“…This is in good agreement with the bulk temperature increase estimated along the slipping zone at the main frictional instability. If the heat production is (Beeler et al, 2008; Lachenbruch & Sass, 1980)
an estimate of the bulk temperature increase in the slipping zone during the experiments can be computed numerically using the approximation (Carslaw & Jaeger, 1959; Nielsen et al, 2008; Figure S6)
(with, for basalts, thermal diffusivity κ = 0.012 cm 2 /s; Hanley et al, 1978), specific heat capacity Cp = 898 J · kg −1 · K −1 (Waples & Waples, 2004), and density ρ = 2,960 kg/m 3 ). The numerical solution revealed indeed the achievement of bulk temperatures of several hundred degrees Celsius once the main instability was triggered, as shown in Figure S6.…”