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Astoria Canyon
Astoria Canyon is a submarine canyon 10 miles (16 km) offshore from the mouth of the Columbia River. See also * Astoria Fan The Astoria Fan is a submarine fan. It has sediment, radiating asymmetrically southward from the mouth of the Astoria Canyon. From Astoria Canyon's mouth, the fan extends about to its western end, which is the Cascadia Channel. The fan proper en ... External links * https://web.archive.org/web/20050902223250/http://newport.pmel.noaa.gov/heceta/oceanexploration.htm Geography of the Pacific Northwest Submarine canyons of the Pacific Ocean {{marine-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astoria Canyon
Astoria Canyon is a submarine canyon 10 miles (16 km) offshore from the mouth of the Columbia River. See also * Astoria Fan The Astoria Fan is a submarine fan. It has sediment, radiating asymmetrically southward from the mouth of the Astoria Canyon. From Astoria Canyon's mouth, the fan extends about to its western end, which is the Cascadia Channel. The fan proper en ... External links * https://web.archive.org/web/20050902223250/http://newport.pmel.noaa.gov/heceta/oceanexploration.htm Geography of the Pacific Northwest Submarine canyons of the Pacific Ocean {{marine-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Submarine Canyon
A submarine canyon is a steep-sided valley cut into the seabed of the continental slope, sometimes extending well onto the continental shelf, having nearly vertical walls, and occasionally having canyon wall heights of up to 5 km, from canyon floor to canyon rim, as with the Great Bahama Canyon. Just as above-sea-level canyons serve as channels for the flow of water across land, submarine canyons serve as channels for the flow of turbidity currents across the seafloor. Turbidity currents are flows of dense, sediment laden waters that are supplied by rivers, or generated on the seabed by storms, submarine landslides, earthquakes, and other soil disturbances. Turbidity currents travel down slope at great speed (as much as 70 km/h), eroding the continental slope and finally depositing sediment onto the abyssal plain, where the particles settle out.Continental Margin Sedimentation: From Sediment Transport to Sequence Stratigraphy (Special Publication 37 of the IAS) Ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Columbia River
The Columbia River (Upper Chinook: ' or '; Sahaptin: ''Nch’i-Wàna'' or ''Nchi wana''; Sinixt dialect'' '') is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia, Canada. It flows northwest and then south into the U.S. state of Washington, then turns west to form most of the border between Washington and the state of Oregon before emptying into the Pacific Ocean. The river is long, and its largest tributary is the Snake River. Its drainage basin is roughly the size of France and extends into seven US states and a Canadian province. The fourth-largest river in the United States by volume, the Columbia has the greatest flow of any North American river entering the Pacific. The Columbia has the 36th greatest discharge of any river in the world. The Columbia and its tributaries have been central to the region's culture and economy for thousands of years. They have been used for transportation since a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astoria Fan
The Astoria Fan is a submarine fan. It has sediment, radiating asymmetrically southward from the mouth of the Astoria Canyon. From Astoria Canyon's mouth, the fan extends about to its western end, which is the Cascadia Channel. The fan proper ends south of the canyon mouth, although its depositional basin extends southward another to the Blanco Fracture Zone. Astoria Fan is generally asymmetrical. It extends roughly west of the mouth of Astoria Canyon, and about north, to Willapa Channel. Others trace different dimensions. Headed west, the fan crosses the continental shelf, trending sinuously down to the base of the continental slope. Near Astoria Canyon, it is at a depth of . The fan is approximately long. It varies in width from to . It has numerous tributaries. The fan extends about to its western boundary, which is the Cascadia Channel. Ash from the eruption of Mount Mazama has been found, in Astoria Fan. It may have been cut in the Pleistocene. It appears the Mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geography Of The Pacific Northwest
The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Though no official boundary exists, the most common conception includes the U.S. states of Oregon, Washington, and Idaho, and the Canadian province of British Columbia. Some broader conceptions reach north into Alaska and Yukon, south into northern California, and east into western Montana. Other conceptions may be limited to the coastal areas west of the Cascade and Coast mountains. The variety of definitions can be attributed to partially overlapping commonalities of the region's history, culture, geography, society, ecosystems, and other factors. The Northwest Coast is the coastal region of the Pacific Northwest, and the Northwest Plateau (also commonly known as " the Interior" in British Columbia and the Inland Northwest in the United St ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
