3 Geological Features

3 GEOLOGICAL FEATURES Mara Sprang

The Hawaiian Islands were formed by volcanic activity from an undersea magma source called a hotspot. As the tectonic plate underneath most of the Pacific Ocean moves northwest the hotspot stays in the same place and slowly creates new volcanoes, making the islands larger. The only active volcanoes are located on the southern half of the large island. Hawaii is located in the middle of the North Pacific Ocean, about 3,200 kilometers from the coast of the Continental United States.

HAWAII

MT. RAINIER Mt. Rainer is a stratovolcano that is very eroded and has glaciers on its slopes. Mt. Rainier is associated with the subduction of the Juan de Fuca and Gordo plates beneath the North American plate, forming the Cascadia Subduction Zone. As the subducting plates heated, they formed magma, which rose to the surface and punched out as a stratovolcano. Mt. Rainier is located in west-central Washington.

SAN ANDREA'S FAULT The San Andreas Fault began to form when the area between the Pacific Plate and the Farallon Plate was beginning to reach the subduction zone off the west coast of North America. As the motion between the Pacific and North American Plates was different from the motion between the Farallon and North American Plates, the spreading ridge began to be subducted creating a new motion and a new style of deformation along the plate boundaries. The pacific plate moves northwest the North American plate moves southeast because of plate tectonics. The San Andreas Fault is located just west of the central California Valley