Special Correspondent

Peak ground acceleration on the dam is 0.21 g

A quake could cause extensive damage to the dam

THIRUVANANTHAPURAM: A study conducted by IIT-Rourkee has found that the peak ground acceleration (PGA) on the Mullaperiyar dam is 0.21 g, Water Resources Minister N.K. Premachandran said here on Wednesday.

[Peak ground acceleration is a measure of how hard the earth shakes in a given geographical area.]

Talking to reporters, Mr. Premachandran said the site-specific study commissioned by the State government had pointed out that a quake could cause extensive damage to the dam.

Earlier study

An earlier study conducted by a team headed by R.N. Iyengar in 2001 had pegged the PGA at 0.16 g. Prof. Iyengar’s studies were based on the findings of earthquakes that rocked Koyna and Uttar Kasi.

The Tamil Nadu government rejected the findings on the ground that it was not a site-specific study. A study conducted by the Central Water Commission put the PGA at 0.1g. But, further studies conducted by experts put the PGA at 0.12 g. As per Indian standards, the PGA of Mullaperiyar region is 0.18.

M.K. Parameswaran Nair, who represented Kerala in the committee, tried to drive home the point, but it was rejected. Mr. Nair then recorded his dissent.

It was in this context that the State government entrusted IIT-Rourkee with the site-specific study.

The latest study pointed out the need to construct a new dam, adopting international technology, to overcome such threats.

It has been clearly proved that an earthquake measuring three on the Richter Scale may occur near the dam and cause extensive damage.