The 1,800-mile thick mantle under the Pacific Ocean contains rising plumes of hot rock that fan out at the surface to stationary hotspots, where they generate island chains as Earth’s crust moves due to plate tectonics. Scott French image.

Seismologists from University of California, Berkeley, have come up with an interesting project. They’ve analyzed paths of seismic waves and based on that created the first-ever detailed 3D map of the Earth’s interior.

The model shows mantle plumes (where the hot rock flows) starting at the bottom of the core-to-mantle boundary and climbing to the top, where they connect to volcanic hotspots in the Earth’s crust. The model precisely connected volcanic island chains like Hawaii, Samoa and Iceland. Of course it isn’t perfect. It didn’t link plumes to some volcanoes, such as the one at Yellowstone National Park but still it is the most precise scan of the Earth’s interior ever made.

Most of the known volcanic hotspots are linked to plumes of hot rock (red) rising from two spots on the boundary between the metal core and rocky mantle 1,800 miles below Earth’s surface.

Previous attempts to map mantle plumes have detected pockets of hot rock rising in areas where plumes have been predicted, but it was unclear whether they were connected to volcanic hotspots at the surface or at the roots of the plumes, deep below the surface of the planet.

Creating this kind of high-resolution CT of Earth, requires significant computing resources. Scientists used very accurate numerical simulations of how seismic waves travel through the mantle, and compared their predictions to the ground motion actually measured by detectors around the globe. The analysis required 3 million CPU hours on supercomputers, and tool couple of weeks of computing.

It is interesting that we are thinking about exploring Mars but we still now so little about what’s beneath us.

source: Berkeley News