Scientists assess Central American earthquake risk

November 4, 2006

AUSTIN, Texas—In some places earthquakes are not just an academic problem. During the 20th century earthquakes killed more than 30,000 people in Central America, which forms part of the Pacific Ring of Fire, a system of subduction zones and strike-slip faults encircling the basin of the Pacific Ocean. In Central America subduction produces volcanoes on land and powerful earthquakes both offshore and on the mainland. The earthquakes that occur on land are stronger than those located offshore, and more dangerous since most people live in the fertile central valley adjacent to the volcanoes.

In May and June 2006, with funding from the Jackson School and the Subduction Factory program of the National Science Foundation (NSF), UTIG’s Kirk McIntosh and Paul Mann teamed up with colleagues from the Department of Geological Sciences and the university’s Department of Geography to investigate the faults responsible for volcanic-front earthquakes near Lake Managua and Lake Nicaragua. Because lakes continually collect sediments, careful studies of the age of faulted lake sediments can provide a history of the timing and character of major earthquakes.

The team used rented ferry boats, adapting them for their geophysical surveys and lake coring campaigns. Prior to the project neither lake had been thoroughly surveyed. The fault patterns mapped challenge all previous predictions for faults beneath Lakes Nicaragua and Managua, which cover much of the country. The researchers are currently engaged in correlating the geophysical survey results with the core data. They will present their preliminary findings at the December meeting of the American Geophysical Union.

For information about the NicLakes project, contact co-PIs Kirk McIntosh, 512-471-0480 or Paul Mann, 512-471-0452.

For more information about the Jackson School, contact J.B. Bird at jbird@jsg.utexas.edu, 512-232-9623.