Late Holocene earthquakes on the Toe Jam Hill fault, Seattle fault zone, Bainbridge Island, Washington

Abstract

Research Article| November 01, 2003 Late Holocene earthquakes on the Toe Jam Hill fault, Seattle fault zone, Bainbridge Island, Washington Alan R. Nelson; Alan R. Nelson 1Geologic Hazards Team, U.S. Geological Survey, MS 966, P.O. Box 25046, Denver, Colorado 80225, USA Search for other works by this author on: GSW Google Scholar Samuel Y. Johnson; Samuel Y. Johnson 1Geologic Hazards Team, U.S. Geological Survey, MS 966, P.O. Box 25046, Denver, Colorado 80225, USA Search for other works by this author on: GSW Google Scholar Harvey M. Kelsey; Harvey M. Kelsey 2Department of Geology, Humboldt State University, Arcata, California 95521, USA Search for other works by this author on: GSW Google Scholar Ray E. Wells; Ray E. Wells 3Western Regional Geology Team, U.S. Geological Survey, MS 975, 345 Middlefield Road, Menlo Park, California 94025, USA Search for other works by this author on: GSW Google Scholar Brian L. Sherrod; Brian L. Sherrod 4U.S. Geological Survey at Department of Earth and Space Sciences, Box 351310, University of Washington, Seattle, Washington 98195, USA Search for other works by this author on: GSW Google Scholar Silvio K. Pezzopane; Silvio K. Pezzopane 5Water Resources Division, U.S. Geological Survey, MS 421, P.O. Box 25046, Denver, Colorado 80225, USA Search for other works by this author on: GSW Google Scholar Lee-Ann Bradley; Lee-Ann Bradley 6Geologic Hazards Team, U.S. Geological Survey, MS 966, P.O. Box 25046, Denver, Colorado 80225, USA Search for other works by this author on: GSW Google Scholar Rich D. Koehler, III; Rich D. Koehler, III 7William Lettis and Associates, Inc., 999 Andersen Drive, Suite 120, San Rafael, California 94901, USA Search for other works by this author on: GSW Google Scholar Robert C. Bucknam Robert C. Bucknam 8Geologic Hazards Team, U.S. Geological Survey, MS 966, P.O. Box 25046, Denver, Colorado 80225, USA Search for other works by this author on: GSW Google Scholar GSA Bulletin (2003) 115 (11): 1388–1403. https://doi.org/10.1130/B25262.1 Article history received: 20 Sep 2002 rev-recd: 27 May 2003 accepted: 10 Jun 2003 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Alan R. Nelson, Samuel Y. Johnson, Harvey M. Kelsey, Ray E. Wells, Brian L. Sherrod, Silvio K. Pezzopane, Lee-Ann Bradley, Rich D. Koehler, Robert C. Bucknam; Late Holocene earthquakes on the Toe Jam Hill fault, Seattle fault zone, Bainbridge Island, Washington. GSA Bulletin 2003;; 115 (11): 1388–1403. doi: https://doi.org/10.1130/B25262.1 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 Five trenches across a Holocene fault scarp yield the first radiocarbon-measured earthquake recurrence intervals for a crustal fault in western Washington. The scarp, the first to be revealed by laser imagery, marks the Toe Jam Hill fault, a north-dipping backthrust to the Seattle fault. Folded and faulted strata, liquefaction features, and forest soil A horizons buried by hanging-wall-collapse colluvium record three, or possibly four, earthquakes between 2500 and 1000 yr ago. The most recent earthquake is probably the 1050–1020 cal. (calibrated) yr B.P. (A.D. 900–930) earthquake that raised marine terraces and triggered a tsunami in Puget Sound. Vertical deformation estimated from stratigraphic and surface offsets at trench sites suggests late Holocene earthquake magnitudes near M7, corresponding to surface ruptures >36 km long. Deformation features recording poorly understood latest Pleistocene earthquakes suggest that they were smaller than late Holocene earthquakes. Postglacial earthquake recurrence intervals based on 97 radiocarbon ages, most on detrital charcoal, range from ∼12,000 yr to as little as a century or less; corresponding fault-slip rates are 0.2 mm/yr for the past 16,000 yr and 2 mm/yr for the past 2500 yr. Because the Toe Jam Hill fault is a backthrust to the Seattle fault, it may not have ruptured during every earthquake on the Seattle fault. But the earthquake history of the Toe Jam Hill fault is at least a partial proxy for the history of the rest of the Seattle fault zone. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.