Mystery of a massive monolithic iceberg spotted by NASA in Antarctica

A strange gigantic 'monolith' iceberg has been spotted by NASA scientists flying over Antarctica.

The rectangular berg was spotted off the east coast of the Antarctic Peninsula, near the Larsen C ice shelf.

NASA experts believe it may have recently broken off the shelf, and say the sharp angles and flat surfaces are evidence the break occured very recently, Daily Mail reported.

The strange, angular berg is known as a tabular iceberg.

"A tabular iceberg can be seen on the right, floating among sea ice just off of the Larsen C ice shelf," the space agency said.

"The iceberg's sharp angles and flat surface indicate that it probably recently calved from the ice shelf."

The image was taken during an IceBridge flight—an airborne survey of the planet's polar ice that gives a 3D view of the ice that makes up the Arctic and Antarctic, providing vital information on how it changes over time.

In an interview with LiveScience, NASA scientist Kelly Brunt said "tabular icebergs are rather like fingernails that crack off, giving them sharp edges.

"What makes this one a bit unusual is that it looks almost like a square," she said.

She estimated its size to be about a mile wide.

Scientists have been closely tracking Larsen C since a massive iceberg broke free, and began to spin.

Experts had previously said the giant area, estimated to be about the size of Delaware, was locked into place, saying it "likely got stuck on the sea bed"

"But now A68 has started to swing northwards," said Polar oceanographer Mark Brandon recently, who spotted the movement using temperature data collected by the Suomi NPP satellite.

"You can see at between 7-12 July 2018 the weather conditions and ocean currents conspire to swing the trillion tonnes of the giant iceberg A68 in an anticlockwise direction," he said.

"My guess is that A68a will continue rotating as it is now around that western point, until what is currently the northern edge collides with the Larsen C ice front.

"It has a spectacular amount of momentum and it's not going to stopped easily. I should think we will see some interesting collisions with the ice shelf in the next few months."

It is believed a 'temperature anomaly' on 20 July 2018, when it was almost 20 °C warmer than the mean over the Weddell Sea and Larsen Ice shelf, may have triggered the rotation beginning.

Glaciologist and former Project MIDAS collaborator Martin O'Leary told Earther a collision is 'certainly possible' he doubts it would have much of an effect on either the iceberg or shelf given the slow-motion speed at which it would occur.

Eventually, O'Leary says the prevailing ocean currents will push the iceberg northwards and eastwards into the Southern Ocean "where it will probably break up and melt."

Last year it was revealed dense ice cover had so far prevented it from drifting far out to sea.

An animation showing its movement over the last few months reveals how the trillion-plus ton Iceberg A-68 has shifted as it's battered by ocean currents, tides, and winds in the Weddell Sea.

While the huge chunk of ice, estimated to be about the size of Delaware, has moved around some, the experts say its surroundings have kept it somewhat locked into place.

Iceberg A-68 is the sixth largest iceberg on record since scientists began keeping track, and its separation from the ice shelf sparked fears about its future impacts on global sea levels.

Despite all the activity in the Weddell Sea, "its northern end has repeatedly been grounded in shallower water near Bawden Ice Rise," according to Project Midas researchers, who have been monitoring the iceberg over the last year.

"These groundings led eventually to further pieces of the iceberg being shattered off in May 2018.

"Whilst not quite large enough to be given labels themselves, the total area of icebergs lost from A-68 in May was the size of a small city."

Earlier this year, scientists released the first-ever footage of 'A-68', a trillion-ton iceberg the size of Delaware that has broken off from Antarctica.

Stunning aerial clips capture the huge crack in Antarctica's Larsen C ice shelf that led to the third largest iceberg ever recorded breaking off from the continent last July.

When A-68 separated from Larsen C, it revealed an ocean hidden under the ice shelf for 120,000 years, and a team of scientists are now studying the region to uncover some of the hidden ecosystem's mysteries.

Led by the Cambridge-based British Antarctic Survey (BAS), the group will study tiny animals, microbes and plankton on the seafloor to see how they cope with severe changes to their environment.