The North Pacific Megatrend

摘要

Megatrends are trans-basin features comprised of fracture zones and seamount/island chains. They appear to be hot lines rather than isolated hot spots. The North Pacific Megatrend begins in Japan, crosses the trench in the form of the Geisha Guyots, skirts along the northern Mapmaker Seamounts, encompasses the Hawaiian chain, and passes through the Clipperton and Clarion fracture zones to the East Pacific Rise. The Central Pacific Megatrend bifurcates at the East Pacific Rise (Easter vortex), and the northern branch passes northward to meet the North Pacific Megatrend. The excess magma in the channel is directed eastwardly under the Galapagos chain to form the Cocos and Carnegie ridges, which pass onto the South American continent. This feature is surrounded by Precambrian mantle material and underlain by an earthquake band.