Seeing Beneath The Surface of Plate Tectonics
The Earth’s outer layer is broken into interacting plates whose motion at the surface generates earthquakes, creates volcanoes and builds mountains. The plates’ fundamental properties and the mechanisms that cause them to move and drift are the subjects of intense study by geoscientists. New research published Feb. 27 in the early online edition of the journal Science contributes to solving the puzzle.
The new research, by scientists at UCLA and a colleague now at the University of Maryland, uses seismology to study the Pacific plate — one of several major plates — and determine its thickness and its relationship to deformation of the underlying rocks.
The researchers used a method called seismic tomography, similar to medical imaging methods such as CT Scans. It uses recordings of the seismic waves generated by earthquakes to create images that capture variations in wave speed inside the Earth. These variations can reveal different subsurface layers, and help scientists discover the temperature and chemistry of the rocks. This layering can be seen with different kinds of seismic data, but a major challenge in seismology is to compare datasets that image the same structure with different methods.
“We overcame this challenge by trying to push the observational science to the highest resolutions, allowing us to more readily compare observations across datasets,” said Nicholas Schmerr, Assistant Research Scientist in the UMD Geology Department. Schmerr, an expert in seismic tomography datasets, is a co-author of the research.
“Our research enables us to image the interior of the plate, and helps us figure out how it formed and evolved,” said Caroline Beghein, assistant professor in UCLA’s Department of Earth, Planetary and Space Sciences, and lead author of the Science paper.
-University of Maryland College of Computer, Mathematical and Natural Sciences-
