Title

Low Coseismic Friction on the Tohoku-Oki Fault Determined from Temperature Measurements

Abstract

The frictional resistance on a fault during slip controls earthquake dynamics. Friction dissipates heat during an earthquake; therefore, the fault temperature after an earthquake provides insight into the level of friction.The Japan Trench Fast Drilling Project (Integrated Ocean Drilling Program Expedition 343 and 343T) installed a borehole temperature observatory 16 months after the March 2011 moment magnitude 9.0 Tohoku-Okiearthquake across the fault where slip was ~50 meters near the trench. After 9 months of operation, thecomplete sensor string was recovered. A 0.31°C temperature anomaly at the plate boundary faultcorresponds to 27 megajoules per square meter of dissipated energy during the earthquake. The resulting apparent friction coefficient of 0.08 is considerably smaller than static values for most rocks.

Publication Date

12-6-2013

Journal or Conference Title

Science

Volume

342, Number 6163

Pages

1214–1217

Publisher

American Association for the Advancement of Science (AAAS)

Digital Object Identifier (DOI)

10.1126/science.1243641

Document Type

Journal Article