El Nino tectonic modulation in the Pacific Basin

摘要

The Easter and Juan Fernandez microplates, two counterclockwise-rotating microplates along the East Pacific Rise, are considered to be driven by downwelling tectonic vortices, as explained by a more recent geophysical theory known as the surge tectonic hypothesis. These twin microplates underlie the high pressure cell of the Southern Oscillation associated with El Nino. The Central Pacific Megatrend connects planetary-scale tectonic vortices underlying the El Nino Southern Oscillation (ENSO) pressure cells. It connects the East Pacific Rise across basin to the Banda Sea tectonic vortex. The Banda Sea is a triple-plate junction (between the Australian, Pacific, and Southeast Asian plates) just north of Darwin and is considered an upwelling mantle vortex underlying the low-pressure cell of ENSO. Active surge channels, or geostreams, defined by the newer surge model link these planetary-scale tectonic vortices. The original lead for a trans-Pacific megatrend was from the works of the late A.A. Meyerhoff. He brought attention to this region with the publication of Surge Tectonics: A New Hypothesis of Earth Dynamics (1992, 1996). His insight was based on many years of field study for oil exploration in Southeast Asia, the former USSR, and China, as well as on his background in fluid dynamics. In addition, high-pass-filtered satellite altimetry data from the Geodetic Earth-Orbiting Satellite (GEOSAT) reveal across-basin trends in the gravity geoid.