Seismic Moments of the Larger Earthquakes of the Southern California Region

Research Article| August 01, 1975 Seismic Moments of the Larger Earthquakes of the Southern California Region THOMAS C. HANKS; THOMAS C. HANKS 1Seismological Laboratory and Earthquake Engineering Research Laboratory, California Institute of Technology, Pasadena, California 91125 Search for other works by this author on: GSW Google Scholar JAMES A. HILEMAN; JAMES A. HILEMAN 2Seismological Laboratory, California Institute of Technology, Pasadena, California 91125 Search for other works by this author on: GSW Google Scholar WAYNE THATCHER WAYNE THATCHER 3National Center for Earthquake Research, U.S. Geological Survey, 345 Middlefield Road, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar Author and Article Information THOMAS C. HANKS 1Seismological Laboratory and Earthquake Engineering Research Laboratory, California Institute of Technology, Pasadena, California 91125 JAMES A. HILEMAN 2Seismological Laboratory, California Institute of Technology, Pasadena, California 91125 WAYNE THATCHER 3National Center for Earthquake Research, U.S. Geological Survey, 345 Middlefield Road, Menlo Park, California 94025 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1975) 86 (8): 1131–1139. https://doi.org/10.1130/0016-7606(1975)862.0.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation THOMAS C. HANKS, JAMES A. HILEMAN, WAYNE THATCHER; Seismic Moments of the Larger Earthquakes of the Southern California Region. GSA Bulletin 1975;; 86 (8): 1131–1139. doi: https://doi.org/10.1130/0016-7606(1975)862.0.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 seismic moment (M0) of an earthquake is a more consistent and more physical measure of source strength than magnitude (M) or strain release (see pdf for formula), and this measure of source strength is determined for 47 of the larger earthquakes occurring in the Southern California region since 1857. Most of the seismic moments are obtained by conventional seismological means, but a relationship between M0 and the areal distribution of Intensity VI (AVI) is developed and scaled to estimate M0 when intensity data are available but instrumental data are not. This relationship is log M0 = 1.97 log AVI − 2.55. For the region as a whole, earthquakes at the threshold of M0 ≥ 1025, ≥1026, and ≥1027 dyne-cm have occurred once every 3, 8, and 25 yr, respectively. The spatial occurrence of the five largest earthquakes (M0 ≥ 1 × 1027 dyne-cm) is not limited to a particular geologic province, mode of tectonic accommodation, or geographic locality. It is unlikely that this data set can reliably predict long-term spatial and temporal patterns of the M0 ≥ 1025 dyne-cm seismicity of the Southern California region. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.