To understand quakes triggered by reservoirs, the government plans to drill deep into the last wilderness of the north Western Ghats
Tehelka, 8 June, 2012
THE HUMAN mind is brilliant, and enterprising. First we build dams and drown vast stretches of wilderness under reservoirs. But such artificial loads of water cause frequent, at times deadly, tremors. So next, we want to understand the quake dynamics by digging a few kilometres into the earth, threatening the remaining forests in the vicinity.
Since the impoundment of the Shivajisagar reservoir in 1962, Maharashtra’s Koyna region has suffered thousands of earthquakes. Typical examples of Reservoir Triggered Seismicity (RTS), more than 225 quakes of 4-6.3 magnitude on the Richter scale have been recorded in a pocket of 600 (20x30) sq km in the past 50 years. What made the RTS more pronounced here was the creation of a second reservoir at Warna, about 20 km from Koyna, in 1993.
For scientists, this was a great opportunity to understand quakes. In March 2011, Minister for Earth Sciences Ashwani Kumar said, “Efforts are underway to build a new scientific initiative, especially to understand the seismic activity of Koyna region in detail by drilling deep boreholes… an MoU has been signed on 7 January 2011 with the German Research Centre for Geosciences on behalf of the International Continental Scientific Drilling Programme (ICDP) for an initial period of five years.”
The same month, 70 experts — 26 of them from abroad — attended a workshop at National Geophysical Research Institute (NGRI) on ‘Deep Scientific Drilling to Study Reservoir Triggered Earthquakes at Koyna’ to chalk out a project for studying the physical, geological and chemical processes and properties of this quake zone in real time. Funded by the Centre, the project involved drilling a 7-km deep borehole and the cost was pegged between Rs 200-Rs 400 crore.
A few proposed drilling sites are inside Chandoli National Park, which, along with Koyna Wildlife Sanctuary, became the Sahyadri Tiger Reserve in 2007. Drilling bores to the depth of 1,000-10,000 metres will require heavy machinery. Road construction and vehicular movement apart, this will necessitate supply of water and electricity to the core of the tiger reserve through pipelines and power pylons. Realistically, one would expect the habitat to be scarred by onsite constructions and dumping of drilling mud.
Since initial results are not expected before a decade, the damage on the only tiger reserve in the north Western Ghats will be sustained and irreversible. Aggressive chemicals are often used to clean materials brought up in drilling mud. If contaminated mud is dumped in open pits, it will pollute the fragile ecology. If dumping pits are dug up to bury the sludge, it will cause further destruction to this tiger habitat.
This April, when N Purnachandra Rao, project leader and NGRI’s senior principal scientist, sought permission from the state Forest Department for site reconnaissance, he referred to the forest as Chandoli National Park instead of Sahyadri Tiger Reserve. The ambiguity stuck in the permission granted by SWH Naqvi, Principal Chief Conservator of Forests (Wildlife), Maharashtra, to a 12-member team of scientists led by NGRI chief scientist Prakash Khare.
However, Naqvi forwarded the letter of permission to the National Tiger Conservation Authority (NTCA) and the latter, it is learnt, has referred the project to the National Board for Wildlife earlier this week. “My permission was purely for reconnaissance purpose and it did not allow any scientific experiment, digging or removal of stones. If they (NGRI) seek permission for drilling, we will refer it to NTCA and NBWL,” says Naqvi.
Meanwhile, the NGRI team conducted a survey from 29-31 May. Rao explains that his teams will continue to examine different sites for feasibility. “It will take another two years before we pinpoint the most suitable site and start drilling. We are trying to avoid the tiger reserve. But if we need to drill there, we will seek all the necessary permissions,” assures Rao.
The Sahyadri tigers may just run out of luck.
Tehelka, 8 June, 2012
THE HUMAN mind is brilliant, and enterprising. First we build dams and drown vast stretches of wilderness under reservoirs. But such artificial loads of water cause frequent, at times deadly, tremors. So next, we want to understand the quake dynamics by digging a few kilometres into the earth, threatening the remaining forests in the vicinity.
Since the impoundment of the Shivajisagar reservoir in 1962, Maharashtra’s Koyna region has suffered thousands of earthquakes. Typical examples of Reservoir Triggered Seismicity (RTS), more than 225 quakes of 4-6.3 magnitude on the Richter scale have been recorded in a pocket of 600 (20x30) sq km in the past 50 years. What made the RTS more pronounced here was the creation of a second reservoir at Warna, about 20 km from Koyna, in 1993.
For scientists, this was a great opportunity to understand quakes. In March 2011, Minister for Earth Sciences Ashwani Kumar said, “Efforts are underway to build a new scientific initiative, especially to understand the seismic activity of Koyna region in detail by drilling deep boreholes… an MoU has been signed on 7 January 2011 with the German Research Centre for Geosciences on behalf of the International Continental Scientific Drilling Programme (ICDP) for an initial period of five years.”
The same month, 70 experts — 26 of them from abroad — attended a workshop at National Geophysical Research Institute (NGRI) on ‘Deep Scientific Drilling to Study Reservoir Triggered Earthquakes at Koyna’ to chalk out a project for studying the physical, geological and chemical processes and properties of this quake zone in real time. Funded by the Centre, the project involved drilling a 7-km deep borehole and the cost was pegged between Rs 200-Rs 400 crore.
Since initial results are not expected before a decade, the damage on the only tiger reserve in the north Western Ghats will be sustained and irreversible. Aggressive chemicals are often used to clean materials brought up in drilling mud. If contaminated mud is dumped in open pits, it will pollute the fragile ecology. If dumping pits are dug up to bury the sludge, it will cause further destruction to this tiger habitat.
This April, when N Purnachandra Rao, project leader and NGRI’s senior principal scientist, sought permission from the state Forest Department for site reconnaissance, he referred to the forest as Chandoli National Park instead of Sahyadri Tiger Reserve. The ambiguity stuck in the permission granted by SWH Naqvi, Principal Chief Conservator of Forests (Wildlife), Maharashtra, to a 12-member team of scientists led by NGRI chief scientist Prakash Khare.
However, Naqvi forwarded the letter of permission to the National Tiger Conservation Authority (NTCA) and the latter, it is learnt, has referred the project to the National Board for Wildlife earlier this week. “My permission was purely for reconnaissance purpose and it did not allow any scientific experiment, digging or removal of stones. If they (NGRI) seek permission for drilling, we will refer it to NTCA and NBWL,” says Naqvi.
Meanwhile, the NGRI team conducted a survey from 29-31 May. Rao explains that his teams will continue to examine different sites for feasibility. “It will take another two years before we pinpoint the most suitable site and start drilling. We are trying to avoid the tiger reserve. But if we need to drill there, we will seek all the necessary permissions,” assures Rao.
The Sahyadri tigers may just run out of luck.
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