25,000 Years long seismic cycle in a slow deforming continental region of Mongolia.

Autor: Bollinger L; CEA, DAM, DIF, Arpajon, France. Laurent.bollinger@cea.fr., Klinger Y; Institut de Physique du Globe de Paris, CNRS, Université de Paris, Paris, France., Forman SL; Geoluminescence Dating Research Laboratory, Department of Geosciences, Baylor University, One Bear Place, Waco, TX, 76798, USA., Chimed O; Institute of Astronomy and Geophysics, Ulaanbaatar, Mongolia., Bayasgalan A; Mongolian University of Science and Technology, Ulaanbaatar, Mongolia., Munkhuu U; Institute of Astronomy and Geophysics, Ulaanbaatar, Mongolia., Davaasuren G; Institute of Astronomy and Geophysics, Ulaanbaatar, Mongolia., Dolgorsuren T; Institute of Astronomy and Geophysics, Ulaanbaatar, Mongolia., Enkhee B; Institute of Astronomy and Geophysics, Ulaanbaatar, Mongolia., Sodnomsambuu D; Institute of Astronomy and Geophysics, Ulaanbaatar, Mongolia.
Jazyk: angličtina
Zdroj: Scientific reports [Sci Rep] 2021 Sep 08; Vol. 11 (1), pp. 17855. Date of Electronic Publication: 2021 Sep 08.
DOI: 10.1038/s41598-021-97167-w
Abstrakt: The spatial distribution of large earthquakes in slowly deforming continental regions (SDCR) is poorly documented and, thus, has often been deemed to be random. Unlike in high strain regions, where seismic activity concentrates along major active faults, earthquakes in SDCR may seem to occur more erratically in space and time. This questions classical fault behavior models, posing paramount issues for seismic hazard assessment. Here, we investigate the M7, 1967, Mogod earthquake in Mongolia, a region recognized as a SDCR. Despite the absence of visible cumulative deformation at the ground surface, we found evidence for at least 3 surface rupturing earthquakes during the last 50,000 years, associated with a slip-rate of 0.06 ± 0.01 mm/year. These results show that in SDCR, like in faster deforming regions, deformation localizes on specific structures. However, the excessive length of return time for large earthquakes along these structures makes it more difficult to recognize earthquake series, and could conversely lead to the misconception that in SDCR earthquakes would be randomly located. Thus, our result emphasizes the need for systematic appraisal of the potential seismogenic structures in SDCR in order to lower the uncertainties associated with the seismogenic sources in seismic hazard models.
(© 2021. The Author(s).)
Databáze: MEDLINE
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