Constraints on slow earthquake dynamics from a swarm in central italy.

Several clustered slow earthquakes have been recorded by a geodetic interferometer in central Italy. The strain rise times of the events range from tens to thousands of seconds, and the seismic moment scales with the square root of the rise time. This scaling law contrasts with the conservative assumption of constant rupture velocity in fault modeling but is consistent with the occurrence of a slow rupture propagation analogous to heat diffusion in a slab.