ASSESSMENT OF A LARGE EARTHQUAKE RISKIN THE ZONE OF MAIN SAYAN FAULT USING GPS GEODESY AND PALEOSEISMOLOGY
V.A. San'kov, A.V. Chipizubov, A.V. Lukhnev, O.P. Smekalin,A.I. Miroshnichenko, E. Calais*, and J. Déverchère**
Institute of the Earth's Crust, Siberian Branch of the RAS, 128 ul. Lermontova, Irkutsk, 664 033, Russia
* Purdue University, West Lafayette, IN 47907-1397, USA
** Universitéde Bretagne Occidentale (UBO), Institut Universitaire Européen de la Mer (IUEM),Technopôle Brest-Iroise, Place Nicolas Copernic, F-29280, Plouzané, France
Keywords: Faults, GPS measurements, paleoseismology, slip rate, earthquake, seismic risk
Pages: 1317-1324
Subsection: GEOPHYSICS
Abstract
GPS and paleoseismological studies of Holocene and recent slip rates in the zone of the Main Sayan Fault show that the fault is currently locked, and the accumulated stress may release in a large earthquake. The southeastern flank of the fault generated at least five large earthquakes for the past 10 kyr. For the time elapsed since the ultimate event, the fault has accumulated pending displacement of 1.4-3.1 m, given its 3.1 mm/yr average slip, which can be accommodated in an M = 7.1-7.5 earthquake. Thus the densely populated industrial areas around the southeastern fault flank in the southern Baikal region are exposed to high seismic risk.
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