Abstract
The majority of slope failures in coastal Alaska occur as debris slides and avalanches in small hillslope depressions. During fall storms, positive pore water pressures develop within the soil mantle increasing the probability of slope failure. Shallow groundwater levels in two steep, forested hillslope depressions were measured continuously during several storms in fall 1980 and fall 1981. The rapid response of groundwater to precipitation was greater than could be predicted by vertical infiltration of rain water, suggesting that rapid interflow may be occurring through discontinuous networks of soil macropores and subsurface pipes creating zones of positive pore water pressure. -from Author