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JOURNAL OF GEOPHYSICAL RESEARCH,
VOL. 116,
G00M03,
13 PP., 2011
doi:10.1029/2011JG001666
Modern thermokarst lake dynamics in the continuous permafrost zone, northern Seward Peninsula, Alaska
- Landscape scale assessment of thermokarst lake expansion and drainage rates
- Widespread drainage of thermokarst lakes in the continuous permafrost zone
- Thermokarst lake dynamics impact the northern high latitude carbon cycle
B. M. Jones
Geophysical Institute, University of Alaska Fairbanks, Fairbanks, Alaska, USA
Alaska Science Center, U.S. Geological Survey, Anchorage, Alaska, USA
G. Grosse
Geophysical Institute, University of Alaska Fairbanks, Fairbanks, Alaska, USA
C. D. Arp
Institute of Northern Engineering, University of Alaska Fairbanks, Fairbanks, Alaska, USA
M. C. Jones
Institute of Northern Engineering, University of Alaska Fairbanks, Fairbanks, Alaska, USA
K. M. Walter Anthony
Institute of Northern Engineering, University of Alaska Fairbanks, Fairbanks, Alaska, USA
V. E. Romanovsky
Geophysical Institute, University of Alaska Fairbanks, Fairbanks, Alaska, USA
Quantifying changes in thermokarst lake extent is of importance for understanding the permafrost-related carbon budget, including the potential release of carbon via lake expansion or sequestration as peat in drained lake basins. We used high spatial resolution remotely sensed imagery from 1950/51, 1978, and 2006/07 to quantify changes in thermokarst lakes for a 700 km2 area on the northern Seward Peninsula, Alaska. The number of water bodies larger than 0.1 ha increased over the entire observation period (666 to 737 or +10.7%); however, total surface area decreased (5,066 ha to 4,312 ha or −14.9%). This pattern can largely be explained by the formation of remnant ponds following partial drainage of larger water bodies. Thus, analysis of large lakes (>40 ha) shows a decrease of 24% and 26% in number and area, respectively, differing from lake changes reported from other continuous permafrost regions. Thermokarst lake expansion rates did not change substantially between 1950/51 and 1978 (0.35 m/yr) and 1978 and 2006/07 (0.39 m/yr). However, most lakes that drained did expand as a result of surface permafrost degradation before lateral drainage. Drainage rates over the observation period were stable (2.2 to 2.3 per year). Thus, analysis of decadal-scale, high spatial resolution imagery has shown that lake drainage in this region is triggered by lateral breaching and not subterranean infiltration. Future research should be directed toward better understanding thermokarst lake dynamics at high spatial and temporal resolution as these systems have implications for landscape-scale hydrology and carbon budgets in thermokarst lake-rich regions in the circum-Arctic.
Received 24 January 2011; accepted 16 June 2011; published 20 September 2011.
Citation: (2011), Modern thermokarst lake dynamics in the continuous permafrost zone, northern Seward Peninsula, Alaska, J. Geophys. Res., 116, G00M03, doi:10.1029/2011JG001666.
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