Pine Island Glacier Antarctica iceberg
© Stef Lhermitte/Twitterhuge iceberg four times the size of Manhattan (pictured) has broken off of an Antarctic glacier. The calving is the second time in just two years that a massive iceberg has separated from the continent's Pine Island Glacier
A huge iceberg four times the size of Manhattan has broken off of an Antarctic glacier. The calving is the second time in two years that a massive iceberg has separated from the continent's Pine Island Glacier. One scientist has claimed the ice chunk shows the glacier is 'falling to pieces'.

The new break-off, which measures 103-square-mile (266 sq km), follows the release of an iceberg the size of Delaware from Antarctica's Larsen C ice shelf in July.

Warming waters around the continent may be melting the enormous ice blocks from underneath, causing them to break free.

Experts say the location from which the iceberg broke off is of particular interest. Most of the time, icebergs break free from glaciers around the edges, but this most recent departure - from western Antarctica's Pine Island Glacier - has stemmed from an interior section. This is unusual, and is not the first time the glacier has exhibited this behaviour in recent years, with a 224-square-mile (580 sq km) interior segment breaking off in 2015. Experts claim it could be the result of warming ocean waters melting the ice from below, destabilising it.

Satellite observation specialist Dr Stef Lhermitte, from Delft University of Technology in the Netherlands, first reported the new iceberg on Twitter. He said the glacier's latest break-off is the fifth biggest Antarctic calving event since 2000.

He tweeted: 'Breaking news from Pine Island Glacier, which lost 267km2 of icebergs today, after the internal crack resulted in a large calving event

Expert Stef Lhermitte took to Twitter to report the huge calving. He posted an animation showing how the area has progressed since 2013, including the calving og another huge iceberg from the region in 2015

The expert added that satellite imagery 'shows the Pine Island glacier calving clearly and seems to indicate that the iceberg is falling in pieces.' Recent ice chunks have broken away from a floating part of the glacier, meaning they do not directly contribute to sea level rises.

The loss of these barriers could see land ice break away from the continent, resulting in irreversible changes to Earth's oceans. Pine Island Glacier could raise sea levels by 1.7 feet (0.5 metres) if allowed to completely melt, the Washington Post reports.
pine island glacier antarctica
© MailOnlineThe Pine Island Glacier, found in western Antarctica, has been losing ice at an accelerating rate over the past four decades.
Another iceberg the size of Delaware broke free from Antarctica's Larsen C ice shelf in July.

Last week an international agreement was put in place to protect the area of ocean left exposed.
iceberg Larson-C
© Deimos ImagingIn July, an iceberg broke free from the Larsen C ice shelf. An international agreement is in place to protect the area of ocean left exposed. The iceberg- called A68 - is starting to move North, and will leave behind a 5,818 square kilometer area exposed to open marine conditions
The iceberg- called A68 - is starting to move North, and will leave behind a 2,246-square-mile (5,818 sq km) area of seabed exposed to open marine conditions. Much of the protected area may have been covered in ice since the last inter-glacial period around 120,000 years ago, so the site presents itself as a unique opportunity for scientists to study how marine life responds to this dramatic change.

The protected area is the first to benefit from an international agreement in 2016 by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR). It allows research to be undertaken in the area, without any impact from commercial fishing, to address questions relating to how biological communities develop over time, and how new species colonise previously ice-covered areas.