Map of World Hotspots

Map of World Hotspots Most of the worlds  volcanism  occurs on plate boundaries. Hotspot is the name for a center of volcanism that is exceptional. Map of World Hotspots Click the image for the full-size version. Image courtesy Gillian Foulger According to the original theory of hotspots, from 1971, hotspots represent mantle plumes- blobs of rising hot material from the base of the mantle- and make up a fixed framework independent of plate tectonics. Since that time, neither supposition has been confirmed, and the theory has been greatly adjusted. But the concept is simple and appealing, and the majority of specialists are still working inside the hotspot framework. Textbooks still teach it. The minority of specialists seeks to explain hotspots in terms of what I might call advanced plate tectonics: plate fracturing, counterflow in the mantle, melt-producing patches and edge effects. This map shows the hotspots listed in an influential 2003 paper by Vincent Courtillot and colleagues, which ranked them according to a set of five widely accepted criteria. The three sizes of symbols show whether the hotspots had high, medium or low scores against those criteria. Courtillot proposed that the three ranks correspond to an origin at the base of the mantle, the base of the transition zone at 660 kilometers depth, and the base of the lithosphere. There is no consensus on whether that view is valid, but this map is handy for showing the names and locations of the most commonly mentioned hotspots. Some hotspots  have obvious names, like Hawaii, Iceland and Yellowstone, but most are named for obscure ocean islands (Bouvet, Balleny, Ascension), or seafloor features that in turn got their names from famous research ships (Meteor, Vema, Discovery). This map should help you keep up during a talk aimed at specialists.