Past and present natural methane seepage on the northern
... gas in the Earth's atmosphere (Lashof and Ahuja, 1990; Makogon et al., 2007). From an energy source point of view, it is estimated that actually 53% of all fossil fuel, including coal, oil and natural gas, is stored in the form of methane hydrate in the sub seabed and beneath arctic permafrost (Lee ...
... gas in the Earth's atmosphere (Lashof and Ahuja, 1990; Makogon et al., 2007). From an energy source point of view, it is estimated that actually 53% of all fossil fuel, including coal, oil and natural gas, is stored in the form of methane hydrate in the sub seabed and beneath arctic permafrost (Lee ...
Topography and geoid due to lithospheric mass anomalies
... conclude that no dynamic topography is observed (Colin & Fleitout 1990). Even if this flattening is due to deep-mantle effects, only some 500 m peak-to-peak topography can be associated with deep circulation effects (Cazenave & Lago 1991). Second, if large-scale dynamic topography were stationary wi ...
... conclude that no dynamic topography is observed (Colin & Fleitout 1990). Even if this flattening is due to deep-mantle effects, only some 500 m peak-to-peak topography can be associated with deep circulation effects (Cazenave & Lago 1991). Second, if large-scale dynamic topography were stationary wi ...
Chapter 5 Geochemical Weathering
... primary mineral phases and transport of solutes in groundwater. Primary phases include high temperature minerals formed by magmatic and metamorphic processes ― the aluminosilicate granites and gneisses that make up shield terrains of continental cratons, and ferromagnesian silicates like basalts tha ...
... primary mineral phases and transport of solutes in groundwater. Primary phases include high temperature minerals formed by magmatic and metamorphic processes ― the aluminosilicate granites and gneisses that make up shield terrains of continental cratons, and ferromagnesian silicates like basalts tha ...
Chapter 5. The Eclogite Engine
... tectonic or igneous processes , eventually forming dense eclogite that detaches and sinks into the mantle. It reaches a level of neutral buoyancy and starts to warm up. Eventually it rises and forms a warm fertile patch in the mantle. If the overlying continents have moved off, a midplate magmatic p ...
... tectonic or igneous processes , eventually forming dense eclogite that detaches and sinks into the mantle. It reaches a level of neutral buoyancy and starts to warm up. Eventually it rises and forms a warm fertile patch in the mantle. If the overlying continents have moved off, a midplate magmatic p ...
Evidence for plate tectonics, part 1
... The results of plate tectonic processes abound, from the mighty folds of the ancient and well worn Appalachians, the majestic escarpments of the East African Rift Valley and the Palisades of the Hudson River, and the volcanoes that imperil cities in Iceland, Indonesia, Japan and Mexico. Even idylli ...
... The results of plate tectonic processes abound, from the mighty folds of the ancient and well worn Appalachians, the majestic escarpments of the East African Rift Valley and the Palisades of the Hudson River, and the volcanoes that imperil cities in Iceland, Indonesia, Japan and Mexico. Even idylli ...
Atlantic volcanic margins: a comparative study
... and structural features developed during continental extension and break-up. We suggest that four main crustal zones can be recognized on volcanic margins. This tectono-magmatic zonation implies a history of development where tectonic and magmatic styles and dimensions depend on the interaction of l ...
... and structural features developed during continental extension and break-up. We suggest that four main crustal zones can be recognized on volcanic margins. This tectono-magmatic zonation implies a history of development where tectonic and magmatic styles and dimensions depend on the interaction of l ...
current O a —
... Deep-sea corals). These ecosystems are bathed in waters that have naturally high levels of CO2; however, more than 95% of cold-water coral reefs occur in waters that are supersaturated with respect to aragonite. Future projections of ocean acidification, however, indicate that 70% of cold-water cora ...
... Deep-sea corals). These ecosystems are bathed in waters that have naturally high levels of CO2; however, more than 95% of cold-water coral reefs occur in waters that are supersaturated with respect to aragonite. Future projections of ocean acidification, however, indicate that 70% of cold-water cora ...
Present and Future Impacts of Ocean Acidification Report of the
... that will reduce potential negative impacts of ocean acidification? Ocean acidification-relevant indicators beyond basic water-column carbonate chemistry have yet to be adequately developed. Parameters that can be measured routinely and that detect biotic effects of ocean acidification reliably, su ...
... that will reduce potential negative impacts of ocean acidification? Ocean acidification-relevant indicators beyond basic water-column carbonate chemistry have yet to be adequately developed. Parameters that can be measured routinely and that detect biotic effects of ocean acidification reliably, su ...
Here are the study questions for the Exam 3. There are
... (a) seals and other smaller marine mammals. (b) fish, especially tuna. (c) plankton near the surface of the water. (d) benthic crabs. (e) none of these Answer: c [p. 309] 4. Which of the following statements best describes the global distribution of phytoplankton? (a) In the poles, phytoplankton pop ...
... (a) seals and other smaller marine mammals. (b) fish, especially tuna. (c) plankton near the surface of the water. (d) benthic crabs. (e) none of these Answer: c [p. 309] 4. Which of the following statements best describes the global distribution of phytoplankton? (a) In the poles, phytoplankton pop ...
Where and why do large shallow slab earthquakes occur?
... Earthquake Research Institute, University of Tokyo, Tokyo, Japan (submitted to J. Geophys. Res., on Jan. 18, 2001) Abstract. It has been believed that large earthquakes seldom occur within the shallow portion (20-60 km depth) of a subducting slab, because the differential stress there is generally e ...
... Earthquake Research Institute, University of Tokyo, Tokyo, Japan (submitted to J. Geophys. Res., on Jan. 18, 2001) Abstract. It has been believed that large earthquakes seldom occur within the shallow portion (20-60 km depth) of a subducting slab, because the differential stress there is generally e ...
Water transportation from the subducting slab into the mantle
... the structural water at about 2.7 wt.% and the interstitial water is at least 2 wt.%, based on the void volume of the crust (approximately 5 vol.% by Johnson, 1979). The present study uses 5–6 wt.% H2O+ which is stored in hydrous minerals due to ocean-floor hydrothermal metamorphism. Dredged gabbros ...
... the structural water at about 2.7 wt.% and the interstitial water is at least 2 wt.%, based on the void volume of the crust (approximately 5 vol.% by Johnson, 1979). The present study uses 5–6 wt.% H2O+ which is stored in hydrous minerals due to ocean-floor hydrothermal metamorphism. Dredged gabbros ...
Paleoceanographical proxies based on deep-sea
... living foraminifera has been seriously questioned, especially in anoxic environments where protoplasm decay may be very slow (e.g., Corliss & Emerson, 1990). Studies using more specific vital stains have confirmed that some foraminiferal species can indeed live, and be active, in anoxic sediments (B ...
... living foraminifera has been seriously questioned, especially in anoxic environments where protoplasm decay may be very slow (e.g., Corliss & Emerson, 1990). Studies using more specific vital stains have confirmed that some foraminiferal species can indeed live, and be active, in anoxic sediments (B ...
Plate tectonic reconstructions and - Archimer
... thinned continental crust, slightly extending to the northwest of the high velocity body. The ECMA may be also partly caused by the edge effect due to the juxtaposition of a ~6-km thick magnetized serpentinized body and the poorly magnetized thinned continental crust. East of 56.5°W, the disconnecte ...
... thinned continental crust, slightly extending to the northwest of the high velocity body. The ECMA may be also partly caused by the edge effect due to the juxtaposition of a ~6-km thick magnetized serpentinized body and the poorly magnetized thinned continental crust. East of 56.5°W, the disconnecte ...
Do faults trigger folding in the lithosphere
... i.e. lithospheric buckling or folding. These undulations are normally associated with intensive faulting, which raises questions on the role of faulting in the folding process, and even on the possibility of folding in highly faulted media. In this study, we demonstrate that folding can "survive" fa ...
... i.e. lithospheric buckling or folding. These undulations are normally associated with intensive faulting, which raises questions on the role of faulting in the folding process, and even on the possibility of folding in highly faulted media. In this study, we demonstrate that folding can "survive" fa ...
The Caribbean Ocean Plateau – an overview
... sites, showing the presence of a vast area (3,000 by 1,000 km) of shallow basaltic sills intruding sediment of about 88 Ma in age, probably formed as an oceanic flood basalt plateau (like Ontong Java). Cretaceous basalts in Panamá, Costa Rica, Guatemala, central Hispaniola, Jamaica, Belize, Trinidad ...
... sites, showing the presence of a vast area (3,000 by 1,000 km) of shallow basaltic sills intruding sediment of about 88 Ma in age, probably formed as an oceanic flood basalt plateau (like Ontong Java). Cretaceous basalts in Panamá, Costa Rica, Guatemala, central Hispaniola, Jamaica, Belize, Trinidad ...
New bathymetry and magnetic lineations identifications in the
... The seafloor spreading of the South China Sea (SCS) was previously believed to take place between ca. 32 and 15 Ma (magnetic anomaly C11 to C5c). New magnetic data acquired in the northernmost SCS however suggests the existence of E–W trending magnetic polarity reversal patterns. Magnetic modeling de ...
... The seafloor spreading of the South China Sea (SCS) was previously believed to take place between ca. 32 and 15 Ma (magnetic anomaly C11 to C5c). New magnetic data acquired in the northernmost SCS however suggests the existence of E–W trending magnetic polarity reversal patterns. Magnetic modeling de ...
Massive marine methane emissions from near
... Methane is the second most important greenhouse gas contributing to climate warming. The open ocean is a minor source of methane to the atmosphere. We report intense methane emissions from the near-shore southern region of the North Sea characterized by the presence of extensive areas with gassy sed ...
... Methane is the second most important greenhouse gas contributing to climate warming. The open ocean is a minor source of methane to the atmosphere. We report intense methane emissions from the near-shore southern region of the North Sea characterized by the presence of extensive areas with gassy sed ...
Deposition of the Early to Late Permian Whitehill Formation during a
... of the Ecca Group in the western half of the Karoo Basin (Figure 1). This white-weathering unit is persistent throughout the area which makes it an excellent marker horizon and, together with its characteristic fossil assemblage, a time-stratigraphic marker. It was furthermore considered as a potent ...
... of the Ecca Group in the western half of the Karoo Basin (Figure 1). This white-weathering unit is persistent throughout the area which makes it an excellent marker horizon and, together with its characteristic fossil assemblage, a time-stratigraphic marker. It was furthermore considered as a potent ...
Plate Tectonics - The Web site cannot be found
... Plate tectonics is an expression of the Earth’s long term loss of internal heat. In a first approximation the Earth comprises two different liquids, the core with a diameter of ca. 3200 km and the mantle with a thickness of ca. 2900 km which surrounds the core. Since the temperature outside the Eart ...
... Plate tectonics is an expression of the Earth’s long term loss of internal heat. In a first approximation the Earth comprises two different liquids, the core with a diameter of ca. 3200 km and the mantle with a thickness of ca. 2900 km which surrounds the core. Since the temperature outside the Eart ...
the fate of subducted oceanic crust and the origin
... Allègre 1982). A primitive lower mantle had also been suggested from the chondritic Nd-Sr isotope compositions measured in continental basalts (Wasserburg and DePaolo 1979), and a deep primitive reservoir was suggested by Allègre et al. (1983) as the source of apparent excess primordial 3He in Hawai ...
... Allègre 1982). A primitive lower mantle had also been suggested from the chondritic Nd-Sr isotope compositions measured in continental basalts (Wasserburg and DePaolo 1979), and a deep primitive reservoir was suggested by Allègre et al. (1983) as the source of apparent excess primordial 3He in Hawai ...
IMPLICATIONS OF PHYTOPLANKTON CELL DEATH LOSSES TESIS DOCTORAL Autor: Sébastien Lasternas
... Phytoplankton losses by cell death, independent of grazing are occurring in the ocean. Phytoplankton cells have been described to die upon encountering adverse environmental conditions, and cell death and lysis would result in the release of the carbon incorporated in the photosynthesis by the phyto ...
... Phytoplankton losses by cell death, independent of grazing are occurring in the ocean. Phytoplankton cells have been described to die upon encountering adverse environmental conditions, and cell death and lysis would result in the release of the carbon incorporated in the photosynthesis by the phyto ...
Anoxic event
Oceanic anoxic events or anoxic events (Anoxia conditions) refer to intervals in the Earth's past where portions of oceans become depleted in oxygen (O2) at depths over a large geographic area. During some of these events, euxinia develops - euxinia refers to anoxic waters that contain H2S hydrogen sulfide. Although anoxic events have not happened for millions of years, the geological record shows that they happened many times in the past. Anoxic events coincide with several mass extinctions and may contribute to these events. These mass extinctions include some that geobiologists use as time markers in biostratigraphic dating. It is believed oceanic anoxic events are strongly linked to slowing of ocean circulation, climatic warming and elevated levels of greenhouse gases. Enhanced volcanism (through the release of CO2 and other greenhouse gases) is the proposed central external trigger for the development of these events.