Development of an Instrument to Allow Rotary-Shear Friction Experiments at High-Pressure and Seismic Slip Rates

Brown University, Providence RI

Investigators

Abstract

This project will develop a new instrument that will be able to measure the frictional properties of rock that is simultaneously subjected to high confining pressure and slipping at rates typical of faults during earthquakes. No machine like this currently exists anywhere in the world. As with any development of new instrumentation and procedures, there is considerable benefit to a wide range of interested parties if the project is a success. The individuals participating in the project, including an early career scientist, will benefit from the professional growth represented by overcoming the challenges the project presents. The increase in understanding of the physics of the earthquake source made possible by the new experimental capability will benefit many earthquake scientists and lead to a better understanding of the generation of seismic waves, including those producing strong damaging ground motions. Experimental rock deformation has already made important contributions to our understanding of earthquake physics, but critical questions remain that can only be addressed by laboratory experiments. Although there are other ways in which such experiments are relevant to understanding earthquakes, this project focuses on friction, since friction plays such an important role in understanding the occurrence of earthquakes and what takes place at the earthquake source. Gaining this understanding is not only of intrinsic scientific interest, much of the greatest uncertainty in understanding when and why earthquakes occur and the contributions of the earthquake source to damaging strong ground motions is due to our limited understanding of friction on faults.