Reconsidering earthquake scaling

Gomberg, J, Wech A, Creager K, Obara K, Agnew D.  2016.  Reconsidering earthquake scaling. Geophysical Research Letters. 43:6243-6251.

Date Published:



interface, mechanism, models, slow slip events, tremor


The relationship (scaling) between scalar moment, M-0, and duration, T, potentially provides key constraints on the physics governing fault slip. The prevailing interpretation of M-0-T observations proposes different scaling for fast (earthquakes) and slow (mostly aseismic) slip populations and thus fundamentally different driving mechanisms. We show that a single model of slip events within bounded slip zones may explain nearly all fast and slow slip M-0-T observations, and both slip populations have a change in scaling, where the slip area growth changes from 2-D when too small to sense the boundaries to 1-D when large enough to be bounded. We present new fast and slow slip M-0-T observations that sample the change in scaling in each population, which are consistent with our interpretation. We suggest that a continuous but bimodal distribution of slip modes exists and M-0-T observations alone may not imply a fundamental difference between fast and slow slip.