Contribution of the 2010 Maule Megathrust Earthquake to the Heat Flow at the Peru-Chile Trench

Abstract

The 2010 Maule earthquake was a megathrust event that occurred along the Peru–Chile Trench. The earthquake source can be modelled as a fault with two asperities with different areas and strengths. By employing a discrete fault model, where asperities are the basic elements, the event can be described as a sequence of three dynamic modes involving simultaneous asperity slip. Interaction between asperities by mutual stress transfer plays a crucial role during fault slip. With a careful choice of values for the model parameters, the mode durations, the slip distribution, the seismic moment rate and the final moment calculated from the model are found to be consistent with the observed values. An important amount of frictional heat is produced by an event of this size and is calculated by summing up the contributions of each asperity. The seismic event produces a heat pulse propagating through the Earth’s crust and contributing to the average heat flow in the region. The calculated heat production is equal to about 2×1017 J and the peak value of the heat pulse is equal to 6×10−3 mW m−2 or about 10−4 of the average surface heat flow density, with a characteristic diffusion time in the order of 106 a.