• Image of mountains and river

    Gates Of The Arctic

    National Park & Preserve Alaska

There are park alerts in effect.
show Alerts »
  • Emergency Sheep Hunting Closure in Units 23 & 26(A)

    All sheep seasons in Game Management Units 23 and 26(A) for all resident and nonresident hunters are closed due to severe decline in sheep numbers in the contiguous populations of the De Long and Schwatka Mountains. More »

Permafrost

Permafrost-ground-ice,-ice-wedges-Dave-Swanson-750px-title
 
 

Permafrost is ground that stays frozen year round and underlies most of the Park. It dramatically shapes the landscape by determining where plants grow, the flow of surface water, and ultimately where animals live. In the summer, the upper foot or two of ground thaws; this is known as the active layer. However, because the ground beneath the active layer stays frozen, water collects on top of flat ground instead of draining away. There are many boggy areas, wetlands, and small lakes in the arctic landscape, in spite of the fact that most lowlands receive just 10 to 20 inches of rain and snow per year - less than most places in the eastern and midwestern United States.

Thawing of permafrost has many consequences, such as drainage of lakes, soil erosion, changing river patterns, increased sedimentation of streams and lakes, and changes in vegetation. All of these consequences can considerably affect how humans move across the landscape and the availability of wildlife and other food sources.

Permafrost monitoring involves looking at long-term changes in permafrost extent and temperature, active layer depth, and permafrost-related landforms. Results of this monitoring will help us understand broad changes in ecosystems that could occur as a result of climate change, such as changes in the area of ponds and lakes, the turbidity of streams, and the density of vegetation. Permafrost is a "Vital Sign" for the Arctic Network Inventory and Monitoring Program (ARCN).

Information gathered from this monitoring effort will be used to:

  • Determine trends through time in ground temperatures at representative sites. This will indicate whether the permafrost is stable or likely to thaw.
  • Monitor the area occupied by slumps and landslides caused by thaw of permafrost.
  • Map permafrost features from satellite images, compare them to old aerial photographs, and track changes in the future on satellite images.
 
Multimedia


 
Permafrost video

Permafrost - Its all over the place. Discover how to know it when you see it.

 

Pingos - Sounds like an exotic dessert. Watch the video and discover the magic of Pingos.

 

Ice Wedges - Discover the how and why of ice wedges in the arctic.

 

Did You Know?

A land status map showing the federal units that protect the Brooks Range.

Gates of the Arctic National Park and Preserve is the central component of the 700 square mile protected Brooks Range. Arctic National Wildlife Refuge is to the east, and the Noatak Preserve is to the west.