Scientists to map Chile earthquake site to capture fresh data

A team of scientists are all set to undertake an expedition to explore the rupture site of the 8.8-magnitude Chilean earthquake, which is one of largest quakes in recorded history.

The scientists are funded by the National Science Foundation (NSF) and affiliated with the Scripps Institution of Oceanography (SIO) at the University of California at San Diego.

The scientists hope to capitalize on a unique scientific opportunity to capture fresh data from the event.

They will study 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.

The Melville was conducting research off Chile when the earthquake struck.

"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," she added.

An important aspect of the rapid response mission involves swath multibeam sonar mapping of the seafloor to produce detailed topographic maps.

"Data from mapping the earthquake rupture zone will be made public soon after the research cruise ends," Morris said.

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, according to 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," he added.

Accoridng to 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."