Paleomagnetism-based limits on earthquake magnitudes in northwestern metropolitan Los Angeles, California, USA

Research Article| May 01, 2005 Paleomagnetism-based limits on earthquake magnitudes in northwestern metropolitan Los Angeles, California, USA Shaul Levi; Shaul Levi 1College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, Oregon 97331-5503, USA Search for other works by this author on: GSW Google Scholar John Nabelek; John Nabelek 1College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, Oregon 97331-5503, USA Search for other works by this author on: GSW Google Scholar Robert S. Yeats Robert S. Yeats 2Department of Geosciences, Oregon State University, Corvallis, Oregon 97331, USA Search for other works by this author on: GSW Google Scholar Geology (2005) 33 (5): 401–404. https://doi.org/10.1130/G21190.1 Article history received: 13 Sep 2004 rev-recd: 03 Jan 2005 accepted: 17 Jan 2005 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Shaul Levi, John Nabelek, Robert S. Yeats; Paleomagnetism-based limits on earthquake magnitudes in northwestern metropolitan Los Angeles, California, USA. Geology 2005;; 33 (5): 401–404. doi: https://doi.org/10.1130/G21190.1 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 SocietyGeology Search Advanced Search Abstract We have used paleomagnetism to estimate the maximum moment magnitude (Mw) of earthquakes in the east Ventura Basin and San Fernando Valley, in metropolitan Los Angeles. Magnetic declinations show differential rotation between crustal blocks with linear dimensions of 10–20 km, similar to the thickness of the seismogenic layer. The maximum magnitude of an earthquake based on blocks of this size is Mw = 6.8, comparable to the 1971 San Fernando and 1994 Northridge earthquakes and consistent with paleoseismic trenching and surface ruptures of the 1971 earthquake. The paleomagnetic results suggest that the blocks have retained their configuration while moving relative to each other for the past ∼0.8 m.y. Therefore, it is unlikely that in this area multiple blocks combined to trigger much larger shocks during this period, in contrast to adjacent regions where events with Mw > 7 have been postulated on the basis of paleoseismic excavations. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.