Sumatra quake ?cracks? the puzzle
EVEN AS the freak weather pattern ? clouding, high-velocity winds, thunderstorm and rains ? continued to baffle Bhopal and parts of the State on Thursday, Geophysicist and MAPCOST director-general Dr J G Negi advanced an theory to crack the puzzle.india Updated: May 26, 2006 13:07 IST
EVEN AS the freak weather pattern — clouding, high-velocity winds, thunderstorm and rains – continued to baffle Bhopal and parts of the State on Thursday, Geophysicist and MAPCOST director-general Dr J G Negi advanced an theory to crack the puzzle.
The unusual weather pattern being experienced in most parts of the subcontinent is the fallout of the unspent energy that was released as a result of the Great Sumatra Earthquake of December 26, 2004, Dr Negi said.
However, Meteorological Centre Director Dr D P Dubey said the weather was a pre-monsoon phenomenon with greater intensity. He said clouding over the subcontinent was a result of an upper-air cyclonic circulation (UAC), developed over the Orissa coast, was pulling in massive moisture causing rainfall in Orissa, Andhra Pradesh, south Chhattisgarh, parts of Madhya Pradesh and West Bengal.
Monsoon is expected to hit Kerala on May 28, ahead of its normal arrival. If the UAC over Orissa coast intensifies, monsoon may move fast into the subcontinent, Dubey said.
Dr Negi said a huge amount of frictional (heat) energy released during earthquake, measuring 9.3 on the Richter scale, remained unspent and was still affecting weather conditions. Now, having got a catalytic in the form of supporting winds and a recent earthquake in Indonesia of 6.8 magnitude, this unspent energy has churned out a huge cloud mass through evaporation.
This cloud mass is rolling in towards the subcontinent spanning almost the entire country except north-west states – mainly Rajasthan and Gujarat. A satellite imagery of May 25 shows the entire country including Madhya Pradesh under the huge cloud cover, he said.
The geophysicist said 45,000 megatonne frictional energy was released during the Sumatra earthquake and stored in a major rupture zone — 1,200 km long and 10-20 feet deep — on the ocean floor.
Coupling of several factors - mainly the release of pent-up energy (thatat’s causing clouding through evaporation), supporting wind direction (northerly over Indian Ocean and south-easterly over Indonesia) and recent Indonesia earthquake — has caused the heavy masses of cloud to move speedily towards the subcontinent.
Dr Negi said since the cloud masses were traveling long distances over sea, it is carrying massive energy that is causing severe thunderstorms.
Dr Dubey, however, said high-velocity winds and thunderstorms were being experienced because cloud masses have developed at a height – up to 15-16 kms- and such conditions lead to high speed winds and thunderstorm activities. He also said although the clouding was over a huge area, the rainfall activity was mainly concentrated over Orissa, Andhra Pradesh and South Chhattisgarh, some parts of Madhya Pradesh and West Bengal.
First Published: May 26, 2006 13:07 IST