Highly variable coastal deformation in the 2016 MW7.8 Kaikōura earthquake reflects rupture complexity along a transpressional plate boundary.
- Author
- Clark, K.J., Nissen, E.K., Howarth, J.D., Hamling, I.J., Mountjoy, J.J., Ries, W.F., Jones, K., Goldstien, S., Cochran, U.A., Villamor, P., Hreinsdóttir, S., Litchfield, N.J., Mueller, C., Berryman, K.R., Strong, D. T.
- Year
- 2017
- Journal / Source
- Earth and Planetary Science Letters
- Number
- 474
- Pages
- 334-344
- Summary
- Coseismic coastal deformation is often used to understand slip on offshore faults in large earthquakes but in the 2016 MW7.8 Kaikoura ¯ earthquake multiple faults ruptured across and sub-parallel to the coastline. Along ∼110 km of coastline, a rich dataset of coastal deformation comprising airborne lidar differencing, field surveying and satellite geodesy reveals highly variable vertical displacements, ranging from −2.5 to 6.5 m. These inform a refined slip model for the Kaikoura ¯ earthquake which incorporates changes to the slip on offshore faults and inclusion of an offshore reverse crustal fault that accounts for broad, low-amplitude uplift centered on Kaikoura ¯ Peninsula. The exceptional detail afforded by differential lidar and the high variability in coastal deformation combine to form the highest-resolution and most complex record of coseismic coastal deformation yet documented. This should prompt reassessment of coastal paleoseismic records that may not have considered multi-fault ruptures and high complexity deformation fields.