Regarding Glacial Outburst in Sikkim

Press Release from Secretary, Department of Science and Technology & Climate Change

This has reference to the News Article that had appeared in some of the local dailies on 11th February 2013 with regard to Scientists warning of a huge Glacial Outburst in Sikkim. The news item has the potential to create widespread panic among the public regarding the glacial outburst. Therefore, the Department of Science and Technology and Climate Change, Government of Sikkim has found it necessary to clarify the factual position about the Glacial Lake.

The News Article was based upon a Research Paper published in the Current Science Magazine on 10th February 2013 by three Researchers of the National Remote Sensing Centre, Hyderabad. Their study was based upon the remote sensing satellite images of the South Lhonak Glacier in North Sikkim and the Glacial Lake formed below the glacier. The Researchers have predicted on the basis of the satellite imaginary that there is a likelihood of a Glacial Outburst Flood (GLOF) due to the increasing size of the Glacial Lake. Though they have stated in their report that there is a high probability of GLOF at the South Lhonak Glacier Lake, they have qualified their statement by saying that such natural hazard are unpredictable and that more detailed field surveys are required to establish the risk of a GLOF.

The State Remote Sensing Centre at Gangtok under the Department of Science and Technology and Climate Change, Government of Sikkim, has been studying the South Lhonak Lake for the past two years. Based upon satellite images dating as back as year 1976 till 2012, it has been conformed that the lake has been steadily growing in size and volume. In order to have a first hand knowledge of the Lake, an expedition by the project Scientist of the Department was undertaken in April 2012. The team visited the South Lhonak Lake, inspected the moraine dam formed around it and took photographs of the lake and dam for further study. The inspecting team was of the opinion that considering the size, shape and slope of the moraine dam and the existence of an outlet for the lake, there is no likelihood of a GLOF in the immediate future. This view is strengthened by the fact that despite a high magnitude earthquake that had its epicenter not far away from the lake, there was no GLOF from the South Lhonake Lake. In other words, the moraine dam of South Lhonak Lake is strong enough to withstand the pressure of a high magnitude earthquake.

The Centre for Development of Advanced Computing (CDAC), Pune, has also been monitoring the South Lhonak Lake for some time now. With the assistance of the Department of Science and Technology, Government of Sikkim, CDAC has plans to install Sensors (Early Warning System) around the lake for regularly monitoring the rise in the water level and to send alarms on the occurrence of GLOF. However, this is being done on an experimental basis, the result of which would help in further development of the Sensors.

Since the project Scientists of the Department have visited the lake and have studied the maraine dam, they are of the view that there is no likelihood of GLOF in the immediate future. Nevertheless, the department as a measure of abundant precaution, has requested the Ministry of Science and Technology, Government of India, to depute a team of experts on the subject to visit the South Lhonak lake, to confirm the likelihood of GLOF or otherwise, to suggest preventive and mitigation measures and to take necessary action as deemed fit. Similar requests are being made to the National Remote Sensing Centre, Hyderabad, from where the research paper on GLOF at South Lhonak Lake had originated. In addition, the Central Water Commission has been asked to continuously monitor the lake with high resolution Remote Sensing imagery.

To put it concisely, the Department of Science and Technology and Climate Change, Government of Sikkim, is abreast of the increasing size of the South Lhonak Lake, does not find any reason for an immediate alarm, and has been taking the appropriate action as required, as described above.