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Caltech

Seismo Lab Brown Bag Seminar

Wednesday, April 3, 2024
12:00pm to 1:00pm
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South Mudd 254
Investigating the role of local, contact scale temperature on flash heating in granite
Monica Barbery, Brown University,

The slip instability and dynamic rupture that leads to earthquakes is regarded as a frictional phenomenon, and an important problem is characterizing the frictional weakening of faults at earthquake slip rates. Dynamic weakening by flash heating occurs at highly-stressed asperity contacts as slip rates approach seismic rates, and the magnitude of weakening increases with surface temperature. In this talk, I will present results from rock friction experiments using a high-speed biaxial apparatus equipped with a high-speed infrared camera to explore the role of surface temperature on flash heating. We combined 1-D thermal models with measured surface temperature to constrain the evolution of normal stress and flash temperature at the mm-scale, and incorporated this evolution into a flash-weakening model. Model predictions are improved when inhomogeneous normal stress is considered in combination with micron and mm sized asperity contacts.