The London-sized chunk of ice that broke off Antarctica and why it’s interesting to science

A large iceberg measuring about 1270 square kilometers, roughly the size of the London metropolitan area, has broken off from Antarctica.

This Friday, detection instruments on the surface of the Brunt Ice Shelf confirmed the separation.

Nearby, the British Antarctic Survey (BAS), a British institution dedicated to Antarctic research, operates the Halley station. Since 2017, it has been doing so with reduced capacity due to the looming prospect of a landslide.

There is currently no one on the base, so there is no risk to human life.

BAS has a variety of GPS devices on the Brunt Platform that transmit information about ice movements to the agency’s headquarters in Cambridge.

Experts will inspect satellite images of what happened when they become available.

They will want to verify that unexpected instabilities do not appear on the remaining ice shelf where Halley Station is located.

“Even if the breaking of large chunks of the Antarctic ice shelves is quite normal of their operation, large landslides like the one detected on the Brunt ice floe on Friday are still quite rare and exciting ”, declared the professor Adrian Luckman, who tracked satellite imagery from the Brunt over the past few weeks and predicted the breakout.

“With three long cracks that have actively developed in the Brunt platform system over the past five years, we all anticipated that something spectacular was going to happen,” he told the BBC.

“Time will tell if this detachment will cause more parts to break in the days and weeks to come.” At Swansea University, we are studying the development of sea ice cracks, because while some lead to large landslides, others do not; and the reasons for this may explain why large ice shelves exist, ”he added.

Where exactly did the breakup occur?

The detachment detected this Friday is on the Brunt Ice Pack, which is the floating bulge of glaciers that have sunk from the land into the Weddell Sea.

On a map, the Weddell Sea is that section of Antarctica directly south of the Atlantic Ocean. The Brunt is on the east side of the sea.

As with all ice shelves, icebergs break off periodically. The last big chunk to break in this area dates back to the early 1970s.

How big is the new iceberg?

It is estimated to measure approximately 1,270 square kilometers. It’s big in every way, but not as big as the A68 iceberg that broke off the Larsen C ice shelf in July 2017 on the west side of the Weddell Sea.

But even with a quarter the size of the A68 this Brunt block will have to be followed due to the future risk it could represent for navigation.

The US National Ice Center will name the new detachment in due course. Since it is in the same Antarctic quadrant (0-90W) that the A68 originated from, it will also have the letter “A” in its name. It is probably called A74.

Is this a consequence of climate change?

No. Ice blocks on the leading edge of an ice shelf are a very natural behavior.

The platform tends to balance and iceberg expulsion is a way to balance the accumulation of masses derived from snowfall and the influx of more ice from the glaciers that feed on the land.

Unlike the Antarctic Peninsula, across the Weddell Sea, scientists have not detected any climate changes in the Brunt region that would significantly alter the natural process described above.

Further, estimates suggest that the Brunt had peaked in the past 100 years when this detachment occurred. This break was long overdue.

BBC Mundo