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，它从加利福尼亚州北部延伸到温哥华岛北部，大约在海岸线以西约150公里处。该板块边界经历了平均约550年一次的9级以上地震，能够引发海啸和地面震动，可与最近在日本(2011年)和印度尼西亚(2004年)发生的大地震相媲美。第二个令人担忧的板块边界是夏洛特女王断层，该断层沿着海达瓜伊岛海岸延伸到温哥华岛北部。1949年，这条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，海达瓜伊岛下7.8级地震引发了一场小海啸，并突显了莫尔兹比岛下向东北倾斜的另一条主要逆冲断层的存在。

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.