Please select your home edition
Edition
Auckland On Water Boat Show

Warm ocean speeds melting of Antarctic glacier

by British Antarctic Survey on 28 Jun 2011
Autosub3 is deployed to go under Pine Island Glacier British Antarctic Survey © http://www.antarctica.ac.uk
New results from an investigation into a large glacier in Antarctica and its impact on global sea level rise are published this week in the journal Nature Geoscience.

An international team of scientists from Lamont-Doherty Earth Observatory and British Antarctic Survey has discovered that due to an increased volume of warm water reaching the cavity beneath Pine Island Glacier in West Antarctica, it’s melting 50 percent faster than it was 15 years earlier. The glacier is currently sliding into the sea at a rate of four kilometres (2.5 miles) a year, while its ice shelf (the part that floats on the ocean) is melting at about 80 cubic kilometres a year.

'More warm water from the deep ocean is entering the cavity beneath the ice shelf, and it is warmest where the ice is thickest,' said lead author, Stan Jacobs, an oceanographer at Columbia University’s Lamont-Doherty Earth Observatory.

In 2009, Jacobs and colleagues sailed to the Amundsen Sea aboard the icebreaking ship Nathaniel B. Palmer to study the region’s thinning ice shelves — floating tongues of ice where land bound glaciers meet the sea. One goal was to study oceanic changes near Pine Island Glacier, which they had visited in an earlier trip in 1994. The researchers discovered that melting beneath the ice shelf had risen by about 50 percent. Although regional ocean temperatures had also warmed slightly, by around 0.2 degrees C, that was not enough to account for the jump.


The local geology offered one explanation. On the same cruise, a group led by Adrian Jenkins, a glaciologist at British Antarctic Survey (BAS) and study co-author, sent an automated submarine called Autosub3 under the ice shelf, which revealed an underwater ridge (mountain) on the sea floor. The team concluded that the ridge had once slowed the glacier like a giant retaining wall. When the receding glacier detached from the ridge, some time before the 1970s, the warm deep water gained access to deeper parts of the glacier. Over time, the inner cavity grew, more warm deep water flowed in, more melt water flowed out, and the ice thinned. With less friction between the ice shelf and seafloor, the landbound glacier behind it accelerated into the sea. Other glaciers in the Amundsen region have also thinned or widened, including Thwaites Glacier and the much larger Getz Ice Shelf.

Dr Adrian Jenkins from British Antarctic Survey said, 'Our research shows that the glacier melt rate has increased significantly because more warm water is circulating beneath it. It appears that the thinning of the ice shelf that has resulted from the higher melt rates is what has allowed the circulation to strengthen. It’s evidence of a complex feedback between glacier dynamics, seabed topography and ocean circulation that we need to understand if we are to say how Pine Island Glacier will evolve in the future.

He added 'The glaciers from the Amundsen Sea region are contributing more to sea level rise than any other part of Antarctica, so it’s imperative we understand the processes involved.'

The study received funding from the US National Science Foundation and the UK National Environment Research British Antartic Survey website

Naiad/Oracle SupplierBakewell-White Yacht DesignAncasta Ker 33 660x82

Related Articles

Zhik sailors win 17 sailing medals at 2016 Olympic Regatta
The 2016 Olympic games are over and what a Games they have been - Zhik sailors dominated Zhik sailors won almost 60% of the medals contested at Rio de Janeiro. It was a regatta which tested sailors and gear - with one day being the most severe conditions ever experienced at an Olympic regatta. For the Zhik team riders on the waters of Rio, four years and more of hard work and dedication have paid off for many.
Posted on 29 Aug
Rio official murdered ten months before the Olympics
Rio de Janeiro is a troubled city and a reeling Olympic host, but it will always have beautiful Guanabara Bay. Does an unsolved murder of an official in Rio in charge of cleaning up Guanabara Bay say a lot about the state of platy in the magical city? Priscilla Pereira was murdered 10 months ago and the thinking is that she was murdered in relation to her work
Posted on 31 Jul
WHO statement on Zika virus
The third meeting of the EC convened by the Director-General under IHR 2005 regarding microcephaly and Zika virus The third meeting of the Emergency Committee (EC) convened by the Director-General under the International Health Regulations (2005) (IHR 2005) regarding microcephaly, other neurological disorders and Zika virus was held by teleconference on 14 June 2016, from 13:00 to 17:15 Central European Time.
Posted on 16 Jun
Atlantic Cup 2016 - a race with an environmental commitment
The Atlantic Cup continues to further its mission for the 2016 race by examining the global economic impact of the ocean The Atlantic Cup continues to further its mission for the 2016 race by examining the global economic impact of the ocean and how an unhealthy ocean can affect the economy.
Posted on 7 Apr
Zika virus situation report
From 1 January 2007 to 16 March 2016, Zika virus transmission was documented in a total of 59 countries and territories. From 1 January 2007 to 16 March 2016, Zika virus transmission was documented in a total of 59 countries and territories. Cuba and Dominica are the latest to report autochthonous (local) transmission of Zika virus on 14 and 15 March, respectively. Five of these countries and territories reported a Zika virus outbreak that is now over.
Posted on 2 Apr
Have Norway scientists solved the Bermuda Triangle mystery?
The Bermuda Triangle has been said to have claimed numerous ships and aircraft over the years The Bermuda Triangle has been said to have claimed numerous ships and aircraft over the years, and everything from aliens to remnants from the lost island of Atlantis have been fingered as the culprits.
Posted on 15 Mar
Cyclone Winston Relief Fund – Help the people of Fiji
Sea Mercy is sending volunteer fleet of small and large vessels, loaded with shelter, food and medical supplies to Fiji. Sea Mercy is once again sending our volunteer fleet of small and large vessels, loaded with shelter, food, water and medical supplies and teams to Fiji.
Posted on 27 Feb
Flying Scot Atlantic Coast Champs - Hanson Medals awarded for rescues
US Sailing Safety at Sea Committee awarded the Arthur B. Hanson Rescue Medals to eight boats for their heroic efforts The US Sailing Safety at Sea Committee awarded the Arthur B. Hanson Rescue Medals to eight boats for their heroic efforts when a microburst storm hit the 2015 Flying Scot Atlantic Coast Championship, hosted by the Blackbeard Sailing Club, in New Bern, NC on September 12.
Posted on 2 Feb
Eco-warriors Sea-Bin crowd sharing critical stage with nine days to go
The automated marina cleaning SeaBin project has raised 86% of their target with 9 days left. The automated marina cleaning SeaBin project has raised $198,020 of $230,000.00 with nine days left on their Indiegogo crowdfunding platform, but they need more help now.
Posted on 29 Dec 2015
Higher levels of Fukushima Cesium detected offshore
Scientists monitoring the spread of radiation in the ocean from the Fukushima nuclear accident report Scientists monitoring the spread of radiation in the ocean from the Fukushima nuclear accident report finding an increased number of sites off the US West Coast showing signs of contamination from Fukushima. This includes the highest detected level to date from a sample collected about 1,600 miles west of San Francisco.
Posted on 6 Dec 2015