The 2014 Juan Fernández microplate earthquake doublet: Evidence for large thrust faulting driven by microplate rotation

On October 9, 2014, a Mw 7.1–6.7 seismic doublet occurred at the Juan Fernández microplate, close to triple junction with Pacific and Nazca plates. The 7.1 earthquake is largest ever have been recorded in region. Its thrust focal mechanism also unusual for region, although northern part of microplate expected undergo compression. region remote seismological data limited station ~600 km distance on Easter Island teleseismic observations events. We use combination advanced techniques overcome lack local resolve source parameters its aftershock sequence, being able reconstruct chronology sequence geometry affected fault segments. Our results depict complex characterized by interplay strike-slip earthquakes along different structures, including second, reversed strike slip-thrust November 2014. Seismicity within only late migrated northward, towards boundary. first doublet, whose rupture kinematic well explained stress changes imparted subevent second one, may activated unmapped E-W NE-SW faults or an internal curved pseudofault, attributed long-term rotation microplate. Few large, are observed taking place vicinity mapped compressional ridges. suggest that stresses boundary partially accommodated aseismically. However, occasional occurrence impulsive earthquakes, considerable tsunamigenic potential, poses relevant hazard islands South