Geologic and hydrologic hazards in glacierized basins in North American resulting from 19th and 20th century global warming

ABSTRACT

Alpine glacier retreat resulting warming since the close of the Little Ice Age in the 19th and 20th centureis has increased the risk and incidence of some geologic and hydrologic hazards in mountainous alpine regions of North American. Abundant loose debris in recently deglaciated areas at the toe of alpine glaciers provides a ready sources of sediment during rainstorms or outburst floods. This sediment can cause debris flows and sedimentation problems in dowstream areas. Many glacier-dammed lakes have grown in size while ice dams have shrunk, resulting in greater risks of ice-dam-failure. The retreat and thinning of glacier ice has left oversteepened, unstable valley walls and has led to increased incidence of rock and debris avalanches (AU)