Timing and patterns of basin infilling as documented in Lake Powell during a drought

Published

Journal Article

Between 1999 and 2005, drought in the western United States led to a >44 m fall in the level of Lake Powell (Arizona-Utah), the nation's second-largest reservoir. River discharges to the reservoir were halved, yet the rivers still incised the tops of deltas left exposed along the rim of the reservoir by the lake-level fall. Erosion of the deltas enriched the rivers in sediment such that upon entering the reservoir they discharged plunging subaqueous gravity flows, one of which was imaged acoustically. Repeat bathymetric surveys of the reservoir show that the gravity flows overtopped rockfalls and formed small subaqueous fans, locally raising sediment accumulation rates 10-100-fold. The timing of deep-basin deposition differed regionally across the reservoir with respect to lake-level change. Total mass of sediment transferred from the lake perimeter to its bottom equates to ∼22 yr of river input. © 2008 The Geological Society of America.

Full Text

Duke Authors

Cited Authors

  • Pratson, L; Hughes-Clarke, J; Anderson, M; Gerber, T; Twichell, D; Ferrari, R; Nittrouer, C; Beaudoin, J; Granet, J; Crockett, J

Published Date

  • December 1, 2008

Published In

Volume / Issue

  • 36 / 11

Start / End Page

  • 843 - 846

Electronic International Standard Serial Number (EISSN)

  • 0091-7613

International Standard Serial Number (ISSN)

  • 0091-7613

Digital Object Identifier (DOI)

  • 10.1130/G24733A.1

Citation Source

  • Scopus