Abstract
The 2016 Mw 7.8 Kaikoura earthquake and consequent tsunami have been controversial because of uncertainty over whether and where the plate interface ruptured and the incapability of the proposed source models to reproduce the near-field runup of 7 m. Existing models identify a wide range of locations for the interface rupture, from on land to offshore, and fail to reproduce runup of 7 m near Kaikoura. To generate the large tsunami peak in Kaikoura tide gauge record and the observed runup height, offshore seafloor movement is necessary, but the offshore extension of the plate-interface rupture and its type, either seismic rupture or a landslide, is uncertain. Here, we propose a submarine landslide in addition to the earthquake source, with the landslide delayed 10–20 min after the earthquake rupture. The landslide volume is 4.5–5.2 km3, located within 173.7–174.3oE (longitude) and 42.6–42.15oS (latitude). Our proposed dual tsunami source successfully reproduces near-field tide gauge records as well as observed near-field runup height of 7 m. We showed that more accurate source models of earthquakes can be achieved by considering observed runup data through runup inversions in addition to waveform inversions.
Original language | English |
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Pages (from-to) | 113-121 |
Number of pages | 9 |
Journal | Ocean Engineering |
Volume | 175 |
DOIs | |
Publication status | Published - 1 Mar 2019 |
Bibliographical note
Funding Information:We used tide gauge records of GNS Science and Land Information New Zealand accessed through the IOC's website (http://www.ioc-sealevelmonitoring.org/). Ian Hamling (GNS Science) shared his source model. Satoshi Kusumoto (University of Tokyo) helped with tsunami travel time analysis. We sincerely thank two anonymous reviewers for their constructive review comments which helped us to improve this article. This research was funded by Brunel Research Initiative and Enterprise Fund 2017/18 (BUL BRIEF) at the Brunel University London to the lead author (MH). DRT publishes with the approval of the CEO, British Geological Survey.
Funding Information:
We used tide gauge records of GNS Science and Land Information New Zealand accessed through the IOC's website ( http://www.ioc-sealevelmonitoring.org/ ). Ian Hamling (GNS Science) shared his source model. Satoshi Kusumoto (University of Tokyo) helped with tsunami travel time analysis. We sincerely thank two anonymous reviewers for their constructive review comments which helped us to improve this article. This research was funded by Brunel Research Initiative and Enterprise Fund 2017/18 (BUL BRIEF) at the Brunel University London to the lead author (MH). DRT publishes with the approval of the CEO, British Geological Survey. Appendix A
Publisher Copyright:
© 2019 The Authors
Funding
We used tide gauge records of GNS Science and Land Information New Zealand accessed through the IOC's website (http://www.ioc-sealevelmonitoring.org/). Ian Hamling (GNS Science) shared his source model. Satoshi Kusumoto (University of Tokyo) helped with tsunami travel time analysis. We sincerely thank two anonymous reviewers for their constructive review comments which helped us to improve this article. This research was funded by Brunel Research Initiative and Enterprise Fund 2017/18 (BUL BRIEF) at the Brunel University London to the lead author (MH). DRT publishes with the approval of the CEO, British Geological Survey. We used tide gauge records of GNS Science and Land Information New Zealand accessed through the IOC's website ( http://www.ioc-sealevelmonitoring.org/ ). Ian Hamling (GNS Science) shared his source model. Satoshi Kusumoto (University of Tokyo) helped with tsunami travel time analysis. We sincerely thank two anonymous reviewers for their constructive review comments which helped us to improve this article. This research was funded by Brunel Research Initiative and Enterprise Fund 2017/18 (BUL BRIEF) at the Brunel University London to the lead author (MH). DRT publishes with the approval of the CEO, British Geological Survey. Appendix A
Keywords
- 2016 Kaikoura earthquake
- Dual tsunami source
- New Zealand
- Numerical simulations
- Submarine landslide
- Tsunami
ASJC Scopus subject areas
- Environmental Engineering
- Ocean Engineering