Vanneste, K. ; Camelbeeck, T. ; Cividino, P. ; Kaufmann, O. ; Van Camp, M.

Talk presented at Colloque de l'Association Française du Génie Parasismique on 2019-09-26

Abstract: The part of the Belgian coal-mining Basin between the French border to the west and the region of Charleroi to the east suffered from several 4.0-4.5 magnitude earthquakes during the 20th century. These seismic events locally caused significant damage corresponding to EMS-98 intensity VII. In seismic hazard assessment studies currently conducted in Belgium, this earthquake activity is associated to a particular source zone called "Hainaut", which is at the origin of a high hazard in the surrounding areas. By analyzing the information on the impacts of the stronger observed earthquakes in Hainaut, we suspect that the classical ground motion prediction equations (GMPEs) used in seismic hazard assessment to evaluate ground motions at a given distance for a given earthquake magnitude do not take into account the strong observed intensity attenuation. Moreover, we discuss the possibility that this seismicity could have been induced by stopping or accelerating phases of mining activities during the course of the 20th century. For these reasons, we compared three different seismic hazard maps to evaluate the impact of using more adapted GMPEs to the context of the Hainaut seismicity and also considering that no future activity will occur as mining industry is now closed since nearly 40 years: 1. classical seismic hazard with hainaut as a source zone with classical GMPEs; 2. seismic hazard with Hainaut as a source zone, but with adapted GMPEs.

Keyword(s): Ground motion ; Hainaut ; Seismic hazard
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