Studies of Seismogenesis and Plate Boundary Structure on Canada's West Coast

板块边界断层危及加拿大西海岸沿着300多万人和社会基础设施。最大的地震危险来自卡斯卡迪亚俯冲巨型逆冲断层，该逆冲断层从加州北方延伸到北方温哥华岛，距离海岸线以西约150 km。这个板块边界经历了平均间隔约550年的M=9+地震，能够产生海啸和地面震动，与日本（2011年）和印度尼西亚（2004年）最近的大地震相当。第二个值得关注的板块边界是夏洛特女王断层，该断层沿着海达湾海岸延伸到温哥华岛北部。1949年，该断层引发了加拿大历史上最大的地震（M=8.1）。2012年10月27日，海达·冈底斯发生7.8级地震，引发了一场小型海啸，并突出了莫尔斯比岛下方存在一个额外的、向东北倾斜的主要逆冲断层。

Plate boundary faults endanger over 3 million people and societal infrastructure along Canada's west coast. The greatest seismic hazard arises from the Cascadia Subduction Megathrust that extends from northern California to northern Vancouver Island, approximately ~150 km west of the coastline. This plate boundary has experienced M=9+ earthquakes at intervals averaging ~550 years and is capable of generating tsunamis and ground shaking comparable to recent great earthquakes in Japan (2011) and Indonesia (2004). The second plate boundary of concern is the Queen Charlotte Fault that extends north of Vancouver Island along the coast of Haida Gwaii. In 1949 this fault generated Canada's largest historically recorded earthquake (M=8.1). On October 27 2012, a M=7.8 earthquake beneath Haida Gwaii spawned a small tsunami and highlighted the existence of an additional, major thrust fault dipping to the northeast beneath Moresby Island.