Shimla: Global warming is diminishing the Chhota Shigri glacier in the Pir Panjal ranges of Himachal Pradesh at 0.67 metres a year, report French and Indian researchers.
The study, jointly supported by the Department of Science and Technology, India’s space agency ISRO and the Indo-French Centre for Promotion of Advanced Research, concluded that the glacier mass was thinning more rapidly this century.
The researchers, including those from New Delhi’s Jawaharlal Nehru University (JNU) and glaciologists from France, said that the glacier was losing ice due to rising atmospheric temperatures.
The decrease is measured in terms of the ice flux, or the volume of ice passing a point per year.
“Our data suggests that the ice fluxes have diminished by 24 percent to 37 percent below 4,750 metres above sea level between 2003 and 2010,” said Pottakkal George Jose from the JNU School of Environmental Studies and a member of the research team.
Team leader A. L. Ramanathan said the thinning of Chhota Sigri glacier, located about 100 km from the hill resort of Manali, had picked up speed this century.
“This rate of less than a metre of mass loss per annum is an increase that occurred in this century, over the lower level of ice mass reduction in the preceding decade,” said Ramanathan .
The conclusion is supported in a study published in the 2012 edition of the Journal of Glaciology. “The glacier must have experienced a period of near-zero or slightly positive mass balance in the 1990s, before shifting to a strong imbalance in the 21st century,” the study stated.
Another study of Chhota Sigri during 1987-89 by the Wadia Institute of Himalayan Geology (Dehradun) reported that glacial thinning has been more rapid in this century.
A comprehensive study of Himalayan glaciers done with satellite imagery by ISRO reported that over 75 percent of them are on the retreat. It added that 17 percent of the glaciers were stable, while the remaining eight percent had actually grown in mass.
The ISRO study, released last year, came at the back of a raging controversy over a 2007 report of the UN Intergovernmental Panel on Climate Change (IPCC), which claimed that Himalayan glaciers were likely to disappear by 2035 owing to global warming.
The IPCC later acknowledged their report to be erroneous.
Located in the Chandrabhaga river basin in Lahaul and Spiti district, the Chhota Shigri glacier is about nine kilometres long.