Velocity‐weakening behavior of Westerly granite at temperature up to 600°C

The deep limit to seismicity in continental crust is believed to be controlled by a transition from velocity‐weakening to velocity‐strengthening friction based on experimental measurements of the rate dependence of friction at different temperatures. Available experimental data on granite suggest a transition to stable creep at about 350°C (∼15 km depth). Here we present results from unconfined experiments on Westerly granite at both dry and...