Observing a catastrophic thermokarst lake drainage in northern Alaska

Permafrost and Periglacial Processes
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Abstract

The formation and drainage of thermokarst lakes have reshaped ice-rich permafrost lowlands in the Arctic throughout the Holocene. North of Teshekpuk Lake, on the Arctic Coastal Plain of northern Alaska, thermokarst lakes presently occupy 22.5% of the landscape, and drained thermokarst lake basins occupy 61.8%. Analysis of remotely sensed imagery indicates that nine lakes (>10 ha) have drained in the 1,750 km2 study area between 1955 and 2014. The most recent lake drainage was observed using in situ data loggers providing information on the duration and magnitude of the event, and a nearby weather station provided information on the environmental conditions preceding the lake drainage. Lake 195 (L195), an 80 ha thermokarst lake with an estimated water volume of ~872,000 m3, catastrophically drained on 05 July 2014. Abundant winter snowfall and heavy early summer precipitation resulted in elevated lake water levels that likely promoted bank overtopping, thermo-erosion along an ice-wedge network, and formation of a 9 m wide, 2 m deep, and 70 m long drainage gully. The lake emptied in 36 hours, with 75% of the water volume loss occurring in the first ten hours. The observed peak discharge of the resultant flood was 25 m3/s, which is similar to that in northern Alaska river basins whose areas are more than two orders of magnitude larger. Our findings support the catastrophic nature of sudden lake drainage events and the mechanistic hypotheses developed by J. Ross Mackay.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Observing a catastrophic thermokarst lake drainage in northern Alaska
Series title Permafrost and Periglacial Processes
DOI 10.1002/ppp.1842
Volume 26
Issue 2
Year Published 2015
Language English
Publisher John Wiley & Sons
Publisher location Chichester, Sussex, England
Contributing office(s) Alaska Science Center Geography
Description 10 p.
First page 119
Last page 128
Country United States
State Alaska
Other Geospatial Arctic Coastal Plain
Online Only (Y/N) N
Additional Online Files (Y/N) N