Seismic Response of Soft Deposits due to Landslide: The Mission Peak, California, Landslide

Abstract

Research Article| September 25, 2017 Seismic Response of Soft Deposits due to Landslide: The Mission Peak, California, Landslide Stephen Hartzell; Stephen Hartzell aU.S. Geological Survey, Denver Federal Center, Box 25046, MS 966, Denver, Colorado 80225, shartzell@usgs.gov Search for other works by this author on: GSW Google Scholar Alena L. Leeds; Alena L. Leeds aU.S. Geological Survey, Denver Federal Center, Box 25046, MS 966, Denver, Colorado 80225, shartzell@usgs.gov Search for other works by this author on: GSW Google Scholar Randall W. Jibson Randall W. Jibson aU.S. Geological Survey, Denver Federal Center, Box 25046, MS 966, Denver, Colorado 80225, shartzell@usgs.gov Search for other works by this author on: GSW Google Scholar Author and Article Information Stephen Hartzell aU.S. Geological Survey, Denver Federal Center, Box 25046, MS 966, Denver, Colorado 80225, shartzell@usgs.gov Alena L. Leeds aU.S. Geological Survey, Denver Federal Center, Box 25046, MS 966, Denver, Colorado 80225, shartzell@usgs.gov Randall W. Jibson aU.S. Geological Survey, Denver Federal Center, Box 25046, MS 966, Denver, Colorado 80225, shartzell@usgs.gov Publisher: Seismological Society of America First Online: 27 Sep 2017 Online Issn: 1943-3573 Print Issn: 0037-1106 Bulletin of the Seismological Society of America (2017) 107 (5): 2008–2020. https://doi.org/10.1785/0120170033 Article history First Online: 27 Sep 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Stephen Hartzell, Alena L. Leeds, Randall W. Jibson; Seismic Response of Soft Deposits due to Landslide: The Mission Peak, California, Landslide. Bulletin of the Seismological Society of America 2017;; 107 (5): 2008–2020. doi: https://doi.org/10.1785/0120170033 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 The seismic response of active and intermittently active landslides is an important issue to resolve to determine if such landslides present an elevated hazard in future earthquakes. To study the response of landslide deposits, seismographs were placed on the Mission Peak landslide in the eastern San Francisco Bay region for a period of one year. Numerous local and near‐regional earthquakes were recorded that reveal a complexity of seismic response phenomena using the horizontal‐to‐vertical spectral ratio method. At lower frequencies, a clear spectral peak is observed at 0.5 Hz common to all four stations in the array and is attributed to a surface topographic effect. At higher frequencies, other spectral peaks occur that are interpreted in terms of local deposits and structures. Site amplification from the standard reference site method shows the minimum amplification with a factor of 2, comparing a site on and off the landslide. A site located on relatively homogeneous deposits of loose soils shows a clear spectral peak associated with the thickness of the deposit. Another site on a talus‐filled graben near the headscarp shows possible 2D or 3D effects from subsurface topography or scattering within and between buried sandstone blocks. A third site on a massive partially detached block below the crown of the headscarp shows indications of resonance caused by the reverberation of shear waves within the block. The varied seismic response of different parts of this complex landslide is consistent with other studies which found that, although landslide response is commonly enhanced in the downslope direction of landslide movement, such a response does not occur uniformly or consistently. When it does occur, enhanced site response parallel to the direction of landslide movement would contribute to landslide reactivation during significant earthquakes. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.