| Popis: |
Potential tsunami hazard for the Alaska Peninsula communities of Chignik and Chignik Lagoon is evaluated by numerically modeling the extent of inundation from tsunami waves generated by hypothetical earthquake sources. Worst-case hypothetical scenarios are defined by analyzing results of a sensitivity study of the tsunami dynamics related to various slip distributions along the Alaska-Aleutian megathrust. The worst-case scenarios for Chignik area communities are thought to be thrust earthquakes along the Alaska Peninsula with their greatest slip at 5-35 km (3.1-22 mi) depth. We also consider Tohoku-type ruptures and an outer-rise rupture along the Alaska Peninsula. The maximum predicted water depth on Anderson Street in Chignik Bay is about 31 m (102 ft), while the water depth on Henry Street in Chignik Lagoon is about 11 m (36ft). Maximum current velocity in the ocean could exceed 9 m/s (17 kt) and significant wave action could continue for at least 8 hours after the earthquake. Results presented here are intended to provide guidance to local emergency management agencies in tsunami inundation assessment, evacuation planning, and public education to mitigate future tsunami hazards. |
