Moore Foundation grant funds study of Tohoku earthquake fault

UCSC seismologist Emily Brodsky leads analysis of temperature data from international expedition to drill into the fault zone off the coast of Japan

emily brodsky
Emily Brodsky

The Gordon and Betty Moore Foundation has awarded a grant of more than $750,000 to UC Santa Cruz seismologist Emily Brodsky. The grant funds Brodsky's research to better understand the fault that caused the devastating Tohoku earthquake and tsunami, which struck Japan in March 2011.

Brodsky, a professor of Earth and planetary sciences, helped organize the Japan Trench Fast Drilling Project (JFAST), which successfully drilled across the Tohoku earthquake fault earlier this year and installed a temperature observatory on the fault. The observatory allows scientists for the first time to measure the frictional heat produced by the fault slip of a great subduction-zone earthquake.

Earthquakes occur as giant plates in the Earth's crust grind past each other. Tectonic forces push the plates forward, while friction on the faults between plates holds them back. According to Brodsky, the lack of measurements of the frictional force during the sliding motion of an earthquake is one of the major impediments to progress in earthquake science.

"Observing and analyzing the temperature on the fault following the recent magnitude 9 Tohoku earthquake provides a unique and probably never-again achievable window into this critical value," Brodsky said. "What we learn will inform and prepare us for the next earthquakes, including the one predicted for the Cascadian subduction zone that lies along the coast of Oregon and Washington."

With the Moore Foundation's support, Brodsky will analyze the temperature data recovered from the Tohoku observatory for a period of three years. She will be working with Patrick Fulton, currently a postdoctoral fellow at the University of Texas, Austin, who will relocate to UCSC to join Brodsky on this project.

The JFAST project involves an international team of scientists. The Integrated Ocean Drilling Program (IODP) moved with unprecedented speed and collaboration to organize the expedition of the state-of-the-art drilling ship Chikyu. The successful drilling into the Tohoku fault, 7 kilometers below the surface of the ocean, and installation of the temperature observatory were unprecedented accomplishments. Construction of the observatory, as well as ship operation costs, were funded by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) and IODP.