Paleoearthquakes at the junction of the Tokomaru and Northern Ōhāriu faults, implications for fault interactions in the southern North Island, New Zealand

• DOI: 10.1080/00288306.2023.2263403
• Publication Date: 2023-10-09T22:53:40Z
• Authors: Genevieve L. Coffey; Robert M. Langridge; Nicola J. Litchfield; Russ J. Van Dissen; Kate J. Clark

ABSTRACTThe Tokomaru Fault extends along the west side of southern North Island New Zealand. Given fault’s proximity to major and expanding population centres, new work was undertaken understand its contribution seismic hazard in Wellington-Levin corridor. Two paleoseismic trenches excavated across end Fault, close junction with Northern Ōhāriu show that it are more active than previously thought. Ages two youngest events on 93–220 1179–1254 cal yr BP, result a recurrence interval 470–2300 years. These ages agree timing some Wellington Fault. This suggests Tokomaru, Ōhāriu, faults may have ruptured together past, triggered earthquakes each other, or host slip is by larger nearby earthquakes. The results this illustrate importance fault interactions even if here do not rupture together, they likely play key role influencing earthquake behaviour other.KEYWORDS: FaultTokomaru FaultHorowhenuaKāpiti Coastearthquakepaleoseismic trenchingrecurrence intervalfault AcknowledgementsWe would like thank Daniel Rebecca Kilsby-Halliday, Blair Anna Robinson for access allowing us excavate their land. as part It’s Our programme we grateful Toka Tū Ake EQC, Regional Management Group City Council funding work. project supported Zealand Ministry Business, Innovation Employment (MBIE) through Hazards Risk (Strategic Science Investment Fund, contract C05X1702). We also thank, Andy Dodd his archaeological assessment, Danielle Willis help UAV survey at Makahika, Dr Ningsheng Wang processing OSL samples, team Rafter Laboratory GNS analysis radiocarbon samples. Pilar Villamor Dougal Townsend useful feedback manuscript. anonymous reviewer Jack Williams edits comments manuscript during review process.Data availability statementThe data supporting findings study available within article supplementary materials, which been uploaded Figshare (dx.doi.org/10.6084/m9.figshare.6025748).Disclosure statementNo potential conflict interest reported author(s).Additional informationFundingThis “Its Fault”.