Plate Tectonics on the Birthday of Alfred Wegener
November 01, 2000
Today marks the 120th birthday of German scientist, meteorologist and geophysicist Alfred Wegener, born on this day in 1880. Wegener formulated the first complete statement of the continental drift hypothesis, but was the focus of much ridicule among professional geologists who demanded a mechanism that could make the continents "plow around in the mantle," as one critic put it. It was not until the mid-1950s that a series of confirming discoveries in oceanography and paleomagnetism finally convinced most scientists that continents do indeed move. Convection currents in the molten magma of the upper mantle are the likely source of forces moving the continents.
The Digital Tectonic Activity Map (DTAM) above was produced by Paul Lowman and colleagues at NASA GSFC. It is a Geographical Information System (GIS) that displays a realistic synoptic view of present global tectonism by filling in the cartographic gap between conventional geological maps and plate reconstruction maps. The DTAM was created using current global datasets of seismicity, volcanism, and plate motions that were integrated with topography and bathymetry measurements derived from satellite gravity data.