CAL TECH : NEW TECHNOLOGY TO DETECT EARTH'S PLATES BELOW THE SURFACE

CAL TECH : NEW TECHNOLOGY - EARTH'S PLATES 

Excerpts:  Caltech researchers have developed a new method to study the earth's structure deep beneath the surface, at the boundary between Earth's brittle crust and the underlying mantle, a region called the Mohorovičić discontinuity—Moho for short.

.....On continents, the Moho can be found at depths ranging between 20 and 70 kilometers beneath the surface; in Southern California, the Moho is around 45 kilometers belowground. Attempts had been made to image it using conventional seismometers, but these efforts either yield low-resolution results, on the scale of tens of kilometers, or were prohibitively expensive. With the DAS method, researchers can easily observe the structure of the Moho over large regions at a resolution of a kilometer, providing a far more detailed look at this geologically important region.