Seismic forensics could help develop a flood warning system in the future.
In the future, seismic forensics could aid scientists in developing an early warning system for rockslides and floods.
A huge rockslide in India’s Dhauli Ganga Valley triggered a devastating flood on February 7, 2021. More than 200 people were murdered, and two hydroelectric power facilities were damaged, as a result of the flood.
Researchers utilized data from a network of seismometers to piece together the minute-by-minute seismic signals of the rockslide and following flood in a new study published Thursday in the journal Science.
Although scientists have yet to identify what caused the disaster, they do know that 20 million cubic meters of ice and debris fell off the slopes of Ronti Peak, a mountain glacier, and into the Ronti Gad River shortly after 10:20 a.m. local time.
The first seismic signal of the rockslide was recorded at 10:21 a.m. and 14 seconds local time. The avalanche of rock and ice landed on the valley floor less than a minute later. A rumble the size of a magnitude 3.8 earthquake was produced by the hit.
According to seismic data, the rockslide was moving at speeds of over 60 miles per hour when it first hit the river valley’s bottom. It slowed to fewer than 25 miles per hour as it moved downstream.
The torrent of water displaced by the barreling mass of rock and ice reached a bridge in Joshimath just over half an hour after the original rockslide, when sensors showed a 52-foot increase in water levels.
Instruments at the Chinka gauge station further downstream recorded a 12-foot rise in water levels.
Researchers separated the disaster into three phases based on seismic data: the first rockslide and impact; the subsequent rush of mud, rocks, and water that surged like a wall down the river valley; and finally, the protracted flow of flood waters.
In a news release, research author Niels Hovius, acting scientific director of the GFZ German Research Center for Geosciences, said, “The data from seismic instruments are ideal as a basis for an early warning system that warns of the coming of such catastrophic debris flows.”
The efficiency of a seismic warning system is determined by a number of elements, including the original location of the rockslide and the pace with which the wall of material is moving.
Most crucially, a dense network of seismometers is required, with the number of seismometers increasing… Article Summary from Nokia News