Probabilistic Tsunami Hazard Assessment for a Site in Eastern Canada

摘要

Unlike probabilistic seismic hazard analysis (PSHA), there is not a well-established methodology for probabilistic tsunami hazard analysis (PTHA). The PTHA methodology presented is similar to the widely used PSHA methodology for ground motion, and incorporates both aleatory and epistemic uncertainty in calculating the probability of exceeding runup and drawdown values produced by tsunamigenic sources. Evaluating tsunami hazard is more difficult in locations such as the eastern coastline of Canada because of low tsunami recurrence rates and few historical examples. In this study, we evaluated the hazard from local and far-field earthquake and landslide tsunamigenic sources at a site on the Bay of Fundy in New Brunswick, Canada. These sources included local faults, the Puerto Rico subduction zone, fault sources in the Azores-Gibraltar plate boundary region, and landslides on the Canadian continental slope and in the Canary Islands. Using a new PTHA methodology that is closely linked to well-established PSHA methodology combined with tide stage probability, we calculated that the return period for a wave runup exceeding the tidal range of +4 m level above mean sea level (highest astronomical tide) is approximately 14,500 years.