NASA spots massive new iceberg three times the size of Manhattan in Antarctica


NASA has spotted a gigantic new iceberg three times the size of Manhattan in Antarctica.

Named B-46, it is believed to measure 66 square nautical miles (87 square miles), according to estimates from the U.S. National Ice Center.

NASA’s Operation IceBridge flight spotted the giant berg, which broke off from Pine Island Glacier in late October.

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A close-up view of the rift separating Pine Island Glacier and iceberg B-46, as seen on an Operation IceBridge flight on November 7, 2018

A close-up view of the rift separating Pine Island Glacier and iceberg B-46, as seen on an Operation IceBridge flight on November 7, 2018

A close-up view of the rift separating Pine Island Glacier and iceberg B-46, as seen on an Operation IceBridge flight on November 7, 2018

Wednesday’s flight plan took the IceBridge team over Pine Island Glacier as part of the long-running campaign to collect year-over-year measurements of sea ice, glaciers, and critical regions of Earth’s ice sheets. 

‘As NASA’s DC-8 flew its pre-determined flight pattern, the new iceberg that calved in late October came into view,’ the Space Agency said.

Ice shelves, floating glacial ice areas that surround much of Antarctica, calve icebergs as part of the natural process of ice flowing out to sea. 

Pine Island Glacier in West Antarctica is known for dispensing icebergs into the Amundsen Sea, but the frequency of such events appears to be on the rise. The Operational Land Imager (OLI) on Landsat 8 acquired the left image of the new iceberg on November 7, 2018. For comparison, the second OLI image shows the same area on September 17, 2018, before a rift quickly propagated across the glacier and spawned the bergs.

Wednesday's flight plan took the IceBridge team over Pine Island Glacier as part of the long-running campaign to collect year-over-year measurements of sea ice, glaciers, and critical regions of Earth's ice sheets.

Wednesday's flight plan took the IceBridge team over Pine Island Glacier as part of the long-running campaign to collect year-over-year measurements of sea ice, glaciers, and critical regions of Earth's ice sheets.

Wednesday’s flight plan took the IceBridge team over Pine Island Glacier as part of the long-running campaign to collect year-over-year measurements of sea ice, glaciers, and critical regions of Earth’s ice sheets.

However, the giant berg may not last long – NASA said ‘satellite imagery and the IceBridge flight showed that the main iceberg is already beginning to break up.’

Scientists are also watching closely to see if the frequency of calving events is changing over time.

The crack that would become B-46 was first noticed in late September 2018 and the iceberg broke away about a month later. 

But in late 2016, IceBridge saw a crack beginning across the ~ approximately 22 mile-wide trunk of Pine Island Glacier. 

It took a year for the rift to fully form and the iceberg named B-44 to break away in September 2017. 

Pine Island has now calved major icebergs in 2013, 2015, 2017, and 2018. 

Prior to that stretch, the glacier was experiencing major calving events about every six years.

Pine Island and nearby Thwaites Glacier alone are contributing about 1 millimeter per decade to global sea level rise, as their flow of ice to the sea has accelerated in recent years, according to NASA research.

It comes a day after NASA revealed a strange rectangular iceberg spotted in the Antarctic was ‘born’ far earlier that thought.

New sea ice forms in a rift created when the B-46 iceberg broke off from Pine Island Glacier.

New sea ice forms in a rift created when the B-46 iceberg broke off from Pine Island Glacier.

New sea ice forms in a rift created when the B-46 iceberg broke off from Pine Island Glacier.

The rectangular iceberg was thought to be freshly calved from Larsen C, which in July 2017 released the massive A68 iceberg, a chunk of ice about the size of the state of Delaware.

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‘The berg was so clean-cut that it was reasonable to assume it might have very recently calved from the Larsen C ice shelf,’ NASA said.

However, new satellite images reveal it ‘has a far more interesting history that thought’ and had actually been floating around the sea for four months before it was spotted.  

THE ANTARCTIC ICE CRISIS

Global sea levels are rising three times faster than a quarter of a century ago because of global warming, a study shows.

Ice losses from Antarctica have increased sea levels by almost 8mm (1/3 inch) since 1992, with two-fifths of this rise coming in the last five years alone.

The finds mean people in coastal communities are at greater risk of losing their homes and becoming so-called climate refugees than previously feared.

They are the result of a major climate assessment known as the Ice Sheet Mass Balance Inter-comparison Exercise (Imbie).

In one of the most complete pictures of Antarctic ice sheet change to date, an international team of 84 experts combined 24 satellite surveys to yield the results.

Study co-leader Professor Andrew Shepherd, of Leeds University, said: ‘We have long suspected that changes in Earth’s climate will affect the polar ice sheets.

 

 

The image below, tweeted November 9, 2018, by Stef Lhermitte of Delft University of Technology, shows the small, newly calved icebergs. The rectangle iceberg—which was about 4 kilometers long at the time appears just north of a curved berg.

WHAT IS A TABULAR ICEBERG? 

Tabular icebergs split off the edges of ice shelves in the same way a fingernail that grows too long ends up cracking off. 

This is why they have sharp edges.

The sharp-angled iceberg that made headlines in late October 2018 had a longer, rougher journey than was initially thought.

The iceberg was spotted on October 16, 2018, during a flight for Operation IceBridge -NASA’s long-running aerial survey of polar ice. 

During that day’s survey of glaciers and ice shelves along the northern Antarctic Peninsula, scientist Jeremy Harbeck spotted the compelling berg.

Not only were the edges of the iceberg extremely straight, but the two corners appeared ‘squared off’ at right angles.  

Scientists used images from Landsat 8 and the European Space Agency’s Sentinel-1 to trace the berg back to its origins. 

The original 'monolith'rectangular berg was spotted near the Larsen C ice shelf, and NASA experts believe it the sharp edges are evidence it may have recently broken off the shelf

The original 'monolith'rectangular berg was spotted near the Larsen C ice shelf, and NASA experts believe it the sharp edges are evidence it may have recently broken off the shelf

The original ‘monolith’rectangular berg was spotted near the Larsen C ice shelf, and NASA experts believe it the sharp edges are evidence it may have recently broken off the shelf

They found that it actually calved from the ice shelf’s new front in early November 2017, just a few months after A-68 broke away.   

The rectangle berg then began a northward journey, navigating the newly open water between the Larsen C ice shelf and Iceberg A-68. 

Collision threats were everywhere: A-68 could smash into the little bergs at any time, and smaller bergs could collide with each other.

THE RECTANGULAR BERG’S INCREDIBLE JOURNEY

It calved from the ice shelf’s new front in early November 2017, just a few months after A-68 broke away.   

The rectangle berg then began a northward journey, navigating the newly open water between the Larsen C ice shelf and Iceberg A-68. 

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Collision threats were everywhere: A-68 could smash into the little bergs at any time, and smaller bergs could collide with each other.

The berg cruised all the way north and through a narrow passage between the A-68’s northern tip and a rocky outcrop near the ice shelf known as Bawden Ice Rise. NASA/UMBC glaciologist Chris Shuman likens this zone to a nutcracker. 

An area of geometric ice rubble is visible in the Landsat 8 image  from October 14, 2018, two days before the IceBridge flight. A-68 has repeatedly smashed against the rise and caused pieces of ice to splinter into clean-cut geometric shapes. The once-long rectangle berg did not make it through unscathed; it broke into smaller bits. The iceberg in Harbeck’s photograph, circled in the annotated Landsat 8 satellite image, appears closer to the shape of a trapezoid. The trapezoidal berg is about 900 meters wide and 1500 meters long, which is tiny compared to the Delaware-sized A-68.

An area of geometric ice rubble is visible in the Landsat 8 image  from October 14, 2018, two days before the IceBridge flight. A-68 has repeatedly smashed against the rise and caused pieces of ice to splinter into clean-cut geometric shapes. The once-long rectangle berg did not make it through unscathed; it broke into smaller bits. The iceberg in Harbeck’s photograph, circled in the annotated Landsat 8 satellite image, appears closer to the shape of a trapezoid. The trapezoidal berg is about 900 meters wide and 1500 meters long, which is tiny compared to the Delaware-sized A-68.

An area of geometric ice rubble is visible in the Landsat 8 image from October 14, 2018, two days before the IceBridge flight. A-68 has repeatedly smashed against the rise and caused pieces of ice to splinter into clean-cut geometric shapes. The once-long rectangle berg did not make it through unscathed; it broke into smaller bits. The iceberg in Harbeck’s photograph, circled in the annotated Landsat 8 satellite image, appears closer to the shape of a trapezoid. The trapezoidal berg is about 900 meters wide and 1500 meters long, which is tiny compared to the Delaware-sized A-68.

A-68 has repeatedly smashed against the rise and caused pieces of ice to splinter into clean-cut geometric shapes. 

An area of geometric ice rubble is visible in the Landsat 8 image from October 14, 2018, two days before the IceBridge flight.

The once-long rectangle berg did not make it through unscathed; it broke into smaller bits. 

The iceberg in Harbeck’s photograph, circled in the annotated Landsat 8 satellite image, appears closer to the shape of a trapezoid. 

The trapezoidal berg is about 900 meters wide and 1500 meters long, which is tiny compared to the Delaware-sized A-68.

By November 2018 the iceberg had moved out of the rubble zone and into open water. 

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The berg cruised all the way north and through a narrow passage between the A-68’s northern tip and a rocky outcrop near the ice shelf known as Bawden Ice Rise. NASA/UMBC glaciologist Chris Shuman likens this zone to a nutcracker. 

A-68 has repeatedly smashed against the rise and caused pieces of ice to splinter into clean-cut geometric shapes. 

An area of geometric ice rubble is visible in the Landsat 8 image from October 14, 2018, two days before the IceBridge flight.

The once-long rectangle berg did not make it through unscathed; it broke into smaller bits. 

The iceberg in Harbeck’s photograph, circled in the annotated Landsat 8 satellite image, appears closer to the shape of a trapezoid. 

The trapezoidal berg is about 900 meters wide and 1500 meters long, which is tiny compared to the Delaware-sized A-68.

By November 2018 the iceberg had moved out of the rubble zone and into open water. 

Shuman said: ‘Now it’s just another iceberg on its way to die.’

A second rectangular berg, known as a ‘tabular’ iceberg, was spotted off the east coast of the Antarctic Peninsula, near the Larsen C ice shelf and close to the first one.

It is part of a large ‘field of bergs NASA experts may have recently broken off the shelf, and say the sharp angles and flat surfaces are evidence the break occurred very recently. 

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.

‘I thought it was pretty interesting; I often see icebergs with relatively straight edges, but I’ve not really seen one before with two corners at such right angles like this one had,’ said IceBridge senior support scientist Jeremy Harbeck. 

The rectangular iceberg appeared to be freshly calved from Larsen C, which in July 2017 released the massive A68 iceberg, a chunk of ice about the size of the state of Delaware.

In a different photo (above), Harbeck captured both the edge of the now-famous iceberg, and a slightly less rectangular iceberg. That image also captures A68 in the distance.

‘I was actually more interested in capturing the A68 iceberg that we were about to fly over, but I thought this rectangular iceberg was visually interesting and fairly photogenic, so on a lark, I just took a couple photos,’ Harbeck said.

The flight originated from Punta Arenas, Chile, as part of a five-week-long IceBridge deployment, which began Oct. 10 and is scheduled to conclude Nov. 18.

The scheme is NASA’s longest-running aerial survey of polar ice.

During the survey, designed to assess changes in the ice height of several glaciers draining into the Larsen A, B and C embayments, IceBridge senior support scientist Jeremy Harbeck spotted a very sharp-angled, tabular iceberg floating among sea ice just off of the Larsen C ice shelf. 

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

The flight saw a 'field' of large tabular icebergs located between Antarctica's Larsen C ice shelf and the A-68 ice island, which calved off of the Larsen C last year, as seen on a NASA Operation IceBridge mission

The flight saw a 'field' of large tabular icebergs located between Antarctica's Larsen C ice shelf and the A-68 ice island, which calved off of the Larsen C last year, as seen on a NASA Operation IceBridge mission

The flight saw a ‘field’ of large tabular icebergs located between Antarctica’s Larsen C ice shelf and the A-68 ice island, which calved off of the Larsen C last year, as seen on a NASA Operation IceBridge mission

This panorama of the entire first tabular iceberg was edited together from two images taken while flying past the berg

This panorama of the entire first tabular iceberg was edited together from two images taken while flying past the berg

This panorama of the entire first tabular iceberg was edited together from two images taken while flying past the berg

‘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.’

In an interview with LiveScience, NASA scientist Kelly Brunt said ‘tabular icebergs are rather like fingernails that crack of, 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. 



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