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Heceta Bank
Heceta Bank is a rocky bank located 55 kilometers (km) off the Oregon coast near Florence, centered on approximately 44°N, 125°W, and is roughly 29 km long and upwards of 13 km wide. Heceta Bank is an area of ecological and oceanographic importance. The unique bathymetric features and seasonal circulation within the bank provides habitat for a diversity of economically-important fish species. Heceta Bank also plays an important role in current understanding of prehistoric human migration. During the last glacial low stand, approximately 15,000–20,000 years ago, prehistoric humans migrated from northeastern Asia into North America. Scientists hypothesize that Heceta Bank, due to its topography and morphology, is a possible area of this historical migration. Geomorphology Formation Heceta Bank is one of four commonly-identified offshore rocky banks – including Nehalem, Stonewall, and Coquille – that break up the outer limits of the continental shelf off the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heceta Map
Heceta may refer to: *Bruno de Heceta, a Spanish explorer of the west coast of North America *Heceta Beach, Oregon, an unincorporated community in the United States *Heceta Head, a headland in Oregon, United States *Heceta Head Light Heceta Head Light is a lighthouse on the Oregon Coast north of Florence, and south of Yachats in the United States. It is located at Heceta Head Lighthouse State Scenic Viewpoint, a state park, midway up a 205-foot-tall (62 m) headland. Bui ..., a lighthouse on Heceta Head * Heceta Island, an island off the coast of Alaska, United States {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upwelling
Upwelling is an oceanographic phenomenon that involves wind-driven motion of dense, cooler, and usually nutrient-rich water from deep water towards the ocean surface. It replaces the warmer and usually nutrient-depleted surface water. The nutrient-rich upwelled water stimulates the growth and reproduction of primary producers such as phytoplankton. The biomass of phytoplankton and the presence of cool water in those regions allow upwelling zones to be identified by cool sea surface temperatures (SST) and high concentrations of chlorophyll-a. The increased availability of nutrients in upwelling regions results in high levels of primary production and thus fishery production. Approximately 25% of the total global marine fish catches come from five upwellings, which occupy only 5% of the total ocean area.Jennings, S., Kaiser, M.J., Reynolds, J.D. (2001) "Marine Fisheries Ecology." Oxford: Blackwell Science Ltd. Upwellings that are driven by coastal currents or diverging open oc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methanogenesis
Methanogenesis or biomethanation is the formation of methane coupled to energy conservation by microbes known as methanogens. Organisms capable of producing methane for energy conservation have been identified only from the domain Archaea, a group phylogenetically distinct from both eukaryotes and bacteria, although many live in close association with anaerobic bacteria. Other forms of methane production that are not coupled to ATP synthesis exist within all three domains of life. The production of methane is an important and widespread form of microbial metabolism. In anoxic environments, it is the final step in the decomposition of biomass. Methanogenesis is responsible for significant amounts of natural gas accumulations, the remainder being thermogenic. Biochemistry Methanogenesis in microbes is a form of anaerobic respiration. Methanogens do not use oxygen to respire; in fact, oxygen inhibits the growth of methanogens. The terminal electron acceptor in methanogenesis is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methane Clathrate
Methane clathrate (CH4·5.75H2O) or (8CH4·46H2O), also called methane hydrate, hydromethane, methane ice, fire ice, natural gas hydrate, or gas hydrate, is a solid clathrate compound (more specifically, a clathrate hydrate) in which a large amount of methane is trapped within a crystal structure of water, forming a solid similar to ice. Originally thought to occur only in the outer regions of the Solar System, where temperatures are low and water ice is common, significant deposits of methane clathrate have been found under sediments on the ocean floors of the Earth. Methane hydrate is formed when hydrogen-bonded water and methane gas come into contact at high pressures and low temperatures in oceans. Methane clathrates are common constituents of the shallow marine geosphere and they occur in deep Sedimentary rock, sedimentary structures and form outcrops on the ocean floor. Methane hydrates are believed to form by the precipitation or crystallisation of methane migrating from d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Expn0686 (14526221693)
ESPN Inc. is an American multinational sports media conglomerate majority-owned by The Walt Disney Company, with Hearst Communications as an equity stakeholder. For management and financial reporting purposes, the company is the main entity within the ESPN and Sports Content segment of Disney. Headed by James Pitaro, it owns and operates local and global cable and satellite television variants of ESPN, ESPN Radio, ESPN.com and other related ventures. Commonly and colloquially marketed as the "Worldwide Leader in Sports", programming on its television networks include broadcasts of live or tape-delayed sporting events and sports-related programming including talk shows and original documentary series and films. History ESPN Inc. was founded in 1979 by Bill Rasmussen, initially as an attempt to broadcast Connecticut sports over an "Entertainment and Sports Programming Network" (ESPN) cable channel, and soon became a nationwide cable sports network. Shortly after being termin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
