Breakthrough Achieved in Explaining Why Tectonic Plates Move the Way They Do
A team of researchers including Scripps Institution of Oceanography, UC San Diego geophysicist Dave Stegman has developed a new theory to explain the global motions of tectonic plates on the earth's surface. The new theory extends the theory of plate tectonics - a kinematic description of plate motion without reference to the forces behind it - with a dynamical theory that provides a physical explanation for both the motions of tectonic plates as well as motion of plate boundaries. The new findings have implications for how scientists understand the geological evolution of Earth, and in particular, the tectonic evolution of western North America, in the past 50 million years. The research, led by Monash University's Wouter Schellart, is published in the July 16 issue of the journal Science. Read more
A three-dimensional model of our planet's plate tectonics could help to explain why the Andes mountain range is taller than geologists would predict: it could all be down to the long length of the South American continent. The highest mountain range on our planet — the Himalayas — was formed by the massive collision of two continental plates. But the Andes were formed where an oceanic plate slides beneath a continent. While this 'subduction' process is expected to create mountains through a crumpling of the continental plate above, it's perplexing why the peaks of the central Andes stand at an average height of 4 kilometres. Previous calculations based on models of plate tectonics have at times suggested they ought to be half that height.
The Digital Tectonic Activity Map (DTAM) is a new visualization tool for both researcher and educator alike to better understand tectonic activity of our planet for the past 1 million years. DTAM 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. Macroscopic structural features were integrated via field studies from various researchers, space geodesy, and space-borne imagery (e.g. astronaut photography, Landsat). This integrative technique provides a new and unique visualization tool that presents an actual representational view of global tectonics rather than the traditional schematic illustrations (i.e. plate maps) of the past.