Manhattan-sized hole opens up under Antarctic glacier

A massive cavity so large you could fit New York City inside of it has opened up under Thwaites glacier in Antarctica. Scientists say if it collapses, as it's likely to do within the next 50 to 100 years, it could cause a catastrophic rise in sea levels capable of flood coastal cities around the world.

The researchers behind the discovery describe what it means in a paper published Jan. 30 in the journal Science Advances. They expected to find that much ice had been lost, but were shocked by the size of the growing void.

timeline is 50-100 years based on projections—which is not a long time!!!! https://t.co/LzokvhPjLE
— Dave Gershgorn (@davegershgorn) February 5, 2019

From Denise Chow at NBC News:
Scientists have discovered an enormous void under an Antarctic glacier, sparking concern that the ice sheet is melting faster than anyone had realized — and spotlighting the dire threat posed by rising seas to coastal cities around the world, including New York City and Miami.
The cavity under Thwaites Glacier in West Antarctica is about six miles long and 1,000 feet deep — representing the loss of 14 billion tons of ice.
It was discovered after an analysis of data collected by Italian and German satellites, as well as NASA’s Operation IceBridge, a program in which aircraft equipped with ice-penetrating radar fly over polar regions to study the terrain.

Read the rest of the piece here.
GIF below: Sinking areas at Thwaites Glacier are shown here in red and rising areas in blue. The growing cavity (red mass, center) caused the greatest sinking. [GIF credit: NASA/JPL-Caltech]

[via. Thwaites Glacier in West Antarctica. NASA/OIB/Jeremy Harbeck]