Large Igneous Provinces, Delamination, and Fertile Mantle
... ductive cooling of the type associated with regular oceanic reconstructions (Müller et al. 1993) show that the currently crust. The North Atlantic Ocean is particularly shallow, but continent-hugging plateaus (~1000 km offshore) were modeling by Clift (2005) indicates that the depth is consis- mainl ...
... ductive cooling of the type associated with regular oceanic reconstructions (Müller et al. 1993) show that the currently crust. The North Atlantic Ocean is particularly shallow, but continent-hugging plateaus (~1000 km offshore) were modeling by Clift (2005) indicates that the depth is consis- mainl ...
Plate Tectonics and Landform Evolution
... envisaged the plate tectonic concept by formulating the hypothesis of continental drift at the beginning of the twentieth century. In his notable book Die Entstehung der Kontinente und Ozeane (1915), and in its numerous re-editions, he presented a total of 65 lines of evidence in favor of the existe ...
... envisaged the plate tectonic concept by formulating the hypothesis of continental drift at the beginning of the twentieth century. In his notable book Die Entstehung der Kontinente und Ozeane (1915), and in its numerous re-editions, he presented a total of 65 lines of evidence in favor of the existe ...
The Moho in subduction zones - Earth and Space Sciences at the
... nature of subduction zones implies the convergence of two plates, each characterized by a distinct Moho: one Moho associated with the incoming oceanic plate and another that may be of either continental or oceanic affinity. In this paper, we shall examine the processes operating in subduction zone fo ...
... nature of subduction zones implies the convergence of two plates, each characterized by a distinct Moho: one Moho associated with the incoming oceanic plate and another that may be of either continental or oceanic affinity. In this paper, we shall examine the processes operating in subduction zone fo ...
Simple Models of Diffuse Extension and the Pre
... higher hellt fl ow a nd subs idence rates during the time immediately following the exte nsional episode. Thus. during Ihis lime, a lower val ue of t3 would be required 10 match observed s ubsidence rates. depths or heal flow . After abo ut 10-1 5 m .y., however, it is probably not possible to d ist ...
... higher hellt fl ow a nd subs idence rates during the time immediately following the exte nsional episode. Thus. during Ihis lime, a lower val ue of t3 would be required 10 match observed s ubsidence rates. depths or heal flow . After abo ut 10-1 5 m .y., however, it is probably not possible to d ist ...
Oceanography - Flushing Community Schools
... Locate the Mid-Atlantic Ridge in Figure 1. Mid-ocean ridges can be found at the bottom of all ocean basins. They form a continuous underwater ridge approximately 70,000 km long. A mid-ocean ridge is the area in an ocean basin where new ocean floor is formed. Crustal plates, which are large sections ...
... Locate the Mid-Atlantic Ridge in Figure 1. Mid-ocean ridges can be found at the bottom of all ocean basins. They form a continuous underwater ridge approximately 70,000 km long. A mid-ocean ridge is the area in an ocean basin where new ocean floor is formed. Crustal plates, which are large sections ...
Davies, Nature, 1999 - Earth and Environmental Sciences
... Fig. 5. Distribution of H2O (left) and melt (right). (a) For a relatively cold slab (age 130 Myr) with a constant subduction velocity, of ~6 cm/year. A cross-sectional area of 250x250 km region with a fixed crust of 30 km thick is divided into a regular grid for numerical calculations, with a finer ...
... Fig. 5. Distribution of H2O (left) and melt (right). (a) For a relatively cold slab (age 130 Myr) with a constant subduction velocity, of ~6 cm/year. A cross-sectional area of 250x250 km region with a fixed crust of 30 km thick is divided into a regular grid for numerical calculations, with a finer ...
Large Igneous Provinces, Delamination, and Fertile Mantle
... mantle has a low melting point (FIG. 2) and can have slow seismic wave speeds (e.g. FIG. 3 in Anderson 1989a). It is usually assumed that these LVZs are related to the overlying volcanism and that they are thermal in nature. But some ancient LIPs, such as Paraná and the Ontong Java Plateau (OJP), re ...
... mantle has a low melting point (FIG. 2) and can have slow seismic wave speeds (e.g. FIG. 3 in Anderson 1989a). It is usually assumed that these LVZs are related to the overlying volcanism and that they are thermal in nature. But some ancient LIPs, such as Paraná and the Ontong Java Plateau (OJP), re ...
The Continental Drift Hypothesis Plate Tectonics
... By the 1960s, scientists had discovered a new process to help explain continental drift. This process is called seafloor spreading. Seafloor spreading is the process by which new oceanic crust forms along a mid-ocean ridge and older oceanic crust moves away from the ridge. When the seafloor spreads, ...
... By the 1960s, scientists had discovered a new process to help explain continental drift. This process is called seafloor spreading. Seafloor spreading is the process by which new oceanic crust forms along a mid-ocean ridge and older oceanic crust moves away from the ridge. When the seafloor spreads, ...
Oceanography
... Locate the Mid-Atlantic Ridge in Figure 1. Mid-ocean ridges can be found at the bottom of all ocean basins. They form a continuous underwater ridge approximately 70,000 km long. A mid-ocean ridge is the area in an ocean basin where new ocean floor is formed. Crustal plates, which are large sections ...
... Locate the Mid-Atlantic Ridge in Figure 1. Mid-ocean ridges can be found at the bottom of all ocean basins. They form a continuous underwater ridge approximately 70,000 km long. A mid-ocean ridge is the area in an ocean basin where new ocean floor is formed. Crustal plates, which are large sections ...
The deep subsurface biosphere in igneous ocean crust: frontier
... of RFH fluid is similar to the discharge of the global river system into the ocean; thus a volume equivalent to that of the global ocean is passed through the crust about once every 105 –106 years (e.g., Mottl and Wheat, 1994; Johnson and Pruis, 2003; Wheat et al., 2003). This is a very short residen ...
... of RFH fluid is similar to the discharge of the global river system into the ocean; thus a volume equivalent to that of the global ocean is passed through the crust about once every 105 –106 years (e.g., Mottl and Wheat, 1994; Johnson and Pruis, 2003; Wheat et al., 2003). This is a very short residen ...
Moho Depth and Crustal Velocity Structure Beneath Stations RTC
... Parfait N. ELOUMALA ONANA ; Aomar IBEN BRAHIM; Azelarab EL MOURA+OUAH; John R. EVANS. ...
... Parfait N. ELOUMALA ONANA ; Aomar IBEN BRAHIM; Azelarab EL MOURA+OUAH; John R. EVANS. ...
Chapter 5. The Eclogite Engine
... Bermuda, Jan Mayen, Rio Grande rise and Walvis ridge may be examples; the isotopic signatures of these plateaus are expected to reflect lower crustal components. ...
... Bermuda, Jan Mayen, Rio Grande rise and Walvis ridge may be examples; the isotopic signatures of these plateaus are expected to reflect lower crustal components. ...
117. Lee, C. - Cin
... arth is the only known planet in the solar system with continents and ocean basins. The continents ride high, about four kilometres above the seafloor. They are composed of thick, silicic crust that is more buoyant than the thin, dense crust that floors the oceans. Oceanic crust is thin — only about ...
... arth is the only known planet in the solar system with continents and ocean basins. The continents ride high, about four kilometres above the seafloor. They are composed of thick, silicic crust that is more buoyant than the thin, dense crust that floors the oceans. Oceanic crust is thin — only about ...
exploring the deep
... vents might occur in undersea volcanic areas, but this was the first time anyone had seen one. So what gave scientists the idea that thermal vents existed? Scientists thought that as the new seafloor formed at the ridges, rocks would split. This would allow seawater to seep into the hotter parts of ...
... vents might occur in undersea volcanic areas, but this was the first time anyone had seen one. So what gave scientists the idea that thermal vents existed? Scientists thought that as the new seafloor formed at the ridges, rocks would split. This would allow seawater to seep into the hotter parts of ...
Preview Sample 2
... This mantle-like mass cooled and hardened, resulting in our Moon. 8. Why is the Earth round? Self-gravity forces objects the size of Earth to be nearly spherical (the most compact shape, minimizing the distances of points from the center). 9. What is the Earth’s magnetic field? Draw a representation ...
... This mantle-like mass cooled and hardened, resulting in our Moon. 8. Why is the Earth round? Self-gravity forces objects the size of Earth to be nearly spherical (the most compact shape, minimizing the distances of points from the center). 9. What is the Earth’s magnetic field? Draw a representation ...
Thermal Structure and Metamorphic Evolution of Subducting Slabs
... In the subducting mantle, olivine transforms to spinel at depths of 350 to 670 km and then to perovskite + magnesiowustite at 670 km depth [e.g., Kirby et al., 1996a]. These solidsolid reactions increase the density of the subducting slab. A number of studies [e.g., Green and Burnley, 1989; Kirby e ...
... In the subducting mantle, olivine transforms to spinel at depths of 350 to 670 km and then to perovskite + magnesiowustite at 670 km depth [e.g., Kirby et al., 1996a]. These solidsolid reactions increase the density of the subducting slab. A number of studies [e.g., Green and Burnley, 1989; Kirby e ...
Poster introductions, viewing and reception
... The seabed substrate layer is provided by EMODnet Geology. The biological zone and oxygen regime layers are produced by overlaying oceanography data layers that are compiled from fundamental physical parameters in the basin (i.e. bathymetry, light, temperature, and density). The entire workflow is c ...
... The seabed substrate layer is provided by EMODnet Geology. The biological zone and oxygen regime layers are produced by overlaying oceanography data layers that are compiled from fundamental physical parameters in the basin (i.e. bathymetry, light, temperature, and density). The entire workflow is c ...
Chapter 13 Exploring the Oceans
... to break apart. The North Atlantic Ocean and the Indian Ocean began to form. ...
... to break apart. The North Atlantic Ocean and the Indian Ocean began to form. ...
Alteration of the subducting oceanic lithosphere at the southern
... [1] Hydrothermal circulation and brittle faulting processes affecting the oceanic lithosphere are usually confined to the upper crust for oceanic lithosphere created at intermediate to fast spreading rates. Lower crust and mantle rocks are therefore relatively dry and undeformed. However, recent stu ...
... [1] Hydrothermal circulation and brittle faulting processes affecting the oceanic lithosphere are usually confined to the upper crust for oceanic lithosphere created at intermediate to fast spreading rates. Lower crust and mantle rocks are therefore relatively dry and undeformed. However, recent stu ...
Strategic Plan - Ocean Networks Canada
... Internet connectivity to a broad suite of subsea instruments from coastal to deep-ocean environments. ONC also supports sensors installed on ferries, gliders and moorings, coastal radar, and community-based observatories located in remote locations (e.g. the Arctic, along the British Columbia coast, ...
... Internet connectivity to a broad suite of subsea instruments from coastal to deep-ocean environments. ONC also supports sensors installed on ferries, gliders and moorings, coastal radar, and community-based observatories located in remote locations (e.g. the Arctic, along the British Columbia coast, ...
The Deadliest Tsunami in History
... (Read "Tsunami: Facts About Killer Waves" for more about killer waves' causes and warning signs—information that can be a lifesaver in a tsunami zone.) The Indian Ocean tsunami traveled as much as 3,000 miles (nearly 5,000 kilometers) to Africa, arriving with sufficient force to kill people and dest ...
... (Read "Tsunami: Facts About Killer Waves" for more about killer waves' causes and warning signs—information that can be a lifesaver in a tsunami zone.) The Indian Ocean tsunami traveled as much as 3,000 miles (nearly 5,000 kilometers) to Africa, arriving with sufficient force to kill people and dest ...
Document
... Can we relate this material directly to new production as the biological pump concept requires (e.g. Michaels and Silver 1988), since mesoplankton fecal pellets will usually not represent more than a small fraction of the total consumption in the overlying photic zone? The concept that sinking fecal ...
... Can we relate this material directly to new production as the biological pump concept requires (e.g. Michaels and Silver 1988), since mesoplankton fecal pellets will usually not represent more than a small fraction of the total consumption in the overlying photic zone? The concept that sinking fecal ...
Chapter 12 Foundations of Life in the Oceans
... ●● methane to carbon dioxide and water. Note that “oxidation” does not necessarily require oxygen atoms to be present. Oxidation is the general term for a chemical reaction in which an electron is removed from a molecule that is being oxidized so certain molecules or atoms that do not contain oxygen ...
... ●● methane to carbon dioxide and water. Note that “oxidation” does not necessarily require oxygen atoms to be present. Oxidation is the general term for a chemical reaction in which an electron is removed from a molecule that is being oxidized so certain molecules or atoms that do not contain oxygen ...
ch07_crct plate tectonics
... 1. How do mid-ocean ridges support both the idea of continental drift and the theory of plate tectonics? A Oceanic lithosphere is destroyed at mid-ocean ridges. B New crust forms at mid-ocean ridges. C Tectonic plates collide at mid-ocean ridges. D The crust at mid-ocean ridges is old oceanic ...
... 1. How do mid-ocean ridges support both the idea of continental drift and the theory of plate tectonics? A Oceanic lithosphere is destroyed at mid-ocean ridges. B New crust forms at mid-ocean ridges. C Tectonic plates collide at mid-ocean ridges. D The crust at mid-ocean ridges is old oceanic ...
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.