Aleutian Trench

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Map of the Aleutian Trench

The Aleutian Trench (or Aleutian Trough)[1] is an oceanic trench along a convergent plate boundary which runs along the southern coastline of Alaska and the Aleutian islands. The trench extends for 3,400 km from a triple junction in the west with the Ulakhan Fault and the northern end of the Kuril–Kamchatka Trench, to a junction with the northern end of the Queen Charlotte Fault system in the east. It is classified as a "marginal trench" in the east as it runs along the margin of the continent. The subduction along the trench gives rise to the Aleutian arc, a volcanic island arc, where it runs through the open sea west of the Alaska Peninsula. As a convergent plate boundary, the trench forms part of the boundary between two tectonic plates. Here, the Pacific Plate is being subducted under the North American Plate at a dip angle of nearly 45°. The rate of closure is 3 inches (76 mm) per year.[2]

Trench morphology[edit]

The north side of the trench slopes 3°–4° and the south side 1°–4°.[3] The deepest part of the Aleutian trench has been measured at 7,822 metres (25,663 ft) at 51.21°N, 174.83°E.,[4] located about 145 km SSW of Buldir Island.

Center pressure: 10,762 pounds per square inch (732.3 atm; 74.20 MPa).[5] Variations in total magnetic intensity (residual) of more than 600 γ (600 nanoteslas) were found in the center of the trench and more than 1100 γ on the southern flank.[6]

Associated seismicity[edit]

The subduction of the Pacific Plate below the North American Plate along the Aleutian Trench is associated with numerous earthquakes. Several of these earthquakes are notable for their size and/or associated tsunamis.


  1. ^ Webster's New Geographical Dictionary. Springfield, Massachusetts: Merriam-Webster Inc. 1984. pp. 30. ISBN 0-87779-446-4.
  2. ^ "Aleutian Trench". Archived from the original on February 25, 2014. Retrieved May 4, 2012.
  3. ^ "Profile of Aleutian Trench". Retrieved May 6, 2012.
  4. ^ "North Pacific Ocean Bering Sea (Southern Part)". NOAA Chart 513 7th Edition. June 2004. Retrieved 29 November 2012.
  5. ^ "Aleutian Trench Data". Archived from the original on February 9, 2013. Retrieved May 6, 2012.
  6. ^ "Magnetic Information". Retrieved May 6, 2012.
  7. ^ USGS - Historic Earthquakes, Unimak Island Archived 2013-07-31 at the Wayback Machine
  8. ^ "USGS - Historic Earthquakes, 1957 Andreanof Islands". Archived from the original on 2011-06-08. Retrieved 2017-08-28.
  9. ^ "USC Tsunami Research Group". Archived from the original on 2013-06-05. Retrieved 2013-07-18.
  10. ^ USGS - Historic Earthquakes
  11. ^ "M 7.7 - 198km ESE of Nikol'skoye, Russia". Retrieved 2017-07-18.
  12. ^ "M 7.9 - 280 km SE of Kodiak, Alaska". Retrieved 2018-01-23.

External links[edit]

Coordinates: 52°N 172°E / 52°N 172°E / 52; 172