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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
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  • 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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Climate change can have an effect on the taste of the wines

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Climate change can have an effect on the taste of the wine
Climate change can have an effect on the taste of the wine. wikimedia commons

New York, Jan 3, 2018: Although winegrowers seem reluctant to try new grape varieties apparently to protect the taste of the wines, new research suggests that they will ultimately have to give up on their old habit as planting lesser-known grape varieties might help vineyards to counteract some of the effects of climate change.

vineyards. wikimedia commons

“It’s going to be very hard, given the amount of warming we’ve already committed to… for many regions to continue growing the exact varieties they’ve grown in the past,” said study co-author Elizabeth Wolkovich, Assistant Professor at Harvard University.

“With continued climate change, certain varieties in certain regions will start to fail — that’s my expectation,” she said.

The study, published in the journal Nature Climate Change, suggests that wine producers now face a choice — proactively experiment with new varieties, or risk suffering the negative consequences of climate change.

“The Old World has a huge diversity of wine grapes — there are overplanted 1,000 varieties — and some of them are better adapted to hotter climates and have higher drought tolerance than the 12 varieties now making up over 80 per cent of the wine market in many countries,” Wolkovich said.

“We should be studying and exploring these varieties to prepare for climate change,” she added.

Unfortunately, Wolkovich said, convincing wine producers to try different grape varieties is difficult at best, and the reason often comes down to the current concept of terroir.

Terroir is the notion that a wine’s flavour is a reflection of where which and how the grapes were grown.

Thus, as currently understood, only certain traditional or existing varieties are part of each terroir, leaving little room for change.

The industry — both in the traditional winegrowing centres of Europe and around the world — faces hurdles when it comes to making changes, Wolkovich said.

In Europe, she said, growers have the advantage of tremendous diversity.

They have more than 1,000 grape varieties to choose from. Yet strict labelling laws have created restrictions on their ability to take advantage of this diversity.

For example, just three varieties of grapes can be labelled as Champagne or four for Burgundy.

Similar restrictions have been enacted in many European regions – all of which force growers to focus on a small handful of grape varieties.

“The more you are locked into what you have to grow, the less room you have to adapt to climate change,” Wolkovich said.

New World winegrowers, meanwhile, must grapple with the opposite problem — while there are few, if any, restrictions on which grape varieties may be grown in a given region, growers have little experience with the diverse — and potentially more climate change adaptable — varieties of grapes found in Europe, the study said.

Just 12 varieties account for more than 80 per cent of the grapes grown in Australian vineyards, Wolkovich said.

More than 75 per cent of all the grapes grown in China is Cabernet Sauvignon — and the chief reason why has to do with consumers.

“They have all the freedom in the world to import new varieties and think about how to make great wines from a grape variety you’ve never heard of, but they’re not doing it because the consumer hasn’t heard of it,” Wolkovich said. (IANS)