QUANTIFYING 3D DEFORMATION IN THE 14 NOVEMBER MW 7.8 KAIKOURA, NEW ZEALAND EARTHQUAKE USING A NOVEL TECHNIQUE FOR CORRELATION OF OPTICAL SATELLITE IMAGERY

The 14 November 2016 M_W 7.8 Kaikoura, New Zealand earthquake produced up to ~12 m of lateral surface displacement, and up to ~8 m of vertical surface displacement. We use a novel version of COSI-Corr optical image correlation software to capture coseismic deformation in three dimensions using high-resolution WorldView satellite imagery. This technique is capable of providing precise (< 1 m precision) measurements of both lateral and vertical displacement across large areas (100’s of km²). Because our 3D COSI-Corr results encompass both near-field (“on-fault”) and far-field (“off-fault”) deformation, they are ideal for facilitating comparison of traditional field measurements (which commonly miss far-field deformation), with more regional patterns of deformation. Understanding how on-fault field measurements reflect broader patterns of strain release in earthquakes is essential for the proper interpretation and use of geologic measurements of prehistoric fault displacements, and for understanding the controls on the 3D distribution of near-surface deformation in large earthquakes.