- The principal reason that led to the recent 20,000-tonne oil leak at an Arctic region power plant in Russia that is now being recognized is the sinking of ground surface due to permafrost thaw.
What is permafrost?
- ground that remains completely frozen at 0 degrees Celsius or below for at least two years.
- solely based on temperature and duration.
- consisting of soil, sand, and rock held together by ice, is believed to have formed during glacial periods dating several millennia.
- below 22 per cent of the land surface on Earth, mostly in polar zones and regions with high mountains.
- spread across 55 per cent of the landmass in Russia and Canada, 85 per cent in the US state of Alaska, and possibly the entirety of Antarctica.
- At lower latitudes, permafrost is found at high altitude locations such as the Alps and the Tibetian plateau.
Other Details on Permafrost
- While permafrost itself is always frozen, the surface layer that covers it (called the “active layer”) need not remain frozen.
- In Canada and Russia, for example, colourful tundra vegetation carpet over permafrost for thousands of kilometres.
- thickness reduces progressively towards the south,
- affected by a number of other factors, including the Earth’s interior heat, snow and vegetation cover, presence of water bodies, and topography.
- A study has shown that every 1 degree Celsius rise in temperature can degrade up to 39 lakh square kilometre due to thawing.
- When permafrost thaws, microbes start decomposing this carbon matter, releasing greenhouse gases like methane and carbon dioxide.
- release ancient bacteria and viruses into the atmosphere as they unfreeze.
How Does Climate Change Affect Permafrost?
As Earth’s climate warms, the permafrost is thawing. That means the ice inside the permafrost melts, leaving behind water and soil.
Thawing permafrost can have dramatic impacts on our planet and the things living on it. For example:
- When permafrost is frozen, it’s harder than concrete. However, thawing permafrost can destroy houses, roads and other infrastructure.
- plant material in the soil—called organic carbon—can’t decompose, or rot away. As permafrost thaws, microbes begin decomposing this material. This process releases greenhouse gases like carbon dioxide and methane to the atmosphere.
- When permafrost thaws, so do ancient bacteria and viruses in the ice and soil. These newly-unfrozen microbes could make humans and animals very sick. Scientists have discovered microbes more than 400,000 years old in thawed permafrost.
NASA’s Soil Moisture Active Passive, or SMAP, mission orbits Earth collecting information about moisture in the soil.
- It measures the amount of water in the top 2 inches (5 centimeters) of soil everywhere on Earth’s surface.
- It can also tell if the water within the soil is frozen or thawed.
- SMAP’s measurements will help scientists understand where and how quickly the permafrost is thawing.