The Astoria Fan is a submarine fan. It has

sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand an ...

, radiating asymmetrically southward from the mouth of the

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 th ...

. From Astoria Canyon's mouth, the fan extends about to its western end, which is the

Cascadia Channel Cascadia Channel is the most extensive deep-sea channel currently known (as of 1969) of the Pacific Ocean. It extends across Cascadia Abyssal Plain, through the Blanco Fracture Zone, and into Tufts Abyssal Plain. Notably, Cascadia Channel has t ...

. The fan proper ends south of the canyon mouth, although its depositional basin extends southward another to the

Blanco Fracture Zone The Blanco Fracture Zone or Blanco Transform Fault Zone (BTFZ) is a right lateral transform fault zone, which runs northwest off the coast of Oregon in the Pacific Northwest of the United States, extending from the Gorda Ridge in the south to the ...

. Astoria Fan is generally

asymmetrical Asymmetry is the absence of, or a violation of, symmetry (the property of an object being invariant to a transformation, such as reflection). Symmetry is an important property of both physical and abstract systems and it may be displayed in pre ...

. It extends roughly west of the mouth of

, and about north, to

Willapa Channel Willapa may refer to: * Willapa people, an Athapaskan-speaking people in Washington, United States * Willapa River, river on the Pacific coast of southwestern Washington, United States * '' General Miles'', a ship * Willapa Electric Company, ...

. Others trace different dimensions. Headed west, the fan crosses the

continental shelf A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an island ...

, trending sinuously down to the base of the

continental slope A continental margin is the outer edge of continental crust abutting oceanic crust under coastal waters. It is one of the three major zones of the ocean floor, the other two being deep-ocean basins and mid-ocean ridges. The continental margin ...

. 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

. Ash from the

eruption of Mount Mazama Mount Mazama (''Giiwas'' in the Native American language Klamath) is a complex volcano in the state of Oregon, United States, in a segment of the Cascade Volcanic Arc and Cascade Range. Most of the mountain collapsed following a major erupti ...

has been found, in Astoria Fan. It may have been cut in the

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

. It appears the

Missoula Floods The Missoula floods (also known as the Spokane floods or the Bretz floods or Bretz's floods) were cataclysmic glacial lake outburst floods that swept periodically across eastern Washington and down the Columbia River Gorge at the end of the last ...

helped carve the fan. Astoria Fan merges into

, west of the Columbia River mouth. In the past, buried

channels Channel, channels, channeling, etc., may refer to: Geography * Channel (geography), in physical geography, a landform consisting of the outline (banks) of the path of a narrow body of water. Australia * Channel Country, region of outback Austral ...

appear to have connected the two.

Nearby submarine canyons

All of the following submarine canyons are near, headed north to south: *

Clayoquot Canyon Clayoquot is an anglicization of the Nuu-chah-nulth language name "Tla-o-qui-aht", one of the indigenous tribes of the region so named. It may refer to: * Clayoquot, British Columbia, historically also known as Port Cox, a community on Stubbs Isla ...

* Father Charles Canyon *

Loudon Canyon Loudon may refer to: Places In the United States: *Loudon, Massachusetts, formerly a constituent part of Otis, Massachusetts *Loudon, New Hampshire **Loudon (CDP), New Hampshire *Loudon, Tennessee *Loudon County, Tennessee *Loudoun County, Virgin ...

* Barkely Canyon *

Nitinat Canyon Ditidaht (also Nitinaht, Nitinat, Southern Nootkan) or diitiidʔaaʔtx̣ is a South Wakashan (Nootkan) language spoken on the southern part of Vancouver Island. Nitinaht is related to the other South Wakashan languages, Makah and the neighboring ...

Juan de Fuca Canyon Juan de Fuca Channel is a submarine channel off the shore of Washington state, United States and the Strait of Juan de Fuca. The geography of Juan de Fuca Channel The Juan de Fuca Channel is a submarine canyon running from the shelf break, o ...

Quileute Canyon Quileute Canyon (also ''Quillayute Canyon'') is a submarine canyon, off of Washington state, United States. Its location It is just north of Quinault Canyon. Quileute Canyon is offshore, from both La Push and Forks. Quillayute River pours into ...

Quinault Canyon The Quinault Canyon is a submarine canyon, off Washington state, in Olympic Coast National Marine Sanctuary. The area It lies opposite the Quinault Reservation. From the map, it is clear the Quinault River drains into the Pacific Ocean, opposit ...

Grays Canyon Grays or Greys may refer to: Places * Grays Bay, Nunavut, Canada * Grays, Essex, a town in Essex, England ** Grays railway station ** Grays School * Grays, Kent, a hamlet in Kent, England * Rotherfield Greys or Greys, a village in Oxfordshire, En ...

Guide Canyon A guide is a person who leads travelers, sportspeople, or tourists through unknown or unfamiliar locations. The term can also be applied to a person who leads others to more abstract goals such as knowledge or wisdom. Travel and recreation Ex ...

Willapa Canyon Willapa may refer to: * Willapa people, an Athapaskan-speaking people in Washington, United States * Willapa River, river on the Pacific coast of southwestern Washington, United States * ''General Miles'', a ship * Willapa Electric Company, an e ...

References

{{reflist

Nearby submarine canyons

See also

Local geography

References

External links and references