2010 Maule earthquake slip correlates with pre-seismic locking of Andean subduction zone

Abstract

The magnitude-8.8 Maule (Chile) earthquake of 27 February 2010 ruptured a segment of the Andean subduction zone megathrust that has been suspected to be of high seismic potential. It is the largest earthquake to rupture a mature seismic gap in a subduction zone that has been monitored with a dense space-geodetic network before the event. This provides an image of the pre-seismically locked state of the plate interface of unprecedentedly high resolution, allowing for an assessment of the spatial correlation of interseismic locking with coseismic slip. Pre-seismic locking might be used to anticipate future ruptures in many seismic gaps, given the fundamental assumption that locking and slip are similar. This hypothesis, however, could not be tested without the occurrence of the first gap-filling earthquake. Here we show evidence that the 2010 Maule earthquake slip distribution correlates closely with the patchwork of interseismic locking distribution as derived by inversion of global positioning system (GPS) observations during the previous decade. The earthquake nucleated in a region of high locking gradient and released most of the stresses accumulated in the area since the last major event in 1835. Two regions of high seismic slip (asperities) appeared to be nearly fully locked before the earthquake. Between these asperities, the rupture bridged a zone that was creeping interseismically with consistently low coseismic slip. The rupture stopped in areas that were highly locked before the earthquake but where pre-stress had been significantly reduced by overlapping twentieth-century earthquakes. Our work suggests that coseismic slip heterogeneity at the scale of single asperities should indicate the seismic potential of future great earthquakes, which thus might be anticipated by geodetic observations.

Scenario Source Models and Strong Ground Motion for Future Mega‐earthquakes: Application to Lima, Central Peru

“…Some studies of the 2010 Maule earthquake support this hypothesis (Moreno et al, 2010;Pulido et al, 2011), even though the debate is still active as other studies indicate a limited overlap between seismic gap and coseismic slip (Lorito et al, 2011). A comparison of several source models for the Maule earthquake show, however, that there is a large uncertainty on the location of regions of large slip (i.e., Delouis et al, Figure 10.…”

“…In recent years, the development of Global Positioning System (GPS) and satellite radar interferometry make it possible to measure the strain buildup associated with plate coupling in many earthquakeprone regions around the world (Chlieh et al, 2004(Chlieh et al, , 2011Béjar-Pizarro et al, 2013). Recent studies have suggested that subducting plates are either locked or creeping aseismically, and that a patchwork of locked or coupled regions during the interseismic period may be related with asperities of earthquakes (Konca et al, 2008;Moreno et al, 2010;Perfettini et al, 2010;Loveless and Meade, 2011). In this study, we propose a methodology to characterize source models of future megathrust earthquakes based on the spatial distribution of interseismic coupling (ISC) of subduction zones as well as information of historical earthquakes.…”

An earthquake gap south of Istanbul

“…Barriers are resistant to failure and do not show microseismicity during the inter-seismic period. When a barrier finally ruptures, surrounding areas can catch up with plate motions, leading to activation of sub-faults and segments 27 region of high locking gradient and ended up releasing most of the stress accumulated along its fault plane since the last major event 28 . We suggest that such a scenario may apply to the Princes Island and Marmara segments of the NAFZ.…”

Comparison of postseismic afterslip models with aftershock seismicity for three subduction-zone earthquakes: Nias 2005, Maule 2010 and Tohoku 2011

“…C: Vertical displacements. ), green: Moreno et al (2012), orange: Delouis et al (2010, Bouguer anomaly and interseismic coupling distribution from Moreno et al (2010). Location of the profile is shown in Fig.…”