whose striking dominance is manifest by long-wavelength free-air gravity anomalies and by oceanic bathymetric anomalies. Here, we use these anomalies to estimate the amplitude and wavelength of present-day dynamic uplift associated with this plume. M ...
Chemical Geodynamics
... the Earth’s structure is derived from geochemical inference, because geophysics only samples the present (exception: paleomag) • However, geochemistry only samples the surface, so inferences about depths within the Earth are indirect, and must be supplemented by geological or geophysical constraints ...
... the Earth’s structure is derived from geochemical inference, because geophysics only samples the present (exception: paleomag) • However, geochemistry only samples the surface, so inferences about depths within the Earth are indirect, and must be supplemented by geological or geophysical constraints ...
Photosynthesis in the Ocean as a Function of Light Intensity
... with terrestrial or freshwater plants have not been concerned with the high intensities at which this inhibition occurs, but the phenomenon has been clearly demonstrated in all measurements of photosynthesis in natural waters by a marked depression at or near the surface where the organisms are expo ...
... with terrestrial or freshwater plants have not been concerned with the high intensities at which this inhibition occurs, but the phenomenon has been clearly demonstrated in all measurements of photosynthesis in natural waters by a marked depression at or near the surface where the organisms are expo ...
Downloaded
... The availability of nutrients in the oceans and their means of supply vary considerably from one region to another due largely to differences in physical characteristics. For example, approximately 25 per cent of the ocean surface has consistently high concentrations of macronutrients but still the ...
... The availability of nutrients in the oceans and their means of supply vary considerably from one region to another due largely to differences in physical characteristics. For example, approximately 25 per cent of the ocean surface has consistently high concentrations of macronutrients but still the ...
1 2 Fifteen years of ocean observations with the global Argo array 3
... with little or no correction required. The other 20% of the data are corrected using delayed-mode quality control ...
... with little or no correction required. The other 20% of the data are corrected using delayed-mode quality control ...
Becker, T. W. - The University of Texas at Austin
... The long-term stress-state of the lithosphere results from a combination of boundary forces, surface loads and tractions from mantle flow. Here, we have employed a numerical technique which allows for the selfconsistent treatment of the interaction between the lithosphere and mantle and takes into a ...
... The long-term stress-state of the lithosphere results from a combination of boundary forces, surface loads and tractions from mantle flow. Here, we have employed a numerical technique which allows for the selfconsistent treatment of the interaction between the lithosphere and mantle and takes into a ...
Geochemistry of mafic rocks and melt inclusions and their
... degree of mantle partial melting. Instead, several small-scale magma intrusions commonly occurred within the crust (Mccaig and Harris, 2012). The lack of a steady-state magma chamber makes it difficult to form corresponding hydrothermal systems. However, once a hydrothermal system was formed in this ...
... degree of mantle partial melting. Instead, several small-scale magma intrusions commonly occurred within the crust (Mccaig and Harris, 2012). The lack of a steady-state magma chamber makes it difficult to form corresponding hydrothermal systems. However, once a hydrothermal system was formed in this ...
SiphonPaper_TextOnly_141124 - UC Santa Cruz
... *Correspondence to: [email protected] Abstract: Most seafloor hydrothermal circulation occurs far from the magmatic influence of mid-ocean ridges, driving large flows of water, heat and solutes through volcanic rock outcrops on ridge flanks. We created three-dimensional simulations of ridge-flank hy ...
... *Correspondence to: [email protected] Abstract: Most seafloor hydrothermal circulation occurs far from the magmatic influence of mid-ocean ridges, driving large flows of water, heat and solutes through volcanic rock outcrops on ridge flanks. We created three-dimensional simulations of ridge-flank hy ...
Imag(in)ing the continental lithosphere
... receiver functions from earthquakes at a range of distances. The much lower frequency receiver functions see converted wave events from the layering observed in the mantle in the higher frequency reflection data. This section illustrates that mantle features are observable over a broad bandwidth, an ...
... receiver functions from earthquakes at a range of distances. The much lower frequency receiver functions see converted wave events from the layering observed in the mantle in the higher frequency reflection data. This section illustrates that mantle features are observable over a broad bandwidth, an ...
Fifteen years of ocean observations with the global Argo array
... with fresh areas getting fresher and salty areas becoming more saline, is consistent with an overall net increase ...
... with fresh areas getting fresher and salty areas becoming more saline, is consistent with an overall net increase ...
Acoustic study of the Rıo de la Plata estuarine front
... a plane interface was calculated (Clay and Medwin, 1977). Further, a comparison was made between the in situ measured area backscattering strength (Sa), and the hypothetical Sa. Theoretical values were estimated from the abundance of different plankton groups and employing sound-scattering models, as ...
... a plane interface was calculated (Clay and Medwin, 1977). Further, a comparison was made between the in situ measured area backscattering strength (Sa), and the hypothetical Sa. Theoretical values were estimated from the abundance of different plankton groups and employing sound-scattering models, as ...
Mechanisms of lithospheric extension at mid
... Accepted 1988 June 11. Received 1988 June 11; in original form 1987 September 9 ...
... Accepted 1988 June 11. Received 1988 June 11; in original form 1987 September 9 ...
Potential for deep sea invasion by Mediterranean shallow water
... invasion of the deep sea by shallow water species; Hessler & Wilson (1983) have identified substratum type, pressure, light, and nutrient availability as other probable llmiting factors. Physiological adaptation to high pressure has been recently reviewed by Somero (1992) and Somero et al. (1983).In ...
... invasion of the deep sea by shallow water species; Hessler & Wilson (1983) have identified substratum type, pressure, light, and nutrient availability as other probable llmiting factors. Physiological adaptation to high pressure has been recently reviewed by Somero (1992) and Somero et al. (1983).In ...
A selfconsistent model of melting, magma migration and
... ters wide. All ridgesshow morphologicalvariations along The conclusionis that the parental liquids are not in equilistrike, but thesevariationsare more pronounced in slower brium with a harzburgite residue until the pressure is ...
... ters wide. All ridgesshow morphologicalvariations along The conclusionis that the parental liquids are not in equilistrike, but thesevariationsare more pronounced in slower brium with a harzburgite residue until the pressure is ...
Plate tectonics - Wikipedia, the free encyclopedia
... surface radiated like a black body.[5] Those calculations implied that, even if it started at red heat, the Earth would have dropped to its present temperature in a few tens of millions of years. Armed with the knowledge of a new heat source, scientists reasoned it was credible that the Earth was mu ...
... surface radiated like a black body.[5] Those calculations implied that, even if it started at red heat, the Earth would have dropped to its present temperature in a few tens of millions of years. Armed with the knowledge of a new heat source, scientists reasoned it was credible that the Earth was mu ...
Slab pull, mantle convection, and Pangaean assembly and dispersal
... that convergent margins become dormant, are reused at a later time, and that lithosphere- (and perhaps asthenosphere-) scale weaknesses might survive on time scales of 100 Myr or more [20]. This does not provide a reason for establishment of subduction zones; it merely suggests that once established ...
... that convergent margins become dormant, are reused at a later time, and that lithosphere- (and perhaps asthenosphere-) scale weaknesses might survive on time scales of 100 Myr or more [20]. This does not provide a reason for establishment of subduction zones; it merely suggests that once established ...
Coupled and decoupled regimes of continental collision: Numerical
... distribution of stresses (i.e., compressional in the foreland and extensional in the inner part of the orogen, Northern Apennines). In order to understand physical controls defining these different geodynamic regimes we conducted a 2D numerical study based on finite-differences and marker-in-cell tech ...
... distribution of stresses (i.e., compressional in the foreland and extensional in the inner part of the orogen, Northern Apennines). In order to understand physical controls defining these different geodynamic regimes we conducted a 2D numerical study based on finite-differences and marker-in-cell tech ...
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.