Fault plane solutions and a strain release map imply that Southern Alaska performs in the role of a sink area unlike that of more classic trench-arc combinations. A broad, apparently interrelated zone of seismic activity extends from the Aleutian Trench to the base of the Alaska Range. While hypocentral distribution and relative seismicity imply that the entire area is performing as a sink for the North Pacific plate, fault plane solutions at the base of the Alaska Range are inconsistent with this premise. It is suggested that Cook Inlet and the lowlands north of Anchorage may represent an ancient trench.

First Page Preview

First page PDF preview
You do not currently have access to this article.