Notably, permafrost in northern Alaska is naturally colder and more continuous than permafrost in the interior region. Permafrost temperature can vary depending on local environmental factors such as soil type, vegetation characteristics, and snow cover depth. This collection of sites is not necessarily representative of all types of permafrost or all temperature trends throughout Alaska. Logistical issues caused minor fluctuation in the exact timing of when measurements were collected each year, which could also add some uncertainty to the results. Additionally, some sites were not measured every year, creating gaps of two to four years, but all the sites included in this indicator meet minimum data completeness required for long-term change calculation. Some borehole sites used in this indicator rely on data collected at depths less than 65 feet, which may be influenced by seasonal or short-term surface temperature change. This contributes to further global climate change. Additionally, organic matter (like the remains of plants) currently frozen in the permafrost will start to decompose when the ground thaws, resulting in methane and carbon dioxide being emitted into the atmosphere. 4 Infrastructure damage and erosion, due in part to permafrost thaw, has already caused some communities in western and southern Alaska to have to relocate. Infrastructure such as roads, buildings, and pipes could be damaged as permafrost thaws. For instance, as ice-filled permafrost thaws, it can turn into a mud slurry that cannot support the weight of the soil and vegetation above it. While the impacts of climate change on permafrost vary at regional and local scales, permafrost thawing has been observed in many locations around the world.Ī thawing permafrost layer can lead to severe impacts on people and the environment.

3 A warming climate has brought higher temperatures to Alaska and other areas with permafrost, causing some permafrost to thaw. The seasonal timing, amount, and extent of snow cover (see the Snow Cover indicator) also affect permafrost. 2 A key characteristic affecting the state of permafrost is the temperature at the ground surface and shallow depths. In Alaska, about 80 percent of the ground has permafrost underneath it. 1 Permafrost occurs in many different forms with various amounts of ice (continuous and discontinuous) and is mainly found in areas near the Arctic. It usually lies below an “active layer” of soil that freezes and thaws every year. Permafrost is defined as rock or soil with ice that stays frozen for two or more years.

Changes in permafrost temperature shown in this indicator are consistent with changes observed in Russia, Canada, and other parts of the Arctic.

Overall, permafrost temperatures have increased at an average rate of 0.6☏ per decade. The Livengood site in interior Alaska was the only site to get cooler over the period of record, though only slightly.

The Deadhorse site in northern Alaska had the highest rate of temperature change, at +1.5☏ per decade.The increasing rate of change in the north is consistent with changes in air temperatures, which have increased more quickly in northern Alaska than in other parts of the state (see Figure 3 of EPA’s U.S. In general, permafrost has warmed more quickly in northern Alaska than interior Alaska (see Figure 2).Warming was statistically significant at 13 of the 14 boreholes that had increases. Between 19, permafrost temperatures increased at 14 of the 15 borehole sites shown in this indicator (see Figures 1 and 2).

Rock weather indicator