Russia oil leak: What is permafrost, and why does its thawing pose risk to the world?

News: The principal reason that led to the 20,000-tonne oil leak at an Arctic region power plant in Russia is being recognised is the sinking of ground surface due to permafrost thaw.

Facts:

• Permafrost: It is a ground that remains completely frozen at 0 degrees Celsius or below for at least two years.It is defined solely based on temperature and duration.
• Where are they found? Permafrost are most common in regions with high mountains and in Earth’s higher latitudes—near the North and South Poles.
• What is Permafrost made of? It is made of a combination of soil, rocks and sand that are held together by ice.The soil and ice in permafrost stay frozen all year long.
  • A layer of soil on top of permafrost does not stay frozen all year. This layer called the active layer, thaws during the warm summer months and freezes again in the fall.
• How Climate Change is affecting Permafrost? As Earth’s climate warms, the permafrost is thawing.That means the ice inside the permafrost melts, leaving behind water and soil.
• Effects of Thawing Permafrost:
  • Ground becomes unstable which leads to landslides, floods, infrastructure damage and threat to survival of indigenous people & animals.
  • Release of greenhouse gases by decomposition of organic leftover under permafrost.
  • Release of ancient bacteria and viruses into the atmosphere.