Skip to main content
U.S. flag

An official website of the United States government

Brittle and ductile friction and the physics of tectonic tremor

January 1, 2011

Observations of nonvolcanic tremor provide a unique window into the mechanisms of deformation and failure in the lower crust. At increasing depths, rock deformation gradually transitions from brittle, where earthquakes occur, to ductile, with tremor occurring in the transitional region. The physics of deformation in the transition region remain poorly constrained, limiting our basic understanding of tremor and its relation to earthquakes. We combine field and laboratory observations with a physical friction model comprised of brittle and ductile components, and use the model to provide constraints on the friction and stress state in the lower crust. A phase diagram is constructed that characterizes under what conditions all faulting behaviors occur, including earthquakes, tremor, silent transient slip, and steady sliding. Our results show that tremor occurs over a range of ductile and brittle frictional strengths, and advances our understanding of the physical conditions at which tremor and earthquakes take place.

Citation Information

Publication Year 2011
Title Brittle and ductile friction and the physics of tectonic tremor
DOI 10.1029/2011GL046866
Authors Eric G. Daub, David R. Shelly, Robert A. Guyer, P.A. Johnson
Publication Type Article
Publication Subtype Journal Article
Series Title Geophysical Research Letters
Index ID 70034732
Record Source USGS Publications Warehouse
USGS Organization Volcano Science Center