RAPID: Testing the erosion signature of coseismic landslides using cosmogenic catchment wide erosion rates - a case study of the 2016 Kaikoura Earthquake, New Zealand

University Of Washington, Seattle WA

Investigators

Abstract

The 14 November 2016 M 7.8 Kaikoura Earthquake in New Zealand triggered thousands of landslides, blocked major highways and destroyed rail system infrastructure, leaving 1000 residents and tourists trapped in the seaside town of Kaikoura. This event and the investigator's previous research and sampling in the region presents a rare opportunity to study erosion associated with widespread landslides that occur at the same time as major earthquakes. This Rapid Response Research (RAPID) project will examine the erosion associated with these landslides using modern geological techniques. It will enhance international collaboration between the US and New Zealand and involve three graduate students in the scientific research process. The project is led by an early career female investigator. This project will address the following questions of relevance to the geomorphology and geochronology communities: 1) What effect does coseismic landsliding have on detrital cosmogenic radionuclide (CRN) derived basin wide erosion rates? and 2) What is the contribution of periodic but widespread coseismic landslides to erosional mass flux in tectonically active mountain belts such as the Kaikoura Ranges? The principal investigator and her team will address these questions by doing repeat detrital 10Be CRN measurements in six drainages shaken by the earthquake. These samples will be used to examine basin-wide erosion rates following extensive coseismic landsliding. Landsliding is predicted to complicate detrital CRN measurements of basin wide erosion rates. This study will circumvent this complication by constraining erosion rates before (with previously collected samples) and directly following a large earthquake (to be sampled this January 2017).