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Home / Science / Greenland ice sheet melted at unprecedented speed over the past 350 years or more – Axios

Greenland ice sheet melted at unprecedented speed over the past 350 years or more – Axios



According to a recent study by a research team from the US and the Netherlands, the extent of the recent melting of the Greenland ice sheet is "extraordinary" compared to the historical records of the last 350 years.

Background: When it comes to Greenland and sea-level rise, the basics are well known: the air temperature rises and the ice melts from above. The water trickles down through the ice and finally flows into the ocean, where it raises the sea level. At the same time, the glaciers are accelerating their flow into the sea, as the warming of the ocean temperatures eat them away from below.

Yes, but: The big question is – to what extent is the level of surface melting unusual in the summer

Why is it important: By refining the dynamics of sea-level rise, scientists could predict how much damage in Coastal regions of the world is to be expected. It would also help them to determine what to expect from a slowing down of a crucial ocean current that pulls heat from the equator northwards and alters ecosystems and weather patterns.

What they did: The researchers collected and analyzed ice cores from Central West Greenland and a coastal location on the Nuussuaq peninsula in 2015.

  • They were able to determine when the ice melted and thawed, and how often and significantly this over time.
  • These observations give a critical insight into how the ice melt varies with time, as well as the intensity of the melt and how much water drains from the surface. This is the main cause that the ice sheet is losing ground.
  • The co-authors of the study have set a 330-year record of melting, percolating and re-freezing in the western central area of ​​the island as well as a 364-year record of the same variables on the coastal region.

What they found: In recent decades there has been a clear departure d. more melting, water leakage through the ice and freezing every winter.

  • The study showed an increase in melt intensity of 250% -575% in the last 20 years compared to the pre-industrial age.
  • The recent decade has seen a more sustainable and significant melt than any other 10-year period in ice core records.
  • The core records were consistent with computer model simulations and satellite observations of the entire ice sheet. [19659009] The study concludes that the surface darkens as ice melts, absorbs more heat and melts more ice. While this process has been known for a long time, the new study emphasizes its importance, as the surface of the ice surface can be extremely sensitive to seemingly small upward movements at summer air temperatures.

    "Therefore, Greenland is more sensitive to temperature change today than it was just a few decades ago." Warming is more important than ever. "

    The Bottom Line: " This is a climate record that you can easily add up to History book can make – clearly visible [the] fingerprints of the people on the Greenland ice sheet, "says Robin Bell, research professor at the Lamont-Doherty Earth Observatory of Columbia University, opposite Axios. Bell was not involved in the study.


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