NASA Earth Observation: Pine Island Glacier

This combination of Dec. 10, 2013, left, and March 11, 2014 photos provided by NASA Earth Observation, shows a large iceberg separating from the Pine Island Glacier and traveling across Pine Island Bay in Antarctica. 

Scientists are watching the iceberg, which is bigger than the island of Guam, as it slowly moves away from the glacier, bottom right in December, upper left center in March. 

NASA Earth Observation scientist Kelly Brunt said it is more a wonder than a worry and is not a threat to shipping or sea level rise. 

AP Photo /NASA Earth Observation

Brunt said the iceberg, named B-31, is about 255 square miles (660 million sq. kilometers), roughly six times as big as Manhattan and as much as 1,600 feet (487 meters) thick.

It broke off from the critical Pine Island Glacier last fall and researchers have been watching it move away ever since.

She said it is completely natural for icebergs to split off from glaciers in Antarctica, however this calving does shrink the Pine Island Glacier beyond its 30-year normal.

Antarctic iSTAR mission: First leg at Pine Island Glacier accomplished

Dr Stephen Cornford calibrating his instruments in the field. 

Credit: David Vaughan

The iSTAR science programme brings together multi-disciplinary teams to investigate ice loss from Pine Island Glacier, the biggest single contributor to worldwide sea level rise.

The next step of the programme, an ocean investigation, is now underway.

Launched last November, iSTAR is an ambitious scientific programme, funded by the Natural Environment Research Council (NERC), uniting leading scientists from 11 UK universities and from British Antarctic Survey (BAS).

Using state-of-the-art technologies to measure changes to the flow and thickness of glaciers, and to investigate the role that the ocean plays in transporting warm water beneath ice shelves, this multi-disciplinary mission is the first of its kind for the UK.

Scientists recognise the urgent need to understand the causes and impact of recent rapid ice loss from Pine Island Glacier.

The impact on global sea-level rise could be significant – this mission is designed to find out just how significant.

This new knowledge about its stability is critical for making better predictions about how the ocean and ice will respond to future environmental change.

The team travelled 1,500km (932 miles) by 'tractor train' across the glacier ice, taking samples and measurements as they went.

This is the first time in recent British history that this method of crossing the ice has been undertaken.

Sophisticated equipment, supplies and fuel were loaded on to specially designed rubber mats and towed by huge tractors.

A 'caboose' (a caravan-like office and living space) housed technical equipment and provided a warm space for the science team to plan their days' work.

A pisten bully towing the caboose, equipment and fuel from one campsite to another. 

Credit: Damon Davies

Programme lead Dr Andy Smith from British Antarctic Survey said: "The ice-traverse has been a huge success. We visited all the proposed sites on the route, conducted considerably more experiments than had been originally planned and completed much quicker than expected."

"Our success has been thanks to the excellent support we have received, the sheer hard work and dedication of all the traverse members and some good luck with the weather."

"We are very pleased to have successfully completed this year's deep-field work."

This next leg of the mission will focus on retrieving moorings, tagging seals, and performing further measurements using an Autosub (autonomous submarine) operated by the National Oceanography Centre (NOC), ocean gliders, and onboard instrumentation to analyse how much the ocean is contributing to the retreat of Pine Island Glacier from below the ice shelf.

The ship will be deployed in Pine Island Bay until early March.

NOC's Autosub3 is ready to launch in front of the Pine Island Glacier in the Western Antarctic. 

In a mission lasting 36 hours it ran 60km under the ice shelf, into a cave, topped with ice up to 1000 m thick.

MODIS Image: Pine Island Glacier 2013

This MODIS image taken by NASA’s Aqua satellite on Nov. 10, 2013, shows an iceberg that was part of the Pine Island Glacier and is now separating from the Antarctica continent.

What appears to be a connection point on the top left portion of the iceberg is actually ice debris floating in the water.

The original rift that formed the iceberg was first observed in October 2011 but as the disconnection was not complete, the “birth” of the iceberg had not yet happened.

It is believed the physical separation took place on or about July 10, 2013, however the iceberg persisted in the region, adjacent to the front of the glacier.

The iceberg is estimated to be 21 miles by 12 miles (35 km by 20 km) in size, roughly the size of Singapore. 

A team of scientists from UK's Sheffield and Southampton universities will track it and try to predict its path using satellite data.

Image credit: NASA