Scientists at the University of California, San Diego are undertaking an expedition to explore the rupture site of the 8.8-magnitude Chilean earthquake.

The team hopes to capitalize on a unique opportunity to capture fresh data from the event by studying changes in the seafloor that resulted from movements along faults and submarine landslides.

The "rapid response" expedition, called the Survey of Earthquake And Rupture Offshore Chile, will take place aboard the research vessel Melville.

Scientists will map the rupture site of the 8.8-magnitude earthquake in Chile.

Credit: Jared Kluesner, David Sandwell, Scripps Institution of Oceanography, UCSD

"This rapid response cruise is a rare opportunity to better understand the processes that affect the generation and size of tsunamis," said Julie Morris, NSF division director for Ocean Sciences. "Seafloor evidence of the quake will contribute to understanding similar earthquake regions worldwide."

The primary focus of the research will be mapping the seafloor with swath multibeam sonar to produce detailed topographic maps. Data from mapping the earthquake rupture zone will be made public soon after the research cruise ends.

The new data will be compared with pre-quake data taken by scientists at Germany's Leibniz Institute of Marine Sciences (IFM-GEOMAR).

Several years ago IFM-GEOMAR researchers conducted a detailed multibeam mapping survey off Chile. Their data will be valuable for comparisons with the new survey to expose changes from the earthquake rupture, say researchers.

"We'd like to know if the genesis of the resulting tsunami was caused by direct uplift of the seabed along a fault, or by slumping from shaking of sediment-covered slopes," said Dave Chadwell, an SIO geophysicist and chief scientist of the expedition.

"We will look for disturbances in the seafloor, including changes in reflectivity and possibly shape, by comparing previous data with the new [rapid response] data."

"This is a unique case in which we have the shipboard assets, the scientific agenda and the funding all in place," said Bruce Appelgate, associate director for Ship Operations and Marine Technical Support at SIO. "The earthquake was a tragedy for the people of Chile, but we hope this opportunity enables important new discoveries that can help us plan for future events."