Overview of the geologic effects of the November 14, 2016, Mw 7.8 Kaikoura, New Zealand, earthquake

Scientific Investigations Report 2017-5146
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Abstract

The November 14, 2016, Kaikoura, New Zealand, earthquake (moment magnitude [Mw] 7.8) triggered more than 10,000 landslides over an area of about 12,000 square kilometers in the northeastern part of the South Island of New Zealand. In collaboration with GNS Science (the Institute of Geological and Nuclear Science Limited), we conducted ground and helicopter reconnaissance of the affected areas and assisted in rapid hazard evaluation. The majority of the triggered landslides were shallow- to moderate-depth (1–10 meters), highly disrupted falls and slides in rock and debris from Lower Cretaceous graywacke sandstone in the Seaward Kaikoura Range. Deeper, more coherent landslides in weak Upper Cretaceous to Neogene sedimentary rock also were numerous in the gentler topography south and inland (west) of the Seaward Kaikoura Range. The principal ground-failure hazards from the earthquake were the hundreds of valley-blocking landslides, many of which impounded lakes and ponds that posed potential downstream flooding hazards. Both large and small landslides also blocked road and rail corridors in many locations, including the main north-south highway (State Highway 1), which was still closed in October 2017. As part of our investigation, we compared post-earthquake field observations to the output of models used to estimate near-real-time landslide probabilities following earthquakes. The models generally over-predicted landslide occurrence and thus need further refinement.

Suggested Citation

Jibson, R.W., Allstadt, K.E., Rengers, F.K., and Godt, J.W., 2018, Overview of the geologic effects of the November 14, 2016, Mw 7.8 Kaikoura, New Zealand, earthquake: U.S. Geological Survey Scientific Investigations Report 2017–5146, 39 p., https://doi.org/10.3133/sir20175146.

ISSN: 2328-0328 (online)

Study Area

Table of Contents

  • Acknowledgments
  • Abstract
  • Introduction
  • The 2016 Kaikoura, New Zealand, Earthquake
  • Overview of Geologic Effects of the Kaikoura Earthquake
  • Effects on People and Infrastructure
  • Comparison of Observed and Modeled Landslide Distribution
  • Summary and Conclusions
  • References Cited
  • Appendix. Field Reconnaissance Observations

Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Overview of the geologic effects of the November 14, 2016, Mw 7.8 Kaikoura, New Zealand, earthquake
Series title Scientific Investigations Report
Series number 2017-5146
DOI 10.3133/sir20175146
Year Published 2018
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Geologic Hazards Science Center
Description vii, 39 p.
Country New Zealand
City Kaikoura
Online Only (Y/N) Y