Magnitude 9.0 earthquake off the west coast of Northern Sumatra. Yellow circles indicate aftershocks. Image courtesy USGS.

When the devastating earthquake and tsunami struck in South Asia on Dec. 26, Rensselaer professor Rob McCaffrey watched the story unfold with knowing concern. For 25 years the geophysics professor has been monitoring earthquake activity and plate convergence at subduction zones in Indonesia, including the Sumatra subduction zone where the recent magnitude 9 earthquake occurred.

"Large earthquakes are common in South Asia, generating smaller tsunamis every few decades. But a magnitude 9 is very rare," said McCaffrey. "This is about as big as it could get along that fault line. It will likely be many centuries before a magnitude 9 quake hits that section of the fault again, but a quake of similar size could occur along the fault south of Java."

McCaffrey's research interests include the analysis of geological, seismological, gravity, and geodetic data from convergent margins with attention to the structure, tectonics, and dynamics of subduction and collision. Regions studied include Indonesia, New Guinea, Taiwan, Panama, Central Asia, and the United States. McCaffrey uses teleseismic body waves and microearthquake networks to constrain the depths and mechanisms of earthquakes in order to understand collision processes. He also uses the Global Positioning System (GPS) to measure crustal formation and obtain a greater understanding of geologic processes.

"We examine earthquake statistics to understand what factors control when and where large earthquakes occur, measuring temperature of the faults, magnitude distributions, slip rates, etc.," said McCaffrey. "The goal is to see how much we can learn about future earthquakes from what has happened in the past."

National Geographic.com, Nature.com, The New York Times, and New Scientist all quoted McCaffrey in articles about the disaster. He was profiled in the Albany Times Union, and responded to listener questions on Northeast public radio station WAMC.

For more information, go to  http://www.rpi.edu/~mccafr/sumatra04/.

Published January 18, 2005