Wednesday, December 27, 2006

Life on the Edge

The residents of Taiwan experienced several earthquakes over the past few days. This is a common occurance in that island nation which sits on the junction of the Philippine and Eurasian plates; the former is moving westward, colliding with and subducting beneath the latter. The island of Taiwan has formed just west of the subduction zone as ocean sediments are scraped off the plunging oceanic plate and as volcanoes form and erupt in response to melting of the deeper plate segments.

The process continues today as it does across the Pacific Rim. The Aleutians of Alaska, the islands off east Asia, the Philippines and the Indonesian Archipelago are all "island arcs," having formed parallel to an oceanic trench (a deep crease in the ocean floor formed by the subducting plate). Earthquakes and volcanic eruptions are just part of life in these areas.