Laboratory experiments shearing granular assemblies show similar dilation behavior to fast and slow earthquakes

The data are from a suite of friction experiments performed on simulated fault gouges comprised of glass spheres, sheared in a ring-shear arrangement. We simultaneously recorded detailed mechanical data, acoustic emission and precise thickness variation of dense granular assemblies at an ultra-high sampling rate of 10 MHz. Experiments were performed at four effective normal stress of 900 kPa, 1100 kPa, 1300 kPa, and 1500 kPa. The shear velocity was set to 1.5 °/min.