What's up with this bizarre rectangular iceberg? : NPR

An iceberg recently spotted by NASA scientists seems to have been carefully cut into a perfect rectangle. It arouses a lot of attention because of its unexpected angles and its straight lines.

It's nothing like the craggy and uneven mass that sank the Titanic, perhaps the most famous iceberg of all time.

But in fact, there are few particularly unusual things in the photographed iceberg floating near the Larsen C ice floe in Antarctica, as explained by the ice floe specialist, Alek Petty. He is a research scientist with Operation IceBridge of NASA, the group that took the great photo, and is based at NASA's Goddard Space Flight Center.

He says it's a kind of training called tabular iceberg. They form in Antarctica, he says, "where we have these very large floating ice platforms connected to the earth". The ice is "somehow scattered in this very thin layer," says Petty, and "because it's ice that's brittle, if it gets too weak or if it comes in contact with anything else, she can break and break a bit. "

Petty likens the process to a nail that grows and grows, "then it becomes very weak because actually the ice somehow expands into the ocean," leaving less support for floating ice. At that time, tides or strong winds could break the icebergs.

According to NASA, this iceberg was probably recently separated from the pack ice. And the portion above the surface probably accounts for only 10% of the total iceberg, Petty said.

But why such straight lines? Petty likens this to a broken glass plate – the lines are usually very straight. "You can just get those fracture lines that can form these interesting geometric structures," he says, pointing out another, iceberg shaped triangle spotted by NASA scientists recently.

According to Mr. Petty, the rectangular iceberg has a width of about one mile – considerably smaller than another well known iceberg from the Larsen C ice floe. After years of anticipating the On the part of scientists, a Delaware – sized formation was separated from Antarctica last year. Geoff Brumfiel of NPR reported that this iceberg was approximately 2,300 square miles.

NASA's IceBridge operation, which monitors polar ice with aircraft readings, has been going on for a decade. But this is the first year that scientists are also studying Antarctica using the new Ice-2 satellite, Cloud and Elevation Satellite.

"IceBridge and ICESat-2 both use laser altimeters that emit light pulses to the ground and measure the time it takes for this light to bounce off the ice and back to the instrument's sensors," NASA said. Beginning of the month. "Scientists can then calculate the distance between the plane or satellite and the surface of the ice, which gives them the height of the ice."