title: Diverse rupture processes in the 2015 Peru deep earthquake doublet.
abstract: Earthquakes in deeply subducted oceanic lithosphere can involve either brittle or dissipative ruptures. On 24 November 2015, two deep (606 and 622 km) magnitude 7.5 and 7.6 earthquakes occurred 316 s and 55 km apart. The first event (E1) was a brittle rupture with a sequence of comparable-size subevents extending unilaterally ~50 km southward with a rupture speed of ~4.5 km/s. This earthquake triggered several aftershocks to the north along with the other major event (E2), which had 40% larger seismic moment and the same duration (~20 s), but much smaller rupture area and lower rupture speed than E1, indicating a more dissipative rupture. A minor energy release ~12 s after E1 near the E2 hypocenter, possibly initiated by the S wave from E1, and a clear aftershock ~165 s after E1 also near the E2 hypocenter, suggest that E2 was likely dynamically triggered. Differences in deep earthquake rupture behavior are commonly attributed to variations in thermal state between subduction zones. However, the marked difference in rupture behavior of the nearby Peru doublet events suggests that local variations of stress state and material properties significantly contribute to diverse behavior of deep earthquakes.
authors.affiliation: Seismological Laboratory, California Institute of Technology, Pasadena, CA 91125, USA.
authors.forename: Lingling
authors.initials: L
authors.lastname: Ye
authors.affiliation: Department of Earth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, CA 95064, USA.
authors.forename: Thorne
authors.initials: T
authors.lastname: Lay
authors.affiliation: Seismological Laboratory, California Institute of Technology, Pasadena, CA 91125, USA.
authors.forename: Hiroo
authors.initials: H
authors.lastname: Kanamori
authors.affiliation: Seismological Laboratory, California Institute of Technology, Pasadena, CA 91125, USA.
authors.forename: Zhongwen
authors.initials: Z
authors.lastname: Zhan
authors.affiliation: Institut de Physique du Globe de Strasbourg, Université de Strasbourg/EOST, CNRS, Strasbourg, France.
authors.forename: Zacharie
authors.identifier: 0000-0002-8809-451X
authors.initials: Z
authors.lastname: Duputel
mesh_terms: D055866:Earthquakes / Q000266:history; D055593:Geological Phenomena; D049674:History, 21st Century; D006801:Humans; D008962:Models, Theoretical; D010568:Peru
keywords: Earthquakes; deep earthquakes; geophysics; rupture process; seismology