hide
Free keywords:
-
Abstract:
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.
