Convergent plate boundaries are also called subduction zones and are typified by the Aleutian Trench, where the Pacific Plate is being subducted under the North American Plate. The best known example is the earthquake-prone San Andreas fault zone of California, which marks the boundary between the Pacific and North American Plates. The great majority of the world's earthquakes and active volcanoes occur near the boundaries of the Earth's shifting plates.
Why then are the Hawaiian volcanoes located near the middle of the Pacific Plate, more than 2, miles from the nearest plate boundary? In , J. Tuzo Wilson, a Canadian geophysicist,. Technical Announcements. Employees in the News. Emergency Management. Survey Manual. Japan—only 63 million years away! Advertising like that would put a shipping company out of business, but the Plate Tectonic Express has no competitors when it comes to moving continents and oceanic plates around the globe.
Many readers are familiar with the theory of plate tectonics, which describes the Earth's crust as a series of plates moving from zones of upwelling oceanic ridges toward subduction zones oceanic trenches. Also familiar is the idea that the Hawaiian Island chain has formed because the Pacific plate is moving slowly across a hot spot.
The hot spot, rooted deep in the Earth's mantle, drives the melting that ultimately leads to volcanism and island building. Old islands drift beyond the hot spot and new islands form. Where will the Big Island go as it moves from the focus of heat and volcanism?
Presently the Hawaiian Islands and our part of the Pacific plate are moving northwest at about mm 4 in. The trajectory of motion points toward Hokkaido on the northern part of the Japanese Island chain, 6, km 3, mi away. The youngest seamount of the Hawaiian chain is Loihi, which presently is erupting from its summit at a depth of meters. Image courtesy of U. Geological Survey. In areas where the plates come together, sometimes volcanoes will form.
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