Syllabus: GS3/ Environment
Context
- Researchers studying sediment in Alaska’s Yukon River discovered that eroding permafrost is contributing mercury-laden sediments to the river.
About
- In the Arctic, plants absorb mercury, then die and become part of the soil, which eventually freezes into permafrost.
- Over thousands of years, mercury concentrations build up in the frozen soil until it thaws, an increasingly common occurrence due to climate change.
- Mercury amount in permafrost is more than the total of all oceans, soils, atmosphere and biosphere of the earth.
- Scholars have warned the world of an impressive ‘giant mercury bomb’ that may soon explode.
- The metal accumulates in the food chain specifically through people’s customary diets of fish and game.
What is Permafrost?
- Permafrost is essentially any ground that stays frozen — 0 degree Celsius or lower — for at least two years straight.
- It is composed 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.”
- Although the ground remains perennially frozen, permafrost regions aren’t always covered with snow.
- These permanently frozen grounds are often found in Arctic regions such as Greenland, Alaska (the United States), Canada, Russia, and Eastern Europe.
Consequences of Melting of Permafrost
- Melting permafrost alters the habitat for plants and animals, potentially disrupting local ecosystems and threatening biodiversity.
- Thawing permafrost causes the ground to become unstable, leading to the sinking or collapse of buildings, roads, pipelines, and other infrastructure.
- Permafrost acts as a freezer for ancient bacteria and viruses. Thawing could potentially release these pathogens, posing a risk of new or re-emerging diseases.
- As permafrost thaws, organic matter trapped in the frozen ground decomposes, releasing carbon dioxide and methane. This process accelerates global warming.
Mercury – Mercury is a naturally-occurring chemical element found in rock in the earth’s crust. 1. It is a shiny, silver-white metal, historically referred to as quicksilver, and is liquid at room temperature. – Mercury is released into the atmosphere through natural processes such as weathering of rocks, volcanic eruptions, geothermal activities, forest fires, etc. – Human activities, like burning of coal, oil and wood as fuel are responsible for much of the mercury that is released into the environment. – Mercury has toxic effects on the nervous, digestive and immune systems, and on lungs, kidneys, skin and eyes. |
Source: TOI
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