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The connection between Antarctic Volcanic Eruptions and abrupt Climate Change: Study

Joseph McConnell conducted the study

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The connection between Antarctic Volcanic Eruptions and abrupt Climate Change
The connection between Antarctic Volcanic Eruptions and abrupt Climate Change. Pixabay
  • The Climate change that began approximately 17,700 years ago included a sudden poleward shift in the westerly winds encircling Antarctica
  • Joseph McConnell’s ice core laboratory enabled high-resolution measurements of ice cores extracted from remote regions of the Earth, such as Greenland and Antarctica
  • West Antarctic Ice Sheet Divide core was drilled to a depth of more than 3,405 meters

New York, USA, September 7, 2017: A series of volcanic eruptions in the Antarctica coincided with increased deglaciation and rise in global greenhouse gas concentrations about 17,700 years ago, says a study.

“Detailed chemical measurements in Antarctic ice cores show that massive, halogen-rich eruptions from the West Antarctic Mt. Takahe volcano coincided exactly with the onset of the most rapid, widespread Climate Change in the Southern Hemisphere during the end of the last ice age,” said Joseph McConnell, Professor at the Desert Research Institute (DRI) in Nevada, US.

The Climate Change that began approximately 17,700 years ago included a sudden poleward shift in the westerly winds encircling Antarctica with corresponding changes in sea ice extent, ocean circulation and ventilation of the deep ocean.

Evidence of Climate Change like this is found in many parts of the Southern Hemisphere and in different paleoclimate archives, but what prompted these changes has remained largely unexplained.

“We postulate that these halogen-rich eruptions created a stratospheric ozone hole over Antarctica that, analogous to the modern ozone hole, led to large-scale changes in atmospheric circulation and hydro climate throughout the Southern Hemisphere,” McConnell said.

Furthermore, the fallout from these eruptions – containing elevated levels of hydrofluoric acid and toxic heavy metals – extended at least 2,800 kilometers from Mt. Takahe and likely reached southern South America.

For the study, McConnell’s ice core laboratory enabled high-resolution measurements of ice cores extracted from remote regions of the Earth, such as Greenland and Antarctica.

One such ice core, known as the West Antarctic Ice Sheet Divide (WAIS Divide) core was drilled to a depth of more than 3,405 meters, and much of it was analyzed in the Desert Research Institute Ultra-Trace Laboratory for more than 30 different elements and chemical species.

Additional analyses and modeling studies critical to support the authors’ findings were made by collaborating institutions around the US and the world.

“These precise, high-resolution records illustrate that the chemical anomaly observed in the WAIS Divide ice core was the result of a series of eruptions of Mt. Takahe located 350 kilometers to the north,” Monica Arienzo, Assistant Research Professor at DRI, said. (IANS)

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Rising Global Warming Temperatures Could Make Greenland Sand Exporter

The study said that sand and gravel might also be used in the future to reinforce beaches and coastlines.

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FILE - The Greenland ice sheet is seen in southeastern Greenland, Aug. 3, 2017. VOA

Greenland could start to export sand in a rare positive spinoff from global warming that is melting the island’s vast ice sheet and washing large amounts of sediment into the sea, scientists said Monday.

Mining of sand and gravel, widely used in the construction industry, could boost the economy for Greenland’s 56,000 population who have wide powers of self-rule within Denmark but rely heavily on subsidies from Copenhagen.

By mining sand, “Greenland could benefit from the challenges brought by climate change,” a team of scientists in Denmark and the United States wrote in the journal Nature Sustainability.

The study, headlined “Promises and perils of sand exploitation in Greenland,” said the Arctic island would have to assess risks of coastal mining, especially to fisheries.

Rising global temperatures are melting the Greenland ice sheet, which locks up enough water to raise global sea levels by about seven meters (23 ft) if it ever all thawed, and carrying ever more sand and gravel into coastal fjords.

Greenland
FILE – A man walks to his boat past a number of abandoned and dry-docked boats in the town of Tasiilaq, Greenland, June 15, 2018. VOA

“You can think of it [the melting ice] as a tap that pours out sediment to the coast,” said lead author Mette Bendixen, a researcher at the University of Colorado’s Institute of Arctic and Alpine Research.

Worldwide demand for sand totaled about 9.55 billion tons in 2017 with a market value of $99.5 billion and is projected to reach almost $481 billion in 2100, driven by rising demand and likely shortages, the study said.

That meant a rare opportunity for the island.

“Normally the Arctic peoples are among those who really feel climate change — the eroding coast, less permafrost,” said Bendixen. “This is a unique situation because of the melting ice sheet.”

David Boertmann of Aarhus University, who was not involved in the study, said there was already some local mining of sand for the domestic construction industry in Greenland.

Drawbacks for Greenland, common to other mining projects on the island ranging from uranium to rare earth minerals, include the distance to markets in Europe and North America, he said.

Still, Bendixen said sand was already often transported long distances, such as to Los Angeles from Vancouver or from Australia to Dubai.

ALSO READ: Excavations in Egypt’s Sinai Helped Archaeologists Discover Ancient Workshop

The study said that sand and gravel might also be used in the future to reinforce beaches and coastlines. The study said that sand and gravel might also be used in the future to reinforce beaches and coastlines

“At the moment it is an inexpensive resource, but it will become more expensive,” she said.

The study said that sand and gravel might also be used in the future to reinforce beaches and coastlines at risk of rising sea levels, caused in part by Greenland’s thaw. (VOA)