Anders Zorn paintings

Anders Zorn paintings
Anne-Francois-Louis Janmot paintings
This is a difficult area for scientists to study, because they can't put their instruments 150 miles below the ground, so they are left with indirect ways of studying it, such as rocks heaved to the surface during a violent eruption long, long ago. But there is one tool that lends itself well to determining what lies so far beneath the surface — earthquakes.When a fault moves, it sends out seismic shock waves that travel clear through the Earth. By measuring the time it takes those waves to travel through certain areas, scientists are able to create images through a process known as "seismic tomography," which is actually quite similar to CAT scans used in medical imaging.But since seismic stations are normally spread all over the planet, usually at great distances from each other, the images are very low in resolution, offering researchers the big picture, but few details.