hawaiian islands and volcanic island arcgreenspun.com : LUSENET : Introductory Geology, Oswego State : One Thread
Why is Hawaii a volcanic island arc even though it is in the center of a plate.
-- Luke Bickford (MBick4@aol.com), February 01, 2001
The Hawaiian Islands are not located at a subduction zone. They are sitting in the middle of the Pacific plate, far away from any plate boundary.
-- Sharon Gabel (firstname.lastname@example.org), February 05, 2001.
because the hawaian volcanic arc is a subduction zone. one plate sinks beneath the other, it is heated by the hot mantle and the water and other impurites "boil" up and off the suducted plate, heating and melting the materials above , forceing them to the surface, makeing a volcano or a series of them.
-- nathaniel miller (email@example.com), February 05, 2001.
Within the mantle there are plumes; mantle that turns into slender, rising magma which sometimes reaches the surface, explaining how volcanoes can form without being in the vicinity of a plate boundary. These plumes are also mostly basalt, the rock that makes up hawaii.
-- AJ Spado (firstname.lastname@example.org), February 06, 2001.
There is a "hot spot" right under the hawaiian Islands, which makes the volcanoes that make up the island. This has nothing to do with it's location on a plate.
-- Paul Trygub (email@example.com), May 21, 2003.