article 76: the ridge issue
... by researchers to characterise and classify the seafloor in their studies of how oceans evolve. One or more of these may be useful to help us derive an acceptable FOS position. Magnetic anomalies, gravity anomalies and a selected isobath are probably the most readily available, easily and relatively ...
... by researchers to characterise and classify the seafloor in their studies of how oceans evolve. One or more of these may be useful to help us derive an acceptable FOS position. Magnetic anomalies, gravity anomalies and a selected isobath are probably the most readily available, easily and relatively ...
Power Point Presentation
... Plate Tectonics - evidence for theory of continental drift by Hess, Heezen and Tharp (1960’s) found lithospheres plate boundaries that can be 3 types: 1) ridges (spreading centers) 2) trenches (subduction zones) 3) transform faults (plates sliding past one another) ...
... Plate Tectonics - evidence for theory of continental drift by Hess, Heezen and Tharp (1960’s) found lithospheres plate boundaries that can be 3 types: 1) ridges (spreading centers) 2) trenches (subduction zones) 3) transform faults (plates sliding past one another) ...
D o e I
... developed at WHOI to monitor deformation in Kilauea’s submarine flank. Extensometers measure small increments of deformation. When many are used in a network, a continuous time series can be obtained, showing incremental changes in land formation. The continuous time series obtained by the extensome ...
... developed at WHOI to monitor deformation in Kilauea’s submarine flank. Extensometers measure small increments of deformation. When many are used in a network, a continuous time series can be obtained, showing incremental changes in land formation. The continuous time series obtained by the extensome ...
Mantle Processes
... One way that mantle peridotites may melt is by plastic flow of large regions toward the surface (i.e., lower pressures). ...
... One way that mantle peridotites may melt is by plastic flow of large regions toward the surface (i.e., lower pressures). ...
Regional anomalies of sediment thickness, basement depth and
... decompression melting. Widths of volcanic features indicate that thickening primarily occurs within 100 – 200 km of hotspots except along continental margins that rifted at the time of the hotspot activity (i.e. East Greenland and the HattonRockall Bank). We observe conjugate structures south of Gre ...
... decompression melting. Widths of volcanic features indicate that thickening primarily occurs within 100 – 200 km of hotspots except along continental margins that rifted at the time of the hotspot activity (i.e. East Greenland and the HattonRockall Bank). We observe conjugate structures south of Gre ...
Lecture_Ch03 - earthjay science
... explain “continental drift.” • Hess recognized a mechanism to explain continents being separated via spreading in one part of ocean crust and a sinking in another part (at trenches). • At mid-ocean ridges (MORs), new oceanic crust forms as lithosphere pulls apart and magma from mantle wells up, cool ...
... explain “continental drift.” • Hess recognized a mechanism to explain continents being separated via spreading in one part of ocean crust and a sinking in another part (at trenches). • At mid-ocean ridges (MORs), new oceanic crust forms as lithosphere pulls apart and magma from mantle wells up, cool ...
16_3eIG
... 3. Most of the seafloor is flat, but there are volcanic peaks, reefs, and deep trenches. 4. Oceanic zones differ greatly, and some support more life than others. a. The well-lit top 10 meters, called the photic zone, contains nearly all of the oceans’ primary productivity. b. Between the ocean’s sur ...
... 3. Most of the seafloor is flat, but there are volcanic peaks, reefs, and deep trenches. 4. Oceanic zones differ greatly, and some support more life than others. a. The well-lit top 10 meters, called the photic zone, contains nearly all of the oceans’ primary productivity. b. Between the ocean’s sur ...
Direct geological evidence for oceanic detachment faulting: The Mid
... Keywords: detachment fault, oceanic core complex, mid-ocean ridge, Mid-Atlantic Ridge. BACKGROUND Exposure of serpentinized peridotites on the seafloor at slow-spreading ridges implies that incorporation of asthenospheric mantle into the lithosphere must occur at the ridge axis. This observation req ...
... Keywords: detachment fault, oceanic core complex, mid-ocean ridge, Mid-Atlantic Ridge. BACKGROUND Exposure of serpentinized peridotites on the seafloor at slow-spreading ridges implies that incorporation of asthenospheric mantle into the lithosphere must occur at the ridge axis. This observation req ...
Temperature Differences in the Ocean at Low Latitude
... hand this energy returns back to the ocean in the form of wave energy and energy of streams. As far as specific thermal capacity of water exceeds about four times that of air, and the mass of water is 270 times more, the thermal energy accumulated in water is much more than in air. Solar radiation a ...
... hand this energy returns back to the ocean in the form of wave energy and energy of streams. As far as specific thermal capacity of water exceeds about four times that of air, and the mass of water is 270 times more, the thermal energy accumulated in water is much more than in air. Solar radiation a ...
Magnetic Evidence for Seafloor Spreading
... Away from the ridge crest, sediment becomes older and thicker, and the seafloor becomes thicker. Heat flow, which indicates the warmth of a region, is highest at the ridge crest. A map of sediment thickness is found here: http://earthguide.ucsd.edu/eoc/teachers/t_tectonics/p_sedimentthickn ess.html ...
... Away from the ridge crest, sediment becomes older and thicker, and the seafloor becomes thicker. Heat flow, which indicates the warmth of a region, is highest at the ridge crest. A map of sediment thickness is found here: http://earthguide.ucsd.edu/eoc/teachers/t_tectonics/p_sedimentthickn ess.html ...
Copyright (©) 2008, Elsevier Inc. All rights reserved. Chapter
... replaced by different currents associated with lower waves at another season. These currents are influenced by seasonal and interannual wind variations. In addition to their effects on sand transport it is important to have knowledge of these near-shore currents particularly in areas where people ar ...
... replaced by different currents associated with lower waves at another season. These currents are influenced by seasonal and interannual wind variations. In addition to their effects on sand transport it is important to have knowledge of these near-shore currents particularly in areas where people ar ...
Earth Science Chapter 9 Section 5 Review
... a. small amounts of material from the lower mantle move upward to the surface b. slabs of cold oceanic lithosphere move down and into the lower mantle c. large chunks of continental crust are pulled down into the lower mantle d. material from the inner core rises into the mantle to form super hot pl ...
... a. small amounts of material from the lower mantle move upward to the surface b. slabs of cold oceanic lithosphere move down and into the lower mantle c. large chunks of continental crust are pulled down into the lower mantle d. material from the inner core rises into the mantle to form super hot pl ...
Reader Chapter 2 In chapter 2 and 3 you can read more about the
... Archipelagic apron – a gentle slope with a smooth surface on the seafloor Bank – an elevation of the seafloor located on a shelf Basin – a depression of variable extent, generally in a circular or oval form Borderland – a region adjacent to a continent that is highly irregular with depths in excess ...
... Archipelagic apron – a gentle slope with a smooth surface on the seafloor Bank – an elevation of the seafloor located on a shelf Basin – a depression of variable extent, generally in a circular or oval form Borderland – a region adjacent to a continent that is highly irregular with depths in excess ...
To change the ocean water density we can: provide heating/cooling
... etc.), which impact on the zonal heat balance and propagate quickly to MHT through the integration: MHT, being physically a very important parameter, remains not very effective measure of the reliability of surface flux fields from a methodological viewpoint. Uncertainty of 10 W/m2 for the Atlantic ...
... etc.), which impact on the zonal heat balance and propagate quickly to MHT through the integration: MHT, being physically a very important parameter, remains not very effective measure of the reliability of surface flux fields from a methodological viewpoint. Uncertainty of 10 W/m2 for the Atlantic ...
Isostasy and Rock Density
... outer, rigid portion of the earth's surface, the lithosphere, is actually composed of a number of plates that ‘float’ on denser, more plastic material beneath, the asthenosphere, which is often called the mantle. When objects of different density float on a more dense, non-rigid material, the depth ...
... outer, rigid portion of the earth's surface, the lithosphere, is actually composed of a number of plates that ‘float’ on denser, more plastic material beneath, the asthenosphere, which is often called the mantle. When objects of different density float on a more dense, non-rigid material, the depth ...
Oceanic ridges - HCC Learning Web
... produces a continuous mountain range when the continents are positioned next to each other, as they were during the formation of Pangea. ...
... produces a continuous mountain range when the continents are positioned next to each other, as they were during the formation of Pangea. ...
between Earth Expansion and Seafloor Spreading
... basaltic magmatism (basification), and sub-crustal delamination, in a progressive manner that is similar to seafloor spreading in its horizontal propagation, but also quite different because there is no crustal displacement. In contrast, an expansion model based on King (1983) envisions that new oce ...
... basaltic magmatism (basification), and sub-crustal delamination, in a progressive manner that is similar to seafloor spreading in its horizontal propagation, but also quite different because there is no crustal displacement. In contrast, an expansion model based on King (1983) envisions that new oce ...
Processes that Shape the Surface of Earth
... The mantle also provides new igneous rocks to the continents away from subduction zones. New crust is created at hot spots, which are quasi-stationary or slow-moving thermal plumes rising through the mantle. These localized sources of high-heat energy partially melt the overlying continental plate, ...
... The mantle also provides new igneous rocks to the continents away from subduction zones. New crust is created at hot spots, which are quasi-stationary or slow-moving thermal plumes rising through the mantle. These localized sources of high-heat energy partially melt the overlying continental plate, ...
Plate Tectonics: A Unifying Theory
... produces a continuous mountain range when the continents are positioned next to each other, as they were during the formation of Pangea. ...
... produces a continuous mountain range when the continents are positioned next to each other, as they were during the formation of Pangea. ...
Mass balance related to UHP metamorphism in subduction zones
... The H2O recycling rate through subduction volcanoes (75-65 %) has to be complemented by ridge and plume volcanism, the higher recycling rate leads to reasonable concentrations in MORB (0.27 wt% H2O, compare to 0.2-0.4 wt% from geochemistry) and plume basalts (1.1% H2O, compare to 0.6-1.0 wt% from ge ...
... The H2O recycling rate through subduction volcanoes (75-65 %) has to be complemented by ridge and plume volcanism, the higher recycling rate leads to reasonable concentrations in MORB (0.27 wt% H2O, compare to 0.2-0.4 wt% from geochemistry) and plume basalts (1.1% H2O, compare to 0.6-1.0 wt% from ge ...
Student Worksheets, Assessments, and Answer Keys
... Later plate tectonics became the accepted reason for breakup of Pangea ...
... Later plate tectonics became the accepted reason for breakup of Pangea ...
Introduction to Petrology
... lighter elements). Heat from radioactive decay remelted some material from the mantle (and/or lower crust) which rose to the surface in the form of volcanic eruptions that formed the oceanic crust. Accordingly, during its early stages of evolution, and possibly up until the end of the Precambrian er ...
... lighter elements). Heat from radioactive decay remelted some material from the mantle (and/or lower crust) which rose to the surface in the form of volcanic eruptions that formed the oceanic crust. Accordingly, during its early stages of evolution, and possibly up until the end of the Precambrian er ...
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.