The Aleutian subduction zone

Part of Hall of Planet Earth.

The Aleutian Subduction Zone AMNH/R.Mickens

The Aleutian Trench, extending 2,900 kilometers from the Gulf of Alaska to Kamchatka, marks the place where the Pacific plate is being subducted beneath the North American plate. The two plates are approaching each other at about 6 centimeters a year. Subduction at this boundary has caused some of the largest earthquakes of the 20th century. The earthquakes become deeper from the trench northward. They define the top of the descending Pacific plate.