A cavity two thirds the size of Manhattan has formed under one of the world’s most dangerous glaciers
The Thwaites Glacier is one of the most
dangerous glaciers in the world, and scientists are eager to travel to
Antarctica to study it.
NASA researchers released a study in January that
said a giant cavity roughly two-thirds the size of Manhattan was
rapidly melting underneath the glacier due to climate change. The cavity
is big enough to have contained 14 billion tons of ice, with most of
it melting over the last three years.
Even before
this cavity, Thwaites' rapid ice loss and potential impact on global sea
levels was significant enough that researchers from around the world
planned to physically travel there starting this year.
Only 28 people have ever set foot on the glacier, according to Britain's Natural Environmental Research Council, or NERC.
So what might happen if Thwaites does collapse?
"It
could potentially destabilize the whole region of west Antarctica,"
Lucas Zoet, a University of Wisconsin geoscientist, , told USA TODAY.
The
glacier sits in west Antarctica and flows into the Amundsen Sea.
Roughly the size of Florida, Thwaites' melting is currently responsible
for about four percent of global sea level rise, according to NASA in
its recent study on the glacier's giant hole.
"It's a major throughway of how ice gets discharged from west Antarctica into the ocean," said Zoet.
Thwaites
has been difficult to study because it's far from U.S. bases in the
Antarctic and also because the weather is "particularly bad," said Zoet.
The glacier measures more than 70,000 square miles, making it one of the largest glaciers in the world, said NERC.
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| A map of where Thwaites is located. (Photo11: USA TODAY) |
The glacier's grounding line, the point at which ice
meets the land underneath, has retreated over 9 miles between 1992 and
2011, according to NERC. As ice and warmer sea water flow underneath the
glacier, it lifts off the land and speeds up its retreat.
"If
this cavity grows or sort of expands, that’s one way it can get off
this last sort of ridge that Thwaites Glacier is hanging on to," Zoet
told USA TODAY.
What especially worries scientists
is if the melting accelerates. If all the ice on Thwaites is lost, it
would raise ocean levels another two feet, according to the NASA study.
But the glacier also backstops neighboring glaciers. If those glaciers
also melt, sea levels could rise an additional eight feet, researchers
warn. "It
holds a kind of wildcard for being able to increase the rate of
sea-level rise quite rapidly if things unfold a certain way," said Ted
Scambos, a senior research scientist with the National Snow and Ice Data
Center.
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| Thwaites Glacier |
How do you visit a location so remote?
Scambos
said research into Thwaites' retreat started as early as the 1990s, as
satellite data got better at tracking Antarctic ice sheets.
Scambos is part of the International Thwaites Glacier Collaboration (ITGC), a partnership between British and American scientists that studies the glacier's retreat up close.
"Satellites
show the Thwaites region is changing rapidly, but to answer the key
questions of how much, and how quickly sea-level will change in the
future, requires scientists on the ground with sophisticated equipment
collecting the data we need to measure rates of ice-volume, or ice-mass
change," said William E. Easterling, assistant director for the National
Science Foundation’s Geosciences Directorate, in a statement last year.
"The
point is not so much is whether or not it’s going to happen, unless we
really change how much heat-trapping gasses we’re putting in the
atmosphere," said Scambos of the glacier's melting. "Eventually, we’re
going to lose big areas of the Antarctic, big areas in Greenland. The
important thing is how fast is this going to happen."
Melting
from Greenland and Antarctica would not only bump up sea levels, but
might bring more extreme weather and dramatic shifts in temperature, according to a study published in Nature in February.
Scambos
said coastal cities in the U.S. and worldwide are looking ahead to how
higher sea levels could impact them. If Thwaites' melting happens over
centuries, then nations would have more time to get ready.
A faster rise in sea level, however, could force countries to act more urgently.
If
that pace were to double or triple suddenly because glacier melt really
picked up, "then that’s going to really throw a wrench into the ability
for these nations to plan and prepare for the impacts of sea-level
rise," Scambos said.
Links
- Melting ice from Greenland and Antarctica could cause more extreme weather
- Here are the facts: Despite winter storms, global warming is real
- Melting glaciers in Arctic reveal land hidden for 40,000 years, study says
- Antarctic ice melting 6 times faster than it did in '80s
- Ancient Antarctic ice sheet collapse could happen again, triggering a new global flood
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