Kekerengu Fault, New Zealand: Timing and Size of Late Holocene Surface Ruptures

Research Article| January 02, 2018 Kekerengu Fault, New Zealand: Timing and Size of Late Holocene Surface Ruptures T. A. Little; T. A. Little aSchool of Geography, Environment and Earth Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6040, New Zealand, timothy.little@vuw.ac.nz Search for other works by this author on: GSW Google Scholar R. Van Dissen; R. Van Dissen bActive Landscapes Group, GNS Science, P.O. Box 30368, Lower Hutt 5040, New Zealand Search for other works by this author on: GSW Google Scholar J. Kearse; J. Kearse aSchool of Geography, Environment and Earth Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6040, New Zealand, timothy.little@vuw.ac.nz Search for other works by this author on: GSW Google Scholar K. Norton; K. Norton aSchool of Geography, Environment and Earth Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6040, New Zealand, timothy.little@vuw.ac.nz Search for other works by this author on: GSW Google Scholar A. Benson; A. Benson aSchool of Geography, Environment and Earth Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6040, New Zealand, timothy.little@vuw.ac.nz Search for other works by this author on: GSW Google Scholar N. Wang N. Wang aSchool of Geography, Environment and Earth Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6040, New Zealand, timothy.little@vuw.ac.nz Search for other works by this author on: GSW Google Scholar Author and Article Information T. A. Little aSchool of Geography, Environment and Earth Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6040, New Zealand, timothy.little@vuw.ac.nz R. Van Dissen bActive Landscapes Group, GNS Science, P.O. Box 30368, Lower Hutt 5040, New Zealand J. Kearse aSchool of Geography, Environment and Earth Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6040, New Zealand, timothy.little@vuw.ac.nz K. Norton aSchool of Geography, Environment and Earth Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6040, New Zealand, timothy.little@vuw.ac.nz A. Benson aSchool of Geography, Environment and Earth Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6040, New Zealand, timothy.little@vuw.ac.nz N. Wang aSchool of Geography, Environment and Earth Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6040, New Zealand, timothy.little@vuw.ac.nz Publisher: Seismological Society of America First Online: 02 Jan 2018 Online Issn: 1943-3573 Print Issn: 0037-1106 © Seismological Society of America Bulletin of the Seismological Society of America (2018) 108 (3B): 1556–1572. https://doi.org/10.1785/0120170152 Article history First Online: 02 Jan 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation T. A. Little, R. Van Dissen, J. Kearse, K. Norton, A. Benson, N. Wang; Kekerengu Fault, New Zealand: Timing and Size of Late Holocene Surface Ruptures. Bulletin of the Seismological Society of America 2018;; 108 (3B): 1556–1572. doi: https://doi.org/10.1785/0120170152 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyBulletin of the Seismological Society of America Search Advanced Search Abstract To test models of plate motion and seismic hazard through central New Zealand, ∼10 months prior to the November 2016 Kaikōura earthquake, we excavated three trenches across the Kekerengu fault. Two of these were dextrally displaced ∼9 m in the Mw 7.8 2016 Kaikōura earthquake. We analyze 13 radiocarbon samples and document paleoearthquakes at 249–108, 528–356, and 1249–903 cal. B.P. Including the 2016 rupture, the youngest three events indicate a mean recurrence interval (RI) for the Kekerengu fault of 376±32 yrs (⁠1σ⁠). This RI is within error of that of the Hope fault; moreover, using a 9±4.5 m single‐event displacement for the Kekerengu fault, this RI implies a dextral‐slip rate of 24±12 mm/yr (⁠1σ⁠), which overlaps with the late Quaternary slip rate of the Hope fault. Our data support the hypothesis—one encoded into the New Zealand National Seismic Hazard Model—that slip on the Hope fault is transferred predominantly northward onto the Jordan–Kekerengu–Needles fault to reach within 60 km of Wellington, rather than extending east‐northeast along the offshore Hope fault.The last three paleoearthquakes on the Kekerengu fault were closely spaced in time or coeval with earthquakes on the Hope fault suggesting possible stress triggering. It is possible that this correspondence may reflect the previous occurrence of complex, multifault earthquakes that—like the 2016 earthquake—involved mutual surface rupturing of these two faults and perhaps also of the subduction interface below them. Two Holocene earthquakes on the Kekerengu fault have been closely followed by others on the Wairarapa fault, most recently in 1855. The latter two faults straddle an ∼30 km width of Cook Strait. Since A.D. 1855, they have combined to rupture >200 km in central New Zealand with unusually large surface displacements. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.