Outburst Floods from Glacial Lake Missoula

Abstract

The Pleistocene outburst floods from glacial Lake Missoula, known as the “Spokane Floods”, released as much as 2184 km 3 of water and produced the greatest known floods of the geologic past. A computer simulation model for these floods that is based on physical equations governing the enlargement by water flow of the tunnel penetrating the ice dam is described. The predicted maximum flood discharge lies in the range 2.74 × 10 6 −13.7 × 10 6 m 3 sec −1 , lending independent glaciological support to paleohydrologic estimates of maximum discharge.