Greenlandic glacier melting faster than expected

Greenlandic glacier melting faster than expected

An international team of scientists has discovered that warming in the Arctic region has triggered the accelerated melting of a Greenlandic glacier. Presented in The Cryosphere journal, the findings reveal that the overall mass loss of the Mittivakkat Glacier for 2011 has amounted to 2.45 metres, 0.29 metres higher than what was recorded in 2010. The study was funded in part by the INTERACT ('International network for terrestrial research and monitoring in the Arctic') project, which has clinched EUR 7.3 million under Research Infrastructures of the EU's Seventh Framework Programme (FP7).

Mittivakkat Glacier © University of Sheffield

Researchers say there are two record losses in mass observations for the Mittivakkat Glacier, the longest observed glacier in Greenland, for two consecutive years. They add that the value for 2011 was also higher than the 16-year average observed loss of 0.97 metres per year.

The observations for the current year also show how 2011 is a record-breaking glacier mass loss year. This is the result even after comparisons were made between the mass balance value against simulated glacier mass balance values back to 1898.

Scientists have been assessing the Mittivakkat Glacier for mass balance and glacier front fluctuations since 1995 and 1931 respectively. In this year alone, the glacier terminus has retreated some 22 metres. This figure is 12 metres less than the 34 metres observed the year before, and around 1 300 metres in total since the first photographic observations in 1931.

The researchers from Denmark, the United Kingdom and the United States propose that the mass losses of the glacier are triggered by higher surface temperatures and low precipitation. These losses are representative of the wider region which contains hundreds of local glaciers in Greenland. The team says other Greenlandic glaciers are showing terminus retreats that are just about as big as the one Mittivakkat Glacier is sustaining.

They say local glacier observations in Greenland are not common. The Mittivakkat Glacier is the only glacier in Greenland for which long-term observations of both the surface mass balance and glacier front fluctuations exist, according to the researchers.

The Mittivakkat Glacier has not only been dealing with higher temperatures, but it has been receiving less snow as well. The glacier has recorded a negative surface mass balance in the last 14 of 16 years.

Commenting on the results, Dr Edward Hanna of the University of Sheffield in the United Kingdom, the principal investigator on the fieldwork carried out over the summer period of this year, says: 'Our fieldwork results are a key indication of the rapid changes now being seen in and around Greenland, which are evident not just on this glacier but also on many surrounding small glaciers. It's clear that this is now a very dynamic environment in terms of its response and mass wastage to ongoing climate change.

'The retreat of these small glaciers also makes the nearby Greenland Ice Sheet more vulnerable to further summer warming which is likely to occur. There could also be an effect on North Atlantic Ocean circulation and weather patterns through the melting of so much extra ice. An extended glacier observation programme in east Greenland for the next few years is clearly needed to improve understanding of the links between climate change and response of the glaciers in this important region.'