Permafrost

Exposed permafrost
Exposed yedoma permafrost exposed along an eroded Arctic coast.
Permafrost is permanently frozen ground that underlies much of the landscape in the Arctic. It affects nearly everything in the Arctic ecosystem, including soils, vegetation, water, and wildlife. During summer months, the top layer of soil thaws creating a wet landscape with rapid runoff. The striking quilt-like pattern of permafrost landscapes is caused by the build-up and thawing of ice in the ground, which produces pits, ponds, and landslides. Annual permafrost thaw is normal, but thawing is expected to increase with climate change. The National Park Service is monitoring permafrost and the land dynamics associated with permafrost thaw to better understand the changes and the effects on the landscape.

Permafrost Terminology

Permafrost
ground that remains frozen longer than two consecutive years; ground that doesn't thaw in the summer

Yedoma
an organic-rich Pleistocene-age permafrost with high ice content

Active Layer
in areas with permafrost, the top portion of the soil that thaws and refreezes each year

Ice Wedge
polygon-like pattern on the landscape associated with permafrost caused by repeated cycles of melting, freezing, and cracking

Thermokarst
landscape formations associated with permafrost thaw

Pingo
an earth-covered mound of ice, which creates topography and provides habitat for arctic foxes

Slump
a term that refers to the sagging or degradation of the landscape caused by permafrost thaw

Hydrology
the study of the location, movement, and quality of water on earth; heavily influenced by permafrost in Arctic systems

Erosion
the transport of soil and rock from the earth's surface by wind or water; a significant effect of permafrost thaw
Aerial view of permafrost polygon patterns in the tundra.
Monitoring Arctic Permafrost

Permafrost underlies most of the Arctic Network and affects nearly everything, from soils and vegetation to water and wildlife.

A "drunken forest" with trees leaning due to permafrost melt.
Monitoring Central Alaska Permafrost

The Central Alaska Network monitors permafrost to track changes over time, focusing on the thermal and physical state of permafrost.

Learn more about permafrost

Showing results 1-10 of 38

  • Boreal shrub and tree expansion promotes soil warming

    • Type: Article
    • Offices: Arctic Inventory & Monitoring Network, Central Alaska Inventory & Monitoring Network
    Arctic, boreal forest

    Read the abstract and get the link to an article published in Environmental Research Letters that connects vegetation shift to warming Arctic and Boreal soils under vegetation. Kropp, H., M. M. Loranty, S. M. Natali, A. L. Kholodov, A. V. Rocha, … J. A. O’Donnell … et al. 2020. Shallow soils are warmer under trees and tall shrubs across Arctic and Boreal ecosystems. Environmental Research Letters.

  • Increasing temperatures in Alaska national parks

    • Type: Article
    • Offices: Arctic Inventory & Monitoring Network, Central Alaska Inventory & Monitoring Network
    A researcher closely studies the tundra.

    Read the abstract and link to a paper that describes increasing temperatures and their effects on permafrost in northern parks: Swanson, D. K., P. J. Sousanes, and K. Hill. 2021. Increased mean annual temperatures in 2014-2019 indicate permafrost thaw in Alaskan national parks. Arctic, Antarctic, and Alpine Research 53(1): 1-19.

  • Arctic Inventory & Monitoring Network

    The role of old carbon in aquatic food webs

    • Type: Article
    • Offices: Arctic Inventory & Monitoring Network
    A bucket full of different kinds of small fishes.

    Read a summary and get the link to this article that looks at the use of old carbon in Arctic fish food webs and potential impacts of climate change: Stanek, A.E., Carey, M.P., O'Donnell, J.A., Laske, S.M., Xu, X., Dunton, K.H., von Biela, V.R. 2024. Arctic fishes reveal a gradient in radiocarbon content and use. Limnology and Oceanography Letters.

  • New Research Shows Why Arctic Streams Are Turning Orange

    • Type: Article
    • Locations: Gates Of The Arctic National Park & Preserve, Kobuk Valley National Park, Noatak National Preserve
    • Offices: Arctic Inventory & Monitoring Network, Inventory and Monitoring Division
    Rushing stream where the water is bright orange. Mountains and snow line the horizon.

    In the pristine Brooks Range in Arctic Alaska, streams are turning bright orange and fish are disappearing, threatening the well-being of local communities. A recent scientific paper reveals why.

  • Metals released from thawing permafrost are rusting Arctic streams

    • Type: Article
    • Locations: Gates Of The Arctic National Park & Preserve, Kobuk Valley National Park, Noatak National Preserve
    • Offices: Arctic Inventory & Monitoring Network
    An orange stream joins a blue-water stream.

    Read the abstract and get the link to a published paper on how permafrost thaw is releasing metals into streams and turning them orange: O'Donnell, J. A., M. P. Carey, J. C. Koch, C. Baughman, K. Hill, C. E. Zimmerman, P. F. Sullivan, R. Dial, T. Lyons, D. J. Cooper, and B. A. Poulin. 2024. Metal mobilization from thawing permafrost to aquatic ecosystems is driving rusting of Arctic streams. Communications Earth & Environment 5: 268.

  • Permafrost Thaw Slumps in the Noatak Valley

    • Type: Article
    • Locations: Gates Of The Arctic National Park & Preserve, Noatak National Preserve
    • Offices: Arctic Inventory & Monitoring Network
    An enhanced aerial map of thaw slumps over time.

    Retrogressive thaw slumps, small landslides caused by thaw and subsidence of permafrost, are dramatic features on the Arctic landscape. They can impact water quality in streams and lakes. Resource brief, 2023

  • Nutuvukti Lake and Fen

    • Type: Article
    • Locations: Gates Of The Arctic National Park & Preserve
    • Offices: Arctic Inventory & Monitoring Network
    A large lake with a mountain and reflection.

    Nutuvukti Lake is a unique and interesting place in Gates of the Arctic National Park and Preserve. The lake lies in a trough between two mountain ridges covered with dwarf subarctic spruce forest and alpine tundra. Six miles long, Nutuvukti Lake is smaller than its more famous neighbor, Walker Lake, but is still one of the largest lakes in northern Alaska and home to lake trout, arctic grayling, arctic char, northern pike, and whitefish.

  • Arctic Inventory & Monitoring Network

    Ice wedges surprisingly stable over the past decade

    • Type: Article
    • Offices: Arctic Inventory & Monitoring Network
    A diagram of ice wedge polygons.

    When ice wedges melt, ponds can form around the margins of the ice-wedge polygons. We use aerial photographs and satellite images to make maps of the distribution of ponds around ice-wedge polygons in three study areas. Resource brief, 2023

  • Beavers and the Arctic carbon cycle

    • Type: Article
    • Locations: Noatak National Preserve
    • Offices: Arctic Inventory & Monitoring Network
    A scientist collects data from an Arctic stream.

    Read the abstract and link to a peer reviewed science article on methane emmissions in beaver ponds and streams in the Arctic: Clark, J. A., K. D. Tape, L. Baskaran, C. Elder, C. Miller, K. Miner, J. A. O'Donnell, and B. M. Jones. 2023. Do beaver ponds increase methane emissions along Arctic tundra streams? Environmental Research Letters 18: 075004.

  • Linkages Between Global Climate Change and Dissolved Organic Carbon in Arctic Lakes

    • Type: Article
    A boreal forest with lake and mountains.

    In northern latitudes, permafrost has provided important carbon storage for thousands of years. But as rising temperatures warm the soil, carbon is rapidly released. The Arctic is a key location to investigate the impact on global climate change and carbon cycles related to thawing permafrost. Read more from Stolpman et al. 2021. First pan-Arctic assessment of dissolved organic carbon in lakes of the permafrost region. Biogeosciences 18: 3917-3936.

Tags: permafrost permafrost permafrost thaw
Back to top

Last updated: April 3, 2024

Experience More

Subjects

Parks

Tools

Stay Connected