PRINCE WILLIAM SOUND EARTHQUAKE, MARCH 28, 1964

Hanning Bay Fault Scarp, Alaska

[FAULTS] This view is looking southwest along the Hanning Bay fault scarp on southwest Montague Island in Prince William Sound. The Hanning Bay fault was reactivated during the earthquake. Its trace is marked by a 10- to 15-foot high (3.0 m to 4.5 m) bedrock scarp which trends obliquely across the field of view from the right foreground to the left background. The fault trace lies between the uplifted wave-cut surface that is coated white by desiccated calcareous marine organisms and borders the open ocean, and the area of brown sand and silt in the cove. The ground northwest of the fault (right side of photo) was displaced upward as much as 16 feet (4.8 m) with respect to the ground southeast of the fault during the earthquake, but both sides of the fault were uplifted with respect to sea level due to general tectonic uplift of the region. The fault plane dips steeply northwest, or is vertical. Photograph Credit: U.S. Geological Survey, Menlo Park, CA.