Lecture Notes Part 1
... for its density to reach a critical value -this situation is found at high latitudes, in particular near Greenland and Antarctica -at these sites, cold air temperature during winter cools surface water (typically to < 2ºC) which, in turn, increases its density -surface waters during winter in these ...
... for its density to reach a critical value -this situation is found at high latitudes, in particular near Greenland and Antarctica -at these sites, cold air temperature during winter cools surface water (typically to < 2ºC) which, in turn, increases its density -surface waters during winter in these ...
Convergent-Boundary Mountains
... mountain ranges. • Orogeny results in broad, linear regions of deformation known as orogenic belts, most of which are associated with plate boundaries. • Convergent boundaries are the location of the greatest variety and the tallest orogenic belts. • The compressive forces at these boundaries may ca ...
... mountain ranges. • Orogeny results in broad, linear regions of deformation known as orogenic belts, most of which are associated with plate boundaries. • Convergent boundaries are the location of the greatest variety and the tallest orogenic belts. • The compressive forces at these boundaries may ca ...
Subduction of young oceanic plates: A numerical study with
... geophysical characteristics of subduction zones are varied and controlled by factors like plate velocity, direction and angle of convergence, thickness and age of the lithosphere, convection in the overlying mantle wedge, fluids and melts migrating through the subduction zone, and time [e.g., Kirby ...
... geophysical characteristics of subduction zones are varied and controlled by factors like plate velocity, direction and angle of convergence, thickness and age of the lithosphere, convection in the overlying mantle wedge, fluids and melts migrating through the subduction zone, and time [e.g., Kirby ...
Diamonds in Ophiolites
... The chromite grains and perhaps some small chromitites carrying diamonds appear to have formed at or near the top of the mantle transition zone. The presence of many silicate minerals, such as zircon, corundum, kyanite, and rutile in ophiolitic chromitites and peridotites (Robinson et al. 2011; Yam ...
... The chromite grains and perhaps some small chromitites carrying diamonds appear to have formed at or near the top of the mantle transition zone. The presence of many silicate minerals, such as zircon, corundum, kyanite, and rutile in ophiolitic chromitites and peridotites (Robinson et al. 2011; Yam ...
Isotopic Tracers of the Marine Nitrogen Cycle: Present and Past
... The principal loci for denitrification in the ocean are regions with suboxic intermediate waters (water column denitrification) and continental margin sediments (sediment denitrification; e.g. [27]). Water column denitrification occurs primarily in three locations; the Arabian Sea [28], the Eastern Trop ...
... The principal loci for denitrification in the ocean are regions with suboxic intermediate waters (water column denitrification) and continental margin sediments (sediment denitrification; e.g. [27]). Water column denitrification occurs primarily in three locations; the Arabian Sea [28], the Eastern Trop ...
IBAC Technical Report Summary - International Business Aviation
... FIR will be addressed in the Caribbean and South American (CAR/SAM) ANP and in the CAR SUPPs. It was indicated that the amendment was expected to be effective before the end of 2013. The ATMG was presented with information on a PfA to PANS-ATM (Doc 4444) section 15.8 subsequent to a recommendation ...
... FIR will be addressed in the Caribbean and South American (CAR/SAM) ANP and in the CAR SUPPs. It was indicated that the amendment was expected to be effective before the end of 2013. The ATMG was presented with information on a PfA to PANS-ATM (Doc 4444) section 15.8 subsequent to a recommendation ...
Spreading Continents Kick-Started Plate Tectonics Plate tectonics
... onset of plate tectonics require that convective stresses overcame the strength of the stagnant lid12 at ...
... onset of plate tectonics require that convective stresses overcame the strength of the stagnant lid12 at ...
Ecosystems and Biodiversity in Deep Waters and High Seas
... a long and successful history in working with states and stakeholders on marine and ocean issues. The missions of our respective organisations are “to provide leadership and encourage partnership in caring for the environment by inspiring, informing, and enabling nations and peoples to improve their ...
... a long and successful history in working with states and stakeholders on marine and ocean issues. The missions of our respective organisations are “to provide leadership and encourage partnership in caring for the environment by inspiring, informing, and enabling nations and peoples to improve their ...
Isostasy
... Isostasy: – State of hydrostatic equilibrium where the weight of columns of rock, at some depth called the depth of compensation, is everywhere equal. – Isostasy can be achieved by: • Varying crustal density laterally (Pratt model) • Varying crustal thickness laterally (Airy model) ...
... Isostasy: – State of hydrostatic equilibrium where the weight of columns of rock, at some depth called the depth of compensation, is everywhere equal. – Isostasy can be achieved by: • Varying crustal density laterally (Pratt model) • Varying crustal thickness laterally (Airy model) ...
Subduction factory 2. Are intermediate
... include any intraslab event shallower than 300 km and downdip from the thrust zone. Such earthquakes are frequent and damaging in some subduction zones (e.g., the MS = 7.8 El Salvador earthquake of 13 January 2001, which killed >1200 people), such that understanding and predicting their distribution ...
... include any intraslab event shallower than 300 km and downdip from the thrust zone. Such earthquakes are frequent and damaging in some subduction zones (e.g., the MS = 7.8 El Salvador earthquake of 13 January 2001, which killed >1200 people), such that understanding and predicting their distribution ...
PDF (Chapter 3. The Crust and Upper Mantle)
... and the spread is about 7.9-8.6 kmls. Some long refraction profiles give evidence for a deeper layer in the lithosphere having a velocity of 8.6 km/s. The seismic lithosphere, or LID, appears to contain at least two layers. Long refraction profiles on continents have been interpreted in terms of a l ...
... and the spread is about 7.9-8.6 kmls. Some long refraction profiles give evidence for a deeper layer in the lithosphere having a velocity of 8.6 km/s. The seismic lithosphere, or LID, appears to contain at least two layers. Long refraction profiles on continents have been interpreted in terms of a l ...
Geodynamical interpretation of crustal and upper mantle electrical conductivity
... drops towards the north-eastern segment of the rift zone (see profile SS1 Fig. 1) and attenuation rate varies both vertically and horizontally. There is a high absorption layer contacting the crustal base that is underlain in the central part of the rift by low-absorption rocks. The high absorptive ...
... drops towards the north-eastern segment of the rift zone (see profile SS1 Fig. 1) and attenuation rate varies both vertically and horizontally. There is a high absorption layer contacting the crustal base that is underlain in the central part of the rift by low-absorption rocks. The high absorptive ...
Upper mantle
... Lower mantle beneath cratons (Brazil; Africa) colder (higher P wave vel.) Pacific ocean; hotter- slower velocities Mid-Atlantic ridge: hot down to 400 km Dipping slabs beneath Japan and S. America visible at depth Lower mantle cold slaps also visible- favors single layer convection ...
... Lower mantle beneath cratons (Brazil; Africa) colder (higher P wave vel.) Pacific ocean; hotter- slower velocities Mid-Atlantic ridge: hot down to 400 km Dipping slabs beneath Japan and S. America visible at depth Lower mantle cold slaps also visible- favors single layer convection ...
Genesis of Ultra-High Pressure Garnet Pyroxenite in Orogenic
... by garnet pyroxenites in orogenic peridotites—- intimately mixed with peridotites by mantle convection. The present study reveals, however, that besides this exotic component of ancient recycled oceanic crust, the genesis of these pyroxenites requires a previously unnoticed component of recycled low ...
... by garnet pyroxenites in orogenic peridotites—- intimately mixed with peridotites by mantle convection. The present study reveals, however, that besides this exotic component of ancient recycled oceanic crust, the genesis of these pyroxenites requires a previously unnoticed component of recycled low ...
Davis, E. E., and Fisher, A. T., Seafloor heat flow
... Page Number: 0 Date:24/8/10 Time:12:05:45 ...
... Page Number: 0 Date:24/8/10 Time:12:05:45 ...
Evidence for mantle metasomatism by hydrous silicic - HAL-Insu
... Extensive garnet crystallization at 30 kbar also lowers the Al2O3 content of the glasses relative to those at 20 kbar (Table 1). In the CaO versus Na2O diagram (Fig. 2), all glasses so far produced in H2O-added melting experiments on basalts up to 30 kbar 11-13 display a broad negative trend that co ...
... Extensive garnet crystallization at 30 kbar also lowers the Al2O3 content of the glasses relative to those at 20 kbar (Table 1). In the CaO versus Na2O diagram (Fig. 2), all glasses so far produced in H2O-added melting experiments on basalts up to 30 kbar 11-13 display a broad negative trend that co ...
Thermal structure and intermediate-depth seismicity in the Tohoku
... Received: 23 July 2012 – Published in Solid Earth Discuss.: 6 August 2012 Revised: 2 October 2012 – Accepted: 10 October 2012 – Published: 7 November 2012 ...
... Received: 23 July 2012 – Published in Solid Earth Discuss.: 6 August 2012 Revised: 2 October 2012 – Accepted: 10 October 2012 – Published: 7 November 2012 ...
Programme - The Future Ocean
... influenced by the optical properties of the water (i.e. light absorption and scattering) and direct reflections at the atmosphere/ocean interface. Optical influences of the relatively thin surface microlayer (SML) on the ocean’s surface reflectance are expected to be very low. However, validation of ...
... influenced by the optical properties of the water (i.e. light absorption and scattering) and direct reflections at the atmosphere/ocean interface. Optical influences of the relatively thin surface microlayer (SML) on the ocean’s surface reflectance are expected to be very low. However, validation of ...
IMBER Update
... Figure 2. MODIS Chlorophyll image composite for the period October 29-31, 2006 showing the strong phytoplankton blooms which usually occur in Austral spring time along the Patagonia shelf-break area. During this period, 26 oceanographic stations (+) were occupied in the area with the collection of p ...
... Figure 2. MODIS Chlorophyll image composite for the period October 29-31, 2006 showing the strong phytoplankton blooms which usually occur in Austral spring time along the Patagonia shelf-break area. During this period, 26 oceanographic stations (+) were occupied in the area with the collection of p ...
SiphonPaper_Supplement_141124
... siphon flow rates and cooling within the upper crustal aquifer exceeding observations at the field site (kaq ≥ 10-11 m2). In-situ bulk permeability determinations made in basaltic ocean crust, using an inflatable packer or a temperature log in an unsealed hole, indicate permeability in the upper 30 ...
... siphon flow rates and cooling within the upper crustal aquifer exceeding observations at the field site (kaq ≥ 10-11 m2). In-situ bulk permeability determinations made in basaltic ocean crust, using an inflatable packer or a temperature log in an unsealed hole, indicate permeability in the upper 30 ...
Occurrences of disseminated sulphides from
... The NCIR is characterised by short-ridge segments and long transform geometry (maximum displacement at the Vema transform fault is ~243 km). The depth of the seafloor including the axial valley, transform fault, and outer ridge flank of the NCIR varies from 1,500 to 6,500 m. The adjacent morphology ...
... The NCIR is characterised by short-ridge segments and long transform geometry (maximum displacement at the Vema transform fault is ~243 km). The depth of the seafloor including the axial valley, transform fault, and outer ridge flank of the NCIR varies from 1,500 to 6,500 m. The adjacent morphology ...
Subduction factory 2. Are intermediate
... include any intraslab event shallower than 300 km and downdip from the thrust zone. Such earthquakes are frequent and damaging in some subduction zones (e.g., the MS = 7.8 El Salvador earthquake of 13 January 2001, which killed >1200 people), such that understanding and predicting their distribution ...
... include any intraslab event shallower than 300 km and downdip from the thrust zone. Such earthquakes are frequent and damaging in some subduction zones (e.g., the MS = 7.8 El Salvador earthquake of 13 January 2001, which killed >1200 people), such that understanding and predicting their distribution ...
rea proposta para extenso da plataforma
... The accuracy of the age grid varies considerably due to the spatially irregular distribution of ship track data in the oceans. Other sources of errors are given by our chosen spacing of isochrons as listed before, between which we interpolated linearly. These stages are especially long during long t ...
... The accuracy of the age grid varies considerably due to the spatially irregular distribution of ship track data in the oceans. Other sources of errors are given by our chosen spacing of isochrons as listed before, between which we interpolated linearly. These stages are especially long during long t ...
Southwest U.S. Region Mountain
... Its subduction built most of the North American Cordillera, bunching up the west end of the North American plate like folds It is also the origin of the Sierra Nevada Batholith via subduction under North America ...
... Its subduction built most of the North American Cordillera, bunching up the west end of the North American plate like folds It is also the origin of the Sierra Nevada Batholith via subduction under North America ...
41. Regional Synthesis of the Deep Sea Drilling Results from Leg 22
... The first three sites were chosen to investigate the sedimentary structure and age of the Wharton Basin. At Site 211 the acoustically transparent sediments were sampled south of the Sunda Trench and the age of the north central portion of the basin was also determined. Site 212 was drilled in a deep ...
... The first three sites were chosen to investigate the sedimentary structure and age of the Wharton Basin. At Site 211 the acoustically transparent sediments were sampled south of the Sunda Trench and the age of the north central portion of the basin was also determined. Site 212 was drilled in a deep ...
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.