Hydrologic and mass-movement hazards near McCarthy, Wrangell-St Elias National Park and Preserve, Alaska
Jones SH and Glass RL. 1993. Hydrologic and mass-movement hazards near McCarthy, Wrangell-St Elias National Park and Preserve, Alaska. U.S. Geological Survey (USGS) Water Resources Investigations Report. 93-4078. United States Geological Survey. Anchorage, AK
McCarthy, Alaska, is at the confluence of McCarthy Creek and the Kennicott River, about 1 mile from the terminus of Kennicott Glacier in the Wrangell-St. Elias National Park and Preserve. McCarthy Creek and Kennicott River basins are prone to several natural hazards including floods; formation and failure of natural dams; stream erosion and sediment deposition; snow avalanches; aufeis; and the mass wasting of rock, soil, and debris. Lowlying areas along the Kennicott River flood annually, commonly during late July or early August, as a result of outbursts from glacier-dammed lakes, but floods can occur during any month of the year. Flood plains along McCarthy Creek and its tributaries are frequently flooded and are prone to rapid erosion and deposition during intense rainfall and periods of rapid snowmelt. Sediments from continual mass wasting accumulate in stream channels and are mobilized during floods. Severe lateral erosion, scour, and deposition resulting from floods in September 1980 and August 1985 destroyed bridges near McCarthy. Several historical structures at McCarthy were jeopardized by the rapidly eroding northern streambank of McCarthy Creek. Flood discharges were determined using the slope-area method at two high-gradient reaches on the Kennicott River, four on McCarthy Creek, and one on Nikolai Creek. During the flood of September 13,1980, peak discharge for McCarthy Creek at McCarthy was 4,500 cubic feet per second.
- Type
- Published Report
- Authors
- Jones, Stanley; Glass, Roy
- Date of Issue
- 1993
- Publisher
- United States Geological Survey
- Units
- HIST , WRD , WRST
- Keywords
- Avalanches, ehistory, Floods, Geologic Hazards, Geology, History, Hydrology, Hydrology(General), IAR, Kennicott River, Kennicott River basin, Landslides, Maps, mass-movement, McCarthy, McCarthy Creek, McCarthy Creek basin, Nikolai Creek, Photographs, Physical Sciences, Rivers, Streams, Water, WRBIB