How do wildfires burn underground and how are they extinguished?

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1. 1

   Peat fires contribute disproportionately to Siberian fire carbon emissions.

   Science advances (Khairoun et al.)Published Mar 18, 2026Checked Oct 10, 2026

   “Arctic and boreal fires are critical threats to terrestrial carbon reservoirs, particularly peat fires that trigger long-term irrecoverable carbon losses and permafrost thaw. However, the occurrence of peat fires and their associated carbon emissions remain highly uncertain. 30-meter satellite-derived maps of burned area and peatland coverage reveal that Siberian fires burned over 107 million hectares during the 2001 to 2023 period, with peat fires accounting for up to one-third of this area. These peat fires emitted 1.24 ± 0.06 petagram of carbon, largely exceeding conventional datasets' estimates. We found that anomalous dry and warm climatic conditions represent the primary driver of extreme peat fire seasons and that overwintering of 2020's late-season peat fires substantially contributed to extensive fires of 2021. Peat fires, especially those in Arctic regions, exhibit a pronounced sensitivity to extreme weather, posing a critical threat to the stability of permafrost peatlands and their large carbon stocks.”

2. 2

   How drones are hunting fires hidden beneath the Cairngorms

   BBC NewsPublished Oct 10, 2026Checked Oct 10, 2026

   “Dramatic flames from the huge Cairngorms wildfire in July have disappeared - but hot spots can continue to burn beneath the earth.”

3. 3

   Root fire (Wikipedia)

   WikipediaPublished Sep 29, 2026Checked Oct 10, 2026

   “A root fire (also known as a ground fire) is a wildfire caused by the burning of tree roots. It is a wildfire caused through underground burns generally triggered by off-trail camping or other causes. They can pose an often overlooked dangerous threat. Because a root fire burns underground, its smoke may appear just as smouldering indistinguishable from the wake of a forest fire. These fires can reignite a wildfire or cause other natural hazards, and are also dangerous to humans and animals if trodden over, because the extreme heat can cause the soil to collapse. Root fires are similar to peat fires, and have the same function in maximizing the risk and spread of wildfires. Peat fires, however, can cause even more environmental issues due to their composition, impacting the environment, atmosphere, and flora and fauna where they occur.”

4. 4

   Impact of Snow on Underground Smoldering Wildfire in Arctic-Boreal Peatlands.

   Environmental science & technology (Qin et al.)Published Feb 6, 2025Checked Oct 10, 2026

   “Despite the critical role of fire-snow interactions in these processes, our understanding of them remains limited. Herein, we conducted small-scale outdoor experiments (20 × 20 × 20 cm3) at subzero temperatures (-5 ± 5 °C) to investigate the impact of natural snowfall and accumulated snow layers (up to 20 cm thick) on shallow smoldering peat fires. We found that even heavy natural snowfalls (a maximum water equivalent snowfall intensity of 1.1 mm/h or a 24 h accumulated snowfall water equivalent precipitation of 7.9 mm) cannot suppress a shallow smoldering peat fire. A thick snow cover on the peat surface can extract heat from the burning front underneath, and the minimum thickness of the snow layer to extinguish the peat fire was found to be 9 ± 1 cm at subzero temperatures, agreeing well with the theoretical analysis. Furthermore, larger-scale field demonstrations (1.5 × 1.5 m2) were conducted to validate the small-scale experimental phenomena. This work helps us to understand the interactions between fire and snow and reveals the persistence of smoldering wildfires under cold environments.”

5. 5

   Peat (Wikipedia)

   WikipediaPublished Oct 7, 2026Checked Oct 10, 2026

   “Peat is an accumulation of partially decayed vegetation or organic matter. It is unique to natural areas called peatlands, bogs, mires, moors, or muskegs. Sphagnum moss, also called peat moss, is one of the most common components in peat, although many other plants can contribute. The biological features of sphagnum mosses act to create a habitat aiding peat formation, a phenomenon termed 'habitat manipulation'. Soils consisting primarily of peat are known as histosols. Peat forms in wetland conditions, where flooding or stagnant water obstructs the flow of oxygen from the atmosphere, slowing the rate of decomposition. Peat properties such as organic matter content and saturated hydraulic conductivity can exhibit high spatial heterogeneity. Peatlands, particularly bogs, are the primary source of peat; although less common, other wetlands, including fens, pocosins and peat swamp forests, also deposit peat. Landscapes covered in peat are home to specific kinds of plants, including Sphagnum moss, ericaceous shrubs and sedges.”