Late Quaternary paleoseismic history and surface rupture characteristics of the eastern Awatere strike-slip fault, New Zealand

Research Article| August 01, 2001 Late Quaternary paleoseismic history and surface rupture characteristics of the eastern Awatere strike-slip fault, New Zealand A.M. Benson; A.M. Benson 1School of Earth Sciences, Victoria University, P.O. Box 600, Wellington, New Zealand Search for other works by this author on: GSW Google Scholar T.A. Little; T.A. Little 1School of Earth Sciences, Victoria University, P.O. Box 600, Wellington, New Zealand Search for other works by this author on: GSW Google Scholar R.J. Van Dissen; R.J. Van Dissen 2Institute of Geological and Nuclear Sciences, P.O. Box 30368, Lower Hutt, New Zealand Search for other works by this author on: GSW Google Scholar N. Hill; N. Hill 3School of Earth Sciences, Victoria University, P.O. Box 600, Wellington, New Zealand Search for other works by this author on: GSW Google Scholar D.B. Townsend D.B. Townsend 3School of Earth Sciences, Victoria University, P.O. Box 600, Wellington, New Zealand Search for other works by this author on: GSW Google Scholar Author and Article Information A.M. Benson 1School of Earth Sciences, Victoria University, P.O. Box 600, Wellington, New Zealand T.A. Little 1School of Earth Sciences, Victoria University, P.O. Box 600, Wellington, New Zealand R.J. Van Dissen 2Institute of Geological and Nuclear Sciences, P.O. Box 30368, Lower Hutt, New Zealand N. Hill 3School of Earth Sciences, Victoria University, P.O. Box 600, Wellington, New Zealand D.B. Townsend 3School of Earth Sciences, Victoria University, P.O. Box 600, Wellington, New Zealand Publisher: Geological Society of America Received: 18 Oct 1999 Revision Received: 31 May 2000 Accepted: 10 Jul 2000 First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (2001) 113 (8): 1079–1091. https://doi.org/10.1130/0016-7606(2001)113<1079:LQPHAS>2.0.CO;2 Article history Received: 18 Oct 1999 Revision Received: 31 May 2000 Accepted: 10 Jul 2000 First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation A.M. Benson, T.A. Little, R.J. Van Dissen, N. Hill, D.B. Townsend; Late Quaternary paleoseismic history and surface rupture characteristics of the eastern Awatere strike-slip fault, New Zealand. GSA Bulletin 2001;; 113 (8): 1079–1091. doi: https://doi.org/10.1130/0016-7606(2001)113<1079:LQPHAS>2.0.CO;2 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 SocietyGSA Bulletin Search Advanced Search Abstract The recurrence and magnitude of paleo- earthquakes on the eastern section of the dextral strike-slip Awatere fault (>105 km long) are determined from stratigraphic evidence in a fault trench and measurement of fault-displaced geomorphic features. We identify at least six ground-rupturing events younger than 8330–8610 yr, the youngest being a historically recorded Mw ∼ 7.5 event in A.D. 1848 that ruptured the entire eastern section. The maximum mean recurrence interval is ∼1.4 k.y., although repeat intervals range from 605 ± 235 to 2500 ± 600 yr. The smallest fault offsets on the easternmost 27 km of the onshore part of the fault indicate a mean strike-slip displacement of 4.9 m during the 1848 event. The second-smallest offsets are approximately double the smallest displacements, suggesting that the last two events were ruptures of comparable dimensions (>105 km) and magnitude. Because the Awatere fault terminates <20 km northeast of the study area, the penultimate rupture probably extended inland, perhaps rupturing the entire eastern section. Further evidence of characteristic earthquake behavior is preserved in the fault trench, where a regular event subsidence of ∼50 cm per event is indicated. During the last two events a slip maximum of 7 ± 1 m occurred on a 5.5-km-long fault subsection consisting of adjacent restoring and releasing fault bends. These bends define a 1-km-wide side step in the fault that, although of short wavelength, apparently strongly influences the amount of coseismic slip and moment release. New data on the age of late Quaternary alluvial surfaces in the Awatere Valley, when combined with observed horizontal displacements, indicate that strike slip has accrued on the Awatere fault at a constant rate of 6 mm/yr for at least the past 20 k.y. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.