ABSTRACT
The more slowly a fault slips, the less efficiently it generates seismic waves. The distinguishing characteristic of slow earthquakes is that the waves they generate are weak, particularly at high frequencies, compared to ordinary earthquakes. New seismic and geodetic earthquake monitoring networks installed over the past decade have led to a salmagundi of newly discovered, unusually slow seismic phenomena, including: silent earthquakes, low- frequency earthquakes, Very Low Frequency earthquakes, and deep non-volcanic tremor. We find that all of these phenomena are different manifestations of a single underlying process, viz. slow slip on the deep extension of seismogenic faults, and that slow earthquakes obey a characteristic scaling relationship that is distinct from ordinary earthquakes. Ordinary earthquake scaling is governed by wave-mediated stress transfer, but other physical processes must be responsible for putting the brakes on slow earthquakes.