SEISMIC POTENTIAL OF THE QUEEN-CHARLOTTE-ALASKA-ALEUTIAN SEISMIC ZONE

The 5000 km long Queen Charlotte-Alaska-Aleutian seismic zone is subdivided into 17 unequally sized segments. Their boundaries are delineated based on the prior distribution of large and great earthquakes. The 17 segments are chosen to represent areas likely to be ruptured by "characteristic' earthquakes. Computations indicate seven areas that have high (ie, ≥60%) conditional probabilities for the recurrence of either large or great earthquakes within the next 20 years (1988-2008). These areas include Cape St. James, Yakataga, the Shumagin Islands, Unimak Island, and the Fox, Delarof, and Near Islands segments of the Aleutian arc. When a shorter time interval is considered (1988-1998), those segments more likely to rupture in large (MS 7-7.7) rather than great earthquakes have a high conditional probability. These areas include the Unimak, Fox, and Delarof Islands segments. -from Authors