Close Window

Lake Change in the 13 Boreal and Arctic Study Regions in the recent ~60 years

Prajna Lindgren, University of Alaska Fairbanks, pregmi@alaska.edu
Franz Meyer, University of Alaska Fairbanks, fjmeyer@alaska.edu
Katey Walter Anthony, University of Alaska Fairbanks, kmwalteranthony@alaska.edu (Presenter)
Lisa Wirth, University of Alaska Fairbanks, lisa@gina.alaska.edu
Andrew Herbst, University of Alaska Fairbanks, amherbst@alaska.edu

Permafrost in the northern latitude stores a significant amount of carbon. However, formation and expansion of lakes in ice-rich permafrost region facilitate the release of soil-stored carbon in the form of methane (CH4), an important greenhouse gas. Previous studies have shown that lakes are changing at a greater rate in the last few decades due to warming permafrost and many regions have experienced significant lake expansion consequently increasing the release of old permafrost carbon. Therefore, in this study, we utilized historic aerial images (1 m spatial resolution) acquired in the 1950s and recent SPOT satellite images acquired post-2009 (2.5 spatial resolution) to map historic and modern lake margins using semi-automated object-oriented image analysis in 13 different sites distributed over Alaska to produce fine-scale maps of lake area change. These sites include (1) Barrow Peninsula, (2) North of Teshupuk, (3) Atqasuk, (4) Inigok Fish Creek in the north, (5) Minto, (6) Fairbanks, (7) Standard Dunbar, (8) Fox in the interior, (9) Gerstle, (10) Moon, (11) Mansfield, (12) Northway Boundary in the east, and (13) Northern Seward Peninsula in the west. The preliminary results show that there is both lake expansion and shrinkage. The interior of Alaska shows major lake expansion especially in Fairbanks area, an increase in lake area by approx. 42%, while the eastern study sites show mostly lake area shrinkage, with the highest lake area loss in Moon by approx. 15%. We have also found that the location of methane seeps and their density align very well with expanding part of the lakes in Fairbanks. The mapping on the rest of the study sites is still a work in progress, however for some sites like Barrow in the north, our initial interpretation shows that many lakes are experiencing lake expansion. Our next step, after creating lake change map products, will be to compare the lake expansion in these regions with CH4 seep locations that we have observed in the field as well as mapped in the recent high-resolution aerial and satellite imagery.

Associated Project(s): 

Poster Location ID: 3

Session Assigned: Carbon Dynamics

 


Close Window