Water transportation from the subducting slab into the mantle
... and King, 1992; Furukawa, 1993a,b; Peacock et al., 1994). Moreover, although poorly known, (7) the role of fluid dehydrated from the downgoing slab (Anderson et al., 1976, 1978; Delany and Helgeson, 1978), and (8) the exothermic or endothermic reaction within it would affect the thermal structure of ...
... and King, 1992; Furukawa, 1993a,b; Peacock et al., 1994). Moreover, although poorly known, (7) the role of fluid dehydrated from the downgoing slab (Anderson et al., 1976, 1978; Delany and Helgeson, 1978), and (8) the exothermic or endothermic reaction within it would affect the thermal structure of ...
Mobility and immobility of mid-ocean ridges and their implications to
... The observations that the SWIR may be tapping the same portion of the mantle as did the CIR, and the correlation between absolute migration velocity and the depth of origin of mid-ocean ridges has far-reaching thermal and chemical implications. One of the most important dynamic processes in the eart ...
... The observations that the SWIR may be tapping the same portion of the mantle as did the CIR, and the correlation between absolute migration velocity and the depth of origin of mid-ocean ridges has far-reaching thermal and chemical implications. One of the most important dynamic processes in the eart ...
Chapter 13 - The Theory of Plate Tectonics
... the Atlantic Ocean and Indian Ocean will expand the Pacific Ocean will shrink Australia will continue to drift toward Eurasia. ...
... the Atlantic Ocean and Indian Ocean will expand the Pacific Ocean will shrink Australia will continue to drift toward Eurasia. ...
Benthic Foraminiferal Biogeography: Controls on Global Distribution
... have described most of the known species. Estimates of the number of extant species range from ∼4,100 (Murray 2007) to 10,000–12,000 (Boltovskoy & Wright 1976). Many of the described benthic species have robust shells (“tests”) composed of calcareous material and fossilize readily. Others have agglu ...
... have described most of the known species. Estimates of the number of extant species range from ∼4,100 (Murray 2007) to 10,000–12,000 (Boltovskoy & Wright 1976). Many of the described benthic species have robust shells (“tests”) composed of calcareous material and fossilize readily. Others have agglu ...
Foraminiferal assemblages on the Antarctic shelf are often
... studies. A species living on scallop shells in Explorers Cove (McMurdo Sound) and previously identified as C. refulgens was reassigned to C. antarcticus (Saidova 1975) by Schweitzer et al. (in press). SSU rDNA sequences (in Schweitzer et al., 2009) revealed that this species forms a well-supported c ...
... studies. A species living on scallop shells in Explorers Cove (McMurdo Sound) and previously identified as C. refulgens was reassigned to C. antarcticus (Saidova 1975) by Schweitzer et al. (in press). SSU rDNA sequences (in Schweitzer et al., 2009) revealed that this species forms a well-supported c ...
Deep-Sea Life
... This book describes how manmade litter, primarily plastic, has spread into the remotest parts of the oceans and covers all aspects of this pollution problem from the impacts on wildlife and human health to socio-economic and political issues. Marine litter is a prime threat to marine wildlife, habit ...
... This book describes how manmade litter, primarily plastic, has spread into the remotest parts of the oceans and covers all aspects of this pollution problem from the impacts on wildlife and human health to socio-economic and political issues. Marine litter is a prime threat to marine wildlife, habit ...
Voyager
... never walk out onto the exposed seafloor after the water has receded because another tsunami wave will arrive within minutes. At the time of the 2004 Indian Ocean tsunami, a vacationing 10-year-old British girl saw water rapidly being pulled out to sea and recognized this as the sign of an impending ...
... never walk out onto the exposed seafloor after the water has receded because another tsunami wave will arrive within minutes. At the time of the 2004 Indian Ocean tsunami, a vacationing 10-year-old British girl saw water rapidly being pulled out to sea and recognized this as the sign of an impending ...
Homework Assignment #2: Plate Tectonics and
... Study Figure 7.8 on p. 200–201. Note the following aspects of this diagram: (a) Each plate is shown in a different color. The darker shade of each color is dry land--the continents. (b) This map shows topography as “shaded-relief.” The flat shallow parts of the oceans around the edges of the contine ...
... Study Figure 7.8 on p. 200–201. Note the following aspects of this diagram: (a) Each plate is shown in a different color. The darker shade of each color is dry land--the continents. (b) This map shows topography as “shaded-relief.” The flat shallow parts of the oceans around the edges of the contine ...
Earth Planet. Sci. Lett., 139, 1-16, 1996.
... sedimentary aprons. This hypothesis is critically dependent upon the quality of the bathymetric data acquired over the young seafloor just east of the hot-spot tracks (Fig. 1); first, because the observation of anomalously shallow depths in this area is largely responsible for the long-wavelength (p ...
... sedimentary aprons. This hypothesis is critically dependent upon the quality of the bathymetric data acquired over the young seafloor just east of the hot-spot tracks (Fig. 1); first, because the observation of anomalously shallow depths in this area is largely responsible for the long-wavelength (p ...
Using Isotopes to Understand the Oceans and Climate Change
... Oceans. Surface ocean pH has declined by 0.1 unit since the onset of the industrial revolution; most of that change occurring over the last 30 years. By the end of this century, surface ocean pH will drop by another 0.3 to 0.4 units, which represents a 100 to 150% increase in hydrogen ion concentrat ...
... Oceans. Surface ocean pH has declined by 0.1 unit since the onset of the industrial revolution; most of that change occurring over the last 30 years. By the end of this century, surface ocean pH will drop by another 0.3 to 0.4 units, which represents a 100 to 150% increase in hydrogen ion concentrat ...
PPT - Margins
... of mantle melt (Lizzaradle et al., 2007): earlier transition to narrow rift mode • Reduction of differences in buoyancy forces (Bialas and Buck, 2007; submitted): earlier transition to narrow rift mode • Diffuse deformation, after transition to narrow rift mode (Persaud et al., 2003) • Build new tra ...
... of mantle melt (Lizzaradle et al., 2007): earlier transition to narrow rift mode • Reduction of differences in buoyancy forces (Bialas and Buck, 2007; submitted): earlier transition to narrow rift mode • Diffuse deformation, after transition to narrow rift mode (Persaud et al., 2003) • Build new tra ...
Notes and Discussions RICHARD H. SILLITOE Institute de
... sequence from west to east: Fe; Cu (with some Au and Mo); Pb, Zn, and Ag; and in some regions Sn or Mo. The genesis of these metal provinces is attributed to the release of metals or associations of metals from basaltic oceanic crust and pelagic sediments during partial melting at progressively deep ...
... sequence from west to east: Fe; Cu (with some Au and Mo); Pb, Zn, and Ag; and in some regions Sn or Mo. The genesis of these metal provinces is attributed to the release of metals or associations of metals from basaltic oceanic crust and pelagic sediments during partial melting at progressively deep ...
PLATE TECTONICS: Lecture 5
... depends on the fact that refractory lithosphere (which has lost its basalt component at mid-ocean ridges) is less dense and inherently more buoyant than normal fertile mantle. Thus it would rise if heated to same temperature as surrounding mantle. Such diapirs could in theory be derived from subduct ...
... depends on the fact that refractory lithosphere (which has lost its basalt component at mid-ocean ridges) is less dense and inherently more buoyant than normal fertile mantle. Thus it would rise if heated to same temperature as surrounding mantle. Such diapirs could in theory be derived from subduct ...
MODULE #1: The Oceans of Our Planet Introduction This course is
... Mid-ocean ridge – A continuous chain of underwater volcanic mountains which encompass the earth Some mountains of the various mid-ocean ridges rise so high that they actually extend above the ocean’s surface and form islands, such as the Azores in the Atlantic Ocean. The ridges seem to snake along t ...
... Mid-ocean ridge – A continuous chain of underwater volcanic mountains which encompass the earth Some mountains of the various mid-ocean ridges rise so high that they actually extend above the ocean’s surface and form islands, such as the Azores in the Atlantic Ocean. The ridges seem to snake along t ...
Magma Emplacement Room Problem How to Accommodate Plutons
... • Pluton contact is subparallel and concordant with foliation in the country rock. • Magmatic minerals have the same isotopic age as minerals that define the age of foliation in the country rock ...
... • Pluton contact is subparallel and concordant with foliation in the country rock. • Magmatic minerals have the same isotopic age as minerals that define the age of foliation in the country rock ...
Study of frontal zones in the crozet-kerguelen region
... Subtropical Convergences are effectively located bet- ' ween 46 and 43°S. Along this meridian, it is difftcult to individualize a subantarctic region which would be characterized, between 200 and 600 m, by a relatively homogeneous water mass with an average temperature of about 9°C and an average sa ...
... Subtropical Convergences are effectively located bet- ' ween 46 and 43°S. Along this meridian, it is difftcult to individualize a subantarctic region which would be characterized, between 200 and 600 m, by a relatively homogeneous water mass with an average temperature of about 9°C and an average sa ...
Key Question: 3
... 33. Oceans become deeper moving away from ridges due to: a. decreasing thickness of the lithosphere. b. increasing density of oceanic basalts. c. increases in sediment accumulations. d. polar wandering. e. thermal contraction of hot asthenosphere. Answer: E Key Question: 3 Skill: comprehension Diffi ...
... 33. Oceans become deeper moving away from ridges due to: a. decreasing thickness of the lithosphere. b. increasing density of oceanic basalts. c. increases in sediment accumulations. d. polar wandering. e. thermal contraction of hot asthenosphere. Answer: E Key Question: 3 Skill: comprehension Diffi ...
Could Iceland be a modern analogue for the Earth`s early
... interpreted in terms of both degree of differentiation and source composition. Martin and Sigmarsson (2007b) showed that in basalt flows, the composition (i.e. K2O ⁄ Na2O) of felsic melts in segregation veins is mainly controlled by the composition of the parental magma. In mantle plume environments, ...
... interpreted in terms of both degree of differentiation and source composition. Martin and Sigmarsson (2007b) showed that in basalt flows, the composition (i.e. K2O ⁄ Na2O) of felsic melts in segregation veins is mainly controlled by the composition of the parental magma. In mantle plume environments, ...
Research Article
... oxic/anoxic interface meets the sea floor. On the Inebolu transect the steep decline in number of taxonomic groups occurred between 130 m and 150 m depth, already in the suboxic zone. Mobile forms with high oxygen demands such as crustaceans or fish were restricted to this zone. Pioneer studies of d ...
... oxic/anoxic interface meets the sea floor. On the Inebolu transect the steep decline in number of taxonomic groups occurred between 130 m and 150 m depth, already in the suboxic zone. Mobile forms with high oxygen demands such as crustaceans or fish were restricted to this zone. Pioneer studies of d ...
Initiation of Subduction Zones as a Consequence
... respect to the asthenosphere. Therefore, it would be physically optimal if one part of the lithosphere experienced a greater gravitational attraction than its adjacent neighbour before or during the initiation of a subduction zone. This requires the pre-existence of a density contrast within the lit ...
... respect to the asthenosphere. Therefore, it would be physically optimal if one part of the lithosphere experienced a greater gravitational attraction than its adjacent neighbour before or during the initiation of a subduction zone. This requires the pre-existence of a density contrast within the lit ...
BasinWide Oceanographic Array Bridges the South Atlantic
... rings (green circles) and their saline influence into the eastern South Atlantic (green arcs) are shown. The existing South Atlantic MOC Basin-wide Array (SAMBA) array along 34.5°S is shown as a solid red line, and the proposed full transect, to be completed in 2014 and 2015, is shown as a dashed li ...
... rings (green circles) and their saline influence into the eastern South Atlantic (green arcs) are shown. The existing South Atlantic MOC Basin-wide Array (SAMBA) array along 34.5°S is shown as a solid red line, and the proposed full transect, to be completed in 2014 and 2015, is shown as a dashed li ...
a 22 page PDF of this title
... areas of Earth with different density and elastic properties from those seen at the surface. This reasoning showed that Earth is not homogeneous and that its properties vary ...
... areas of Earth with different density and elastic properties from those seen at the surface. This reasoning showed that Earth is not homogeneous and that its properties vary ...
Chapter 1 Introduction – Planet, Oceans and Life
... The new map shows the way in which the ocean consists of four main basins (the Arctic Ocean, the Atlantic Ocean, the Indian Ocean and the Pacific Ocean) between the tectonic plates that form the continents. The tectonic plates have differing forms at their edges, giving broad or narrow continental s ...
... The new map shows the way in which the ocean consists of four main basins (the Arctic Ocean, the Atlantic Ocean, the Indian Ocean and the Pacific Ocean) between the tectonic plates that form the continents. The tectonic plates have differing forms at their edges, giving broad or narrow continental s ...
Ocean Boundary Currents - Student Climate Data
... Western boundary currents are among the largest and strongest ocean currents and typically move 40 to 120 km (25 and 75 miles) per day. These currents also extend much deeper than most other surface currents, down to a depth of 1000 m (3300 feet) or more. Thus, the strong western boundary currents a ...
... Western boundary currents are among the largest and strongest ocean currents and typically move 40 to 120 km (25 and 75 miles) per day. These currents also extend much deeper than most other surface currents, down to a depth of 1000 m (3300 feet) or more. Thus, the strong western boundary currents a ...
Chemistry of the Oceans
... OCEANOGRAPHY – Vol.I - Chemistry of the Oceans - Chen-Tung Arthur Chen ...
... OCEANOGRAPHY – Vol.I - Chemistry of the Oceans - Chen-Tung Arthur Chen ...
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.