Landslides triggered by the 14 November 2016 Mw 7.8 Kaikōura Earthquake, New Zealand

Bulletin of the Seismological Society of America
By: , and 

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Abstract

The 14 November 2016 MwMw 7.8 Kaikōura earthquake generated more than 10,000 landslides over a total area of about 10,000  km210,000  km2, with the majority concentrated in a smaller area of about 3600  km23600  km2. The largest landslide triggered by the earthquake had an approximate volume of 20(±2)  Mm320(±2)  M m3, with a runout distance of about 2.7 km, forming a dam on the Hapuku River. In this article, we present version 1.0 of the landslide inventory we have created for this event. We use the inventory presented in this article to identify and discuss some of the controls on the spatial distribution of landslides triggered by the Kaikōura earthquake. Our main findings are (1) the number of medium to large landslides (source area 10,000  m2≥10,000  m2) triggered by the Kaikōura earthquake is smaller than for similar‐sized landslides triggered by similar magnitude earthquakes in New Zealand; (2) seven of the largest eight landslides (from 5 to 20  Mm320  M m3) occurred on faults that ruptured to the surface during the earthquake; (3) the average landslide density within 200 m of a mapped surface fault rupture is three times that at a distance of 2500 m or more from a mapped surface fault rupture; (4) the “distance to fault” predictor variable, when used as a proxy for ground‐motion intensity, and when combined with slope angle, geology, and elevation variables, has more power in predicting landslide probability than the modeled peak ground acceleration or peak ground velocity; and (5) for the same slope angles, the coastal slopes have landslide point densities that are an order of magnitude greater than those in similar materials on the inland slopes, but their source areas are significantly smaller.

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Publication type Article
Publication Subtype Journal Article
Title Landslides triggered by the 14 November 2016 Mw 7.8 Kaikōura Earthquake, New Zealand
Series title Bulletin of the Seismological Society of America
DOI 10.1785/0120170305
Volume 108
Issue 3B
Year Published 2018
Language English
Publisher Seismological Society of America
Contributing office(s) Geologic Hazards Science Center
Description 19 p.
First page 1630
Last page 1648
Country New Zealand
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