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Rapid Decay Indicated By Giant Cavity In Antarctic Glaciers

The melting rate on this side of the glacier is extremely high.

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A glacier is shown in a photo taken in Half Moon Bay, Antarctica, Feb. 18, 2018.
A glacier is shown in a photo taken in Half Moon Bay, Antarctica, Feb. 18, 2018. VOA

Scientists from NASA have discovered a gigantic cavity, almost 300 metres tall, growing at the bottom of the Thwaites Glacier in West Antarctica, indicating acceleration in rising global sea levels due to climate change.

The size of the cavity, at Thwaites’ bottom where ocean water could flow in and melt the glacier from below, is big enough to have contained 14 billion tonnes of ice.

Importantly, most of that ice melted over the last three years, the findings showed.

“(The size of) a cavity under a glacier plays an important role in melting,” said lead author Pietro Milillo of NASA’s Jet Propulsion Laboratory (JPL) in California.

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The Collins glacier on King George Island has retreated in the last 10 years and shows signs of fragility, in the Antarctic, Feb. 2, 2018. VOA

“As more heat and water get under the glacier, it melts faster.”

The cavity, reported in the Science Advances journal, was revealed by ice-penetrating radar in NASA’s Operation IceBridge — an airborne campaign beginning in 2010 that studies connections between the polar regions and the global climate.

Thwaites Glacier is currently responsible for approximately 4 per cent of global sea level rise.

It holds enough ice to raise the world’s oceans a little over 2 feet and backstops neighbouring glaciers that would raise sea levels to an additional 8 feet if all the ice were lost.

Antarctica
Antarctica melting away at alarming rate: Study. Flickr

Thwaites is one of the hardest places to reach on Earth, but it is about to become better known than ever before.

The huge cavity was under the main trunk of the glacier on its western side – the side farther from the West Antarctic Peninsula.

In this region, as the tide rises and falls, the grounding line retreats and advances across a zone of about 3 to 5 km. The glacier has been coming unstuck from a ridge in the bedrock at a steady rate of about 0.6 to 0.8 km a year since 1992.

Also Read: Global Greenhouse Gas Level Continues To Rise, Need For a New Political and Investment Paradigm

Despite this stable rate of grounding-line retreat, the melting rate on this side of the glacier is extremely high.

These results highlighted that ice-ocean interactions were more complex than previously understood. (VOA)

Next Story

NASA Cancels First All-Female Spacewalk Due to Lack of Small Spacesuit

"An all-woman spacewalk WILL eventually happen"

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NASA, women, space suit
U.S. astronaut Anne McClain waves before the launch of Soyuz MS-11 space ship at the Russian-leased Baikonur cosmodrome, Kazakhstan, Dec. 3, 2018. VOA

What should have been a giant leap for womankind has turned into a stumble on the path to equality after U.S. space agency NASA canceled the first all-female spacewalk due to a lack of a spacesuit in the right size.

Anne McClain and Christina Koch had been due to step into history books in a spacewalk Friday, during the final week of Women’s History Month.

But McClain will now give up her place on the mission to her male colleague Nick Hague, NASA announced late Monday.

“Mission managers decided to adjust the assignments, due in part to spacesuit availability on the station,” NASA said in a statement.

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FILE – U.S. astronaut Christina Koch attends her final exam at the Gagarin Cosmonauts’ Training Center in Star City outside Moscow, Russia, Feb. 20, 2019. VOA

“McClain learned during her first spacewalk that a medium-size hard upper torso — essentially the shirt of the spacesuit — fits her best. Because only one medium-size torso can be made ready by Friday, March 29, Koch will wear it.”

Nearly 60 years after the first human blasted off into space, less than 11 percent of the 500 plus people who have traveled to space have been women, and spacewalk teams have either been all-male or male-female.

McClain and Koch were both part of the 2013 NASA class that was 50 percent women.

NASA said the decision to change the plan was made in consultation with McClain after a spacewalk last week.

“Anne trained in M and L and thought she could use a large but decided after Friday’s spacewalk a medium fits better,” wrote spokeswoman Stephanie Schierholz on Twitter.

nasa, women, space walk
The NASA announcement was met with disappointment and anger by many following the much-anticipated mission on social media, with some arguing an all-female spacewalk was overdue. Pixabay

“In this case, it’s easier (and faster!) to change spacewalkers than reconfigure the spacesuit.”

The NASA announcement was met with disappointment and anger by many following the much-anticipated mission on social media, with some arguing an all-female spacewalk was overdue.

ALSO READ: Possibilities of UN Banning Killer Robots Looking Growingly Remote

Others said they were sad that a milestone moment on women’s space exploration had been deferred, but safety came first.

“I’m super disappointed about the all-woman spacewalk not happening as scheduled this Friday but I’m also super supportive of astronauts having the authority to say ‘I would be safer using a different piece of equipment’,” wrote Emily Lakdawalla, a senior editor at the U.S. nonprofit The Planetary Society.

“An all-woman spacewalk WILL eventually happen.” (VOA)