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Imaging Unknown Faults in Christchurch, New Zealand, after a M6.2 Earthquake
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 75th EAGE Conference & Exhibition incorporating SPE EUROPEC 2013, Jun 2013, cp-348-00007
- ISBN: 978-90-73834-48-4
Abstract
ity of Christchurch, New Zealand, following a devastating Mw 6.3 earthquake on February 22, 2011 that caused the loss of 185 lives. The goal of the seismic program was to map previously unknown faults in and around the city for hazard assessment and to assist in the post-earthquake recovery effort. Seismic data were collected along six 2D lines, two of which were within the Christchurch metropolitan area and four were in rural areas west of the city. Recording conditions were challenging within the city, but good quality images were obtained along all of the seismic lines, with events interpretable to a depth of approximately 1.5 km. Numerous faults were imaged along the lines and these were interpreted in two groups – older faults that showed clear offsets in deep (> 1 km) reflections and younger faults that showed displacement in shallow reflections. Some faults in the latter group were interpreted to be directly associated with hypocentres of shallow after-shocks in the region. These interpretations are now being incorporated into a risk assessment for further possible shallow earthquakes in the region.