Areas prone to slow slip events impede earthquake rupture propagation and promote afterslip

Frédérique Rolandone (1) , Jean-Mathieu Nocquet (2) , Patricia Mothes (3) , Paul Jarrin (3) , Martin Vallée (4) , Nadaya Cubas (5) , Stephen Hernandez (3) , Morgan Plain (3) , Sandro Vaca (3) , Yvonne Font (2)

1 DéSIR - Déformations, sismotectonique, imagerie, relief
2 GEOAZUR 6526 - Géoazur
3 Instituto Geofísico
4 IPGP - Institut de Physique du Globe de Paris
5 LGM - Laboratoire de Géosciences Marines

At subduction zones, transient aseismic slip occurs either as afterslip following a large earthquake or as episodic slow slip events during the interseismic period. Afterslip and slow slip events are usually considered as distinct processes occurring on separate fault areas governed by different frictional properties. Continuous GPS (Global Positioning System) measurements following the 2016 Mw (moment magnitude) 7.8 Ecuador earthquake reveal that large and rapid afterslip developed at discrete areas of the megathrust that had previously hosted slow slip events. Regardless of whether they were locked or not before the earthquake, these areas appear to persistently release stress by aseismic slip throughout the earthquake cycle and outline the seismic rupture, an observation potentially leading to a better anticipation of future large earthquakes

Domaines: Sciences de la Terre

Frédérique Rolandone, Jean-Mathieu Nocquet, Patricia Mothes, Paul Jarrin, Martin Vallée, et al.. Areas prone to slow slip events impede earthquake rupture propagation and promote afterslip. Science Advances , 2018, 4 (1), pp.eaao6596. ⟨10.1126/sciadv.aao6596⟩. ⟨hal-01727045⟩