The 4 August 2004, Lake Ontario, Earthquake

Abstract

Other| January 01, 2006 The 4 August 2004, Lake Ontario, Earthquake Won-Young Kim; Won-Young Kim Lamont-Doherty Earth Observatory of Columbia University Palisades, NY 10964 wykim@ldeo.columbia.edu (W.-Y. K.) Search for other works by this author on: GSW Google Scholar Savka Dineva; Savka Dineva Department of Earth Sciences, University of Western Ontario 1151 Richmond Street London, Ontario N6A 5B7, Canada (S. D., S. M., D. E.) Search for other works by this author on: GSW Google Scholar Shutian Ma; Shutian Ma Department of Earth Sciences, University of Western Ontario 1151 Richmond Street London, Ontario N6A 5B7, Canada (S. D., S. M., D. E.) Search for other works by this author on: GSW Google Scholar David Eaton David Eaton Department of Earth Sciences, University of Western Ontario 1151 Richmond Street London, Ontario N6A 5B7, Canada (S. D., S. M., D. E.) Search for other works by this author on: GSW Google Scholar Author and Article Information Won-Young Kim Lamont-Doherty Earth Observatory of Columbia University Palisades, NY 10964 wykim@ldeo.columbia.edu (W.-Y. K.) Savka Dineva Department of Earth Sciences, University of Western Ontario 1151 Richmond Street London, Ontario N6A 5B7, Canada (S. D., S. M., D. E.) Shutian Ma Department of Earth Sciences, University of Western Ontario 1151 Richmond Street London, Ontario N6A 5B7, Canada (S. D., S. M., D. E.) David Eaton Department of Earth Sciences, University of Western Ontario 1151 Richmond Street London, Ontario N6A 5B7, Canada (S. D., S. M., D. E.) Publisher: Seismological Society of America First Online: 09 Mar 2017 Online ISSN: 1938-2057 Print ISSN: 0895-0695 © 2006 by the Seismological Society of America Seismological Research Letters (2006) 77 (1): 65–73. https://doi.org/10.1785/gssrl.77.1.65 Article history 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 Won-Young Kim, Savka Dineva, Shutian Ma, David Eaton; The 4 August 2004, Lake Ontario, Earthquake. Seismological Research Letters 2006;; 77 (1): 65–73. doi: https://doi.org/10.1785/gssrl.77.1.65 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 SocietySeismological Research Letters Search Advanced Search Abstract A Mw 3.1 earthquake occurred in Lake Ontario along the United States–Canada border, about 30 km south from Port Hope, Ontario, Canada, on 4 August 2004. Despite its small size, the shock was very well recorded by broadband seismographic stations deployed in recent years in Ontario, Canada, and in New York State. More than 40 broadband stations at local and regional ranges provided high-quality digital data. Waveform data analysis constrained the source at a depth of 4 (±2) km, which places the shock in the shallow Precambrian basement beneath Paleozoic platform deposits. Th e source mechanism from the regional waveform inversion for the double-couple moment tensor is predominantly strike-slip faulting. A NS striking (8°) nodal plane dipping to the east (dip = 59°) is the likely fault plane which represents right-lateral strike-slip motion. Th e subhorizontal P-axis orientation (trend = 234° and plunge = 12°) is consistent with the maximum horizontal compressional stress (SHmax) direction in eastern North America. Although the 4 August 2004 event is a small shock and has the seismic moment of M0 = 4.45 (±2.30) × 1013 Nm, it is the largest instrumentally recorded earthquake that has occurred in Lake Ontario. This and other significant earthquakes in the region suggest a broad-scale strike-slip faulting stress regime with a shallow seismogenic layer in the Erie–Ontario Lowlands region. The shallow focal depths of earthquakes in the region increase the risk of higher ground shaking compared to other seismic zones in northeastern North America with a deeper seismogenic layer. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.