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The seismic cycle requires that faults strengthen (heal) between earthquakes, and the rate of this healing process plays a key role in determining earthquake stress drop^,,,, rupture characteristics, and seismic scaling relations^,,,. Frictional healing (as evidenced by increasing static friction during quasi-stationary contact between two surfaces,^,,,,) is considered the mechanism most likely to be responsible for fault strengthening,,,. Previous studies, however, have shown a large discrepancy between laboratory and seismic (field) estimates of the healing rate,,,,; in the laboratory, rock friction changes by only a few per cent per order-of-magnitude change in slip rate, whereas seismic stress drop increases by a factor of 2 to 5 per order-of-magnitude increase in earthquake recurrence interval. But in such comparisons, it is assumed that healing and static friction are independent of loading rate. Here, I summarize laboratory …