Broadband Seismological Observations of Aftershocks of the September 16, 2015 Mw 8.3 Illapel Earthquake, Chile

University Of Florida, Gainesville FL

Investigators

Abstract

The PIs proposed to deploy 20 broadband seismic stations for one year in the rupture zone of the Mw 8.3 Illapel, Chile earthquake. The instruments will enable locating and characterizing thousands of aftershocks from the large earthquake. This data can be used to better understand the Nazca-South America plate interface as well as the processes behind the megathrust rupture and postseismic activity. The ability to capture the high seismicity rate immediately after the earthquake will enable both a finer picture of the subduction structure, as well improve our understanding of seismic hazard in the region. The vigorous aftershock series now occurring in the wake of the 2015 Illapel, Chile Earthquake provides a rare opportunity to study syuduction zone segmentation, as delineated by adjacent megathrust ruptures. While the aftershock seismicity rate is high, researchers can take advantage to illuminate the Nazca and South American interplate interface, looking for evidence of differences in slip regime as discernible from aftershock locations and characteristics such as focal mechanisms, slip speed and spectral and attenuation characteristics. The deployment will produce a high quality, open access data set that will capture time-limited phenomena.