Transient fault slip in Guerrero, southern Mexico

The Guerrero region of southern Mexico has accumulated more than 5 m of relative plate motion since the last major earthquake. In early 1998, a continuous CPS site in Guerrero recorded a transient displacement. Modeling indicates that anomalous fault slip propagated from east to west along-strike of the subduction megathrust. Campaign GPS and leveling data corroborate the model. The moment release was equivalent to an M(w)greater than or equal to6.5 earthquake. No M >5 earthquakes accompanied the event, indicating the frictional regime is velocity-strengthening at the location of slip.