EPOW - Ecology Picture of the Week

The Tundra Lakes of Kobuk

Tundra Lakes, Kobuk Valley National Park
Alaska, USA

Explanation:   Here is a vista of Kobuk Valley National Park in northwest Alaska.  We are seeing a vast landscape of tundra and thousands of lakes big and small.

Why are there so many lakes here?  The water dynamics of the arctic is unlike anywhere else.  There are ponds and lakes that form from thermokarst and ice wedge processes that cause the local thawing of permafrost and deepening of the "active layer" of unfrozen, and often saturated, ground.  Some other of these water bodies form local flooding when a lake or pond drains across the landscape when an outlet forms.  

As lakes drain, they may leave behind a smaller pond in the deeper center, and vegetation gets a shot at the organic-rich soil.  Some ponds drain and reform over dry and wet years.  Some lakes and ponds form as oxbows when a bend in a river gets cut off.  

This landscape is incredibly dynamic!

Information:
     Karlsson, J.M., F. Jaramillo, and G. Destouni.  2015.  Hydro-climatic and lake change patterns in Arctic permafrost and non-permafrost areas.  Journal of Hydrology 529(1):134-145. 
     Necsoui, M., C.L. Dinwiddie, G.R. Walter, D.M. Hooper, and R.N. McGinnis.  2009.  Multispectral remote sensing technologies applied to assess recent aeolian activity and thaw lake changes in Kobuk River Valley, Alaska.  American Geophysical Union, Fall Meeting 2009, abstract id. U41C-0060.  

Acknowledgment:
     My thanks to Ecologist David Swanson of the National Park Service for having provided his expert knowledge on the hydrodynamics of the region.