Even as the state is yet to recover from the devastating September 18 tremor measuring 6.8 on the Richter scale, scientists say that more earthquakes in the seismic region are overdue.
"Any earthquake particularly in the hilly region which is always considered topographically vulnerable, will experience a morphological and topographical change but the extent of change after this quake cannot be assessed right now. It will take some time," said Paritosh Bhaumik, senior geologist of Geological Survey of India in Sikkim.
When asked whether the quake will affect the course of Teesta, Bhaumik said, "Though Teesta doesn't fall in the seismological weak lineament but another earthquake in the region will lead to the increase of glacial lakes and it will definitely affect the course of the river".
"There are glacial lakes like Changekhempu and Zimo at Gurudambar lake which feeds Teesta. In the event of an quake these might start melting and increase in the flow of water will lead to flash floods and it might even too some extent change the course of the river," Bahumik said.
"Moreover, there are many small glacials in Lachenchu region which might start melting and we cannot also ignore the possibility of the creation of new glacials but these are all subject to epicenter of the quakes and the intensity of it," Bhaumik said.
However, geophysicist of the Wadia Institute of Himalayan Geology in India Sushil Kumar said, "If the acceleration is high at the epicenter of the earthquake, nothing will be stable and the glacial lake will bust. Unfortunately, a number of these lakes are located near seismic faults".
Officials with Nepal's National Seismological Centre said that at least half a dozen minor tremors are recorded in the Himalayas every day. "The main reason why we have not witnessed the busting of glacial lakes is because the region has not been hit by big earthquakes in recent times," Dilram Tiwari of NSC said.
"And when the magnitude of the tremor is five or above we record many after shocks as well. We know that these activities are happening in the Himalayas but we cannot confirm whether they are happening in the nearby glacial lakes because there are hardly any seismic meters installed near the glacial lakes," he said.
