Segmentation in episodic tremor and slip all along Cascadia

Abstract

Research Article| October 01, 2007 Segmentation in episodic tremor and slip all along Cascadia Michael R. Brudzinski; Michael R. Brudzinski 1Department of Geology, Miami University, Oxford, Ohio 45046, USA Search for other works by this author on: GSW Google Scholar Richard M. Allen Richard M. Allen 2Seismological Laboratory, Department of Earth & Planetary Science, University of California–Berkeley, Berkeley, California 94720, USA Search for other works by this author on: GSW Google Scholar Geology (2007) 35 (10): 907–910. https://doi.org/10.1130/G23740A.1 Article history received: 07 Feb 2007 rev-recd: 09 May 2007 accepted: 17 May 2007 first online: 09 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 Michael R. Brudzinski, Richard M. Allen; Segmentation in episodic tremor and slip all along Cascadia. Geology 2007;; 35 (10): 907–910. doi: https://doi.org/10.1130/G23740A.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 The recent discovery of episodic tremor and slip (ETS) in subduction zones is based on slow slip episodes visible in global positioning system observations correlated with nonvolcanic tremor signals on seismometers. ETS occurs just inboard from a region capable of great megathrust earthquakes; however, whether there is any communication between these two processes remains unknown. In this study we use new single-station methods to compile an ETS catalog for the entire Cascadia subduction zone, offshore western North America, and compare the patterns with a variety of along-strike trends for the subducting and overriding plates. Correlated ground vibrations and strain observations are found all along the subduction zone, demonstrating that ETS is an inherent part of the subduction process. There are three broad (300–500 km), coherent zones with different recurrence intervals (14 ± 2, 19 ± 4, 10 ± 2 months), where the interval duration is inversely proportional to upper plate topography and the spatial extent correlates with geologic terranes. These zones are further divided into segments of ETS that occur at times typically offset from each other. The seven largest (100–200 km) segments appear to be located immediately landward from forearc basins interpreted as manifestations of megathrust asperities, implying that there is a spatial link between ETS and earthquake behavior. It is not yet clear if any temporal link exists, but the regional time between ETS episodes could be controlled by strength variations due to composition of geologic terranes. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.