Estimating Rupture Directions from Local Earthquake Data Using the IPO Observatory in Northern Chile

J. Folesky, J. Kummerow, G. Asch

Penerbit : Seismological Research Letters

Tahun : 2018

Local seismic broadband recordings of the Integrated Plate boundary Observatory Chile (IPOC) are used to determine rupture directions for 60 M ≥ 5:0 events in the foreshock and aftershock series of the 2014 Mw 8.1 Iquique earthquake in northern Chile. The applied method is based on accurate measurements of the P-wave coda polarization, which exhibits systematic, azimuth-dependent variations with time as the earthquake rupture propagates. We demonstrate a general consistency with observations from teleseismic backprojection studies for the main event and its largest foreshock (Mw 6.7) and aftershock (Mw 7.6). A large portion of the here analyzed events show unilateral rupture behavior, with a predominance of down-dip (east) oriented directivity. This study documents the potential of retrieving rupture directions for M ∼ 5 earthquakes from a high-quality local seismic monitoring system

Pengarang