Context:
India is on a mission to drill a 6-km deep hole in Koyna, Maharashtra
Scientific Drilling at Koyna:
- India’s sole scientific deep-drilling programme.
- Scientific Deep Drilling (SDD) programme – Enterprise of strategically digging boreholes to observe and analyse deeper parts of the Earth’s crust.
- Executed by – Borehole Geophysics Research Laboratory (BGRL) in Karad, Maharashtra, is a specialised institute under the Ministry of Earth Sciences
- Objective – To drill the Earth’s crust to a depth of 7 km and conduct scientific observations.
- Reason for choosing Koyna – Recurrent earthquakes since the impounding of Koyna Dam (Shivaji Sagar Lake) in 1962.
- Technique used at Koyna – Hybrid of mud rotary drilling and percussion drilling (air hammering)
- Rotary drilling – Uses a steel rod to cut rocks which generates heat.
- Cooling liquid or drilling mud cools the tools and removes debris from the borehole.
- Air hammering – Pushes highly compressed air through the drilling rod to deepen the borehole and flush the cuttings out.
- Rotary drilling – Uses a steel rod to cut rocks which generates heat.
Source: The Hindu
Previous Year Question
Consider the following:
1. Electromagnetic radiation
2. Geothermal energy
3. Gravitational force
4. Plate movements
5. Rotation of the earth
6. Revolution of the earth
Which of the above are responsible for bringing dynamic changes on the surface of the earth?
[UPSC Civil Service Exam – 2013 Prelims]
(a) 1, 2, 3 and 4 only
(b) 1, 3, 5 and 6 only
(c) 2, 4, 5 and 6 only
(d) 1, 2, 3, 4, 5 and 6
Answer: (d)
