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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)

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NASA: Sending Back Astronauts to Moon in 2024 Could Cost About $30 Billion

The entire project will be framed as a practice run for a future mission to Mars

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NASA, which has dubbed its current lunar programme Artemis (after Apollo's twin sister, the Greek goddess of the hunt, the wilderness and the moon), plans to send one male and one female astronaut to the moon in 2024. VOA

Returning astronauts to the moon in 2024 could cost about $30 billion, or roughly the same price tag as the Apollo 11 spaceflight when factoring in inflation, NASA has said.

“For the whole programme, to get a sustainable presence on the moon, we’re looking at between $20 and $30 billion,” NASA Administrator Jim Bridenstine said in a TV interview on Friday, though noting that that figure does not include money already spent on the rocket and space capsule the agency plans to use for the programme, Efe news reported.

The total cost of the Apollo programme that the US launched in 1961 and concluded in 1972 was $25 billion. The climax of that programme came nearly 50 years ago when two astronauts landed on the moon as part of the Apollo 11 mission, which cost $6 billion at the time, equivalent to $30 billion today.

nasa, moon
Then one male astronaut and – for the first time – a female astronaut would set foot on the lunar surface in 2024. Pixabay

NASA, which has dubbed its current lunar programme Artemis (after Apollo’s twin sister, the Greek goddess of the hunt, the wilderness and the moon), plans to send one male and one female astronaut to the moon in 2024.

Bridenstine recalled that the main difference between the Apollo programme and the Artemis program is that the former culminated with brief stays on the moon while the latter will entail a permanent human presence there.

The plan will involve the recruitment of private companies and international partners, the construction of a lunar space station and manned landings at the moon’s south pole within five years.

NASA, moon
That rocket will send into orbit a new spacecraft known as Orion, whose lead contractor is Lockheed Martin. VOA

The entire project will be framed as a practice run for a future mission to Mars. The programme includes an unmanned mission around the moon in 2020 and a manned mission that also will orbit the moon two years later. Then one male astronaut and – for the first time – a female astronaut would set foot on the lunar surface in 2024.

ALSO READ: NASA’s Mars 2020 Rover, Latest Robotic Mission to Explore Ancient Life on Red Planet

The three lunar missions will be delivered into space by the Space Launch System, a rocket being developed by NASA and Boeing that will be the largest ever built once it is fully assembled. That rocket will send into orbit a new spacecraft known as Orion, whose lead contractor is Lockheed Martin.

Besides these missions exclusively handled by NASA, five other launches will be carried out to place in lunar orbit the components for construction of the Gateway mini-space station, which will serve as a staging post for moon landings. Those five missions between 2022 and 2024 will be operated by private companies, according to NASA’s plans. (IANS)