Warming now may be tipping isthmus of Panama into unparalleled drought
PostedApril 2, 2014
As dates in geologic history go, the formation of the slender land bridge that joins South America and North America is a red-letter one. More than once over the past 100 million years, the two great landmasses have been separated by deep ocean waters. The narrow section of Central America that now unites them–at its narrowest along the isthmus of Panama–changed not just the world map, but the circulation of oceans, the course of biologic evolution, and probably global climate. The tortured product of diverse forces, today’s version of the isthmus was probably fashioned by volcanism and movements of tectonic plates somewhere between 15 million and 3 million years ago.
Cornelia Class, a geochemist at Columbia University’s Lamont-Doherty Earth Observatory, and Esteban Gazel, a Lamont adjunct researcher now based at Virginia Polytechnic Institute, are looking into one of the most mysterious forces at work on this natural construction site: the Galápagos Plume.The plume is a long-lived hot upwelling of material from the deep earth that melts near the surface and has formed strings of volcanoes, both underwater and as ocean islands.