A day after a powerful earthquake struck Tibet’s Shigatse region, with tremors felt across Bhutan, the National Centre for Hydrology and Meteorology reported a massive avalanche sweeping through the Bechung Glacier near Thanza village in Lunana Gewog. The earthquake’s impact was strongest in Bhutan’s Gasa district, which registered an intensity of magnitude four. No casualties have been reported in the area.
The earthquake, which struck near Shigatse in Tibet yesterday, had a magnitude of 7.1.
The earthquake’s effects were most pronounced in the western and northern regions of Bhutan, particularly in Lunana Gewog, an area home to high-risk glacial lakes.
Earthquakes can trigger avalanches, which are one of the major causes of Glacial Lake Outburst Floods.
However, according to the NCHM, the recent avalanche fell onto Bechung Glacier, avoiding critical glacial lakes such as Thorthormi and Raphtstreng.
“If an avalanche of such magnitude had fallen on Rahphstreng or Thorthormi lakes, especially as these two are located right at the base of the Table mountain, then since avalanches are triggering factors for GLOF, it could have generated huge wave in the lake. And those waves as they pass and hit the end moraine path, then they strike the moraine and are the triggering factor of dam failure,” said Phuntsho Tshering, the Principal Hydromet Officer with NCHM.
Currently, a minor sliding has occurred on the inner moraine walls of the Thorthormi-Raphstreng barrier which the team in Lunana will continue to monitor.
The centre has cautioned the staff at Lunana to be vigilant. The team will continue to make field visits to lake sites in the coming days. The centre will keep monitoring the situation.
Samten Dolkar
Edited by Kipchu
