Slumping of the entire Turnagain Heights subdivision in Anchorage occurred when soil liquefied during the earthquake. The subdivision was located on a bluff above Cook Inlet. A section of earth 2,576 m long and 273 m wide broke loose and slid 21 m toward Cook Inlet. At least 75 houses were destroyed. The most probable explanation of the landslide was a loss of strength in underlying soils from the ground shaking. Sand lenses liquefied and clay soils weakened and moved down slope in a complicated motion. Slope failure began 1.5 to 2.0 minutes after the start of the earthquake.

Image Credit: NOAA National Geophysical Data Center