Thiruvananthapuram, Dec 21: If, and it is an admittedly big 'if', an earthquake, measuring 6 on the Richter scale, rocks Idukki district and the 116-year-old gravity dam in Mullaiperiyar bursts, with water level at 136 feet, the resultant flood would submerge 50 sq kms of land downstream, reports the Times of India.
The thundering water would flow at a height of 36 feet, submerging buildings, uprooting trees and leaving a trail of destruction. 
People living downstream would get 15-20 minutes to run for their lives, said John Mathai, a senior scientist with Centre for Earth Sciences (CESS) in Thiruvananthapuram.
The scenario is scary but quite probable, he claimed.
"Between 26 July and November 26, 2011, 26 low intensity tremors were recorded in the region. A major earthquake cannot be ruled out," Mathai told TOI.
Scientists at CESS have been conducting studies in the Idukki region since 2001 and have identified an active faultline in Idukki. CESS recently mapped the region to find out which areas would be inundated if there was a massive earthquake and Mullaperiyar dam burst. 
They also identified the high and the low points through which water would flow if the dam broke.
The study was done as part of the state's disaster management program following concerns expressed by residents that their lives and livelihood were at stake.
Disaster management experts in Kerala will use the CESS map to identify higher ground where people can be safely evacuated in case of a flash flood.
