Causes of earthquakes in India
By Naresh Kochhar

PHYSIOGRAPHICALLY and tectonically, India can be divided into three broad ones: Peninsular India, Indo-Gangetic plains and the Extra-peninsular India (Himalayas).

The peninsular India comprises shield elements which are supposed to be geologically stable. But recent earthquakes of Jabalpur and Latur have shown that the shield areas are also prone to earthquakes. Himalayas as we know are seismically very active and there have been recent earthquakes e.g. Chamoli and Uttarkashi. Uttarkashi areas fall on main central thrust (MCT) whereas Shimla-Dehra Dun-Almora belt lies on the main boundary fault (MBF).

Gujarat, Kutch and Saurashtra and adjoining areas form a part of the western India shield. This region is known to be seismically active since historical times. There have been earthquakes in Rann of Kutch (1819), Surat (1856, 1864), Broach (1970); Koyana (1967), Latur (1993) and Jabalpur (1997).

The Gulf of Cambay lies on the triple junction as three major tectonic lineaments originate from here: Cambay rift and Panvel flexure running in north-south direction and Narmada-Son rift in EW direction. The Narmada-Son lineament is seismically very active and marks the boundary between shield and Indo-Gangetic plain (Fig. 1). What is a rift? Pulling apart of crust due to tensional stresses resulting in dropping down of elongated block. It is a weak zone vulnerable to tectonic movements.

The geological evolution of the region around Gujarat has been largely influenced by reactivation of primodial faults now occupied by these rifts. The region is characterised by high heat flow, gravity high and thinning of crust (16 to 20 km depth) as compared to the normal 35 km depth in the adjoining areas. Recently, Australian scientists have delineated a low seismic velocity zone beneath Cambay graben inicative of the presence of "fossil plume". Thus there is a crustal heterogenity in the areas besides the tectonic junction of three main rifts.

According to scientists of the National Geophysical Research Institute (NGRI), Hyderabad, the sea floor in the Indian Ocean is spreading and thereby pushing land inwards in northeasterly direction at the rate of 5 cm per year and at the same time Saurashtra region is rotating in an anticlockwise direction. The advancement of sea-floor against Indian plate amounts to nearly 125 to 150 cm in 25 to 30 years. It causes earthquakes not only at the edge of Indian plate and elsewhere in the Himalayas. The rifts are inherently unstable due to pushing and movement of the Indian plate towards north.

The system seems to activate itself in the weak zones every 25 to 30 years because of the shift.

The Bhuj earthquake is an example of intraplate (within plate) earthquake as opposed to the Himalayan earthquakes which are due to collision of plate boundaries. Intraplate stresses are due to the northward movement of Indian plate as a whole; and also due to heterogenity of the plate and the presence of weak zones such as fault, rifts etc. Bhuj and Latur earthquakes are examples of stable continental region earthquakes.

Disaster management: Unfortunately, there has been no government policy to handle natural disasters. There is an urgent need to have interaction with scientists from NGRI and Wadia Institute of Himalayan Geology, Dehra Dun, who can help the local administration in identifying vulnerable areas (Gujarat earthquakes appear to be cyclic) and also taking steps to construct quakeproof/resistant houses. The houses in such areas should have lintel beams, dome shaped roofs and thick iron netting in their construction. Strengthening of joints between the vertical columns and the horizontal beams around which a reinforced concrete and cement structure is built, is recommended.

Such houses can withstand quake even seven on the Richter scale.

The Richter scale was devised in 1935 by Charles Richter, a US seismologist. The scale is logarithmic-it means that each step up the scale represents a 10-fold increase in the amplitude of energy wave emitted by the quake. It starts with terrestrial tremors detectable only by instrument (Magnitude 1) through to detectable within 20 miles of the epicentre (Magnitude 4-5) and moderatively destructive (Magnitude 6) to major quake of Magnitude 7 and 8.

Magnitude of Bhuj earthquake has been compared to detonation of a 69 megaton hydrogen bomb.

2000: A brilliant year for science
By Savita Verma

THE year 2000, which began defying all doomsday stories and the much-hyped Y2K bug, marked several victories for scientists the world over.

Indian science in particular had a special year with an Amritsar-born scientists getting the World Food Prize and many developments taking place in the areas of space communication, missile technology, medicine and biotechnology.

The year began on a happy note with the Prime Minister announcing increase in the country’s research budget from 0.86 per cent of the GDP to 1 per cent and further to 2 per cent over the next five years. At the same time alarm bells started ringing with the birth of a baby girl "Aastha", who marked crossing of the one billion-mark of the country’s population.

However, the country moved a step ahead in checking the population-explosion by framing a National Population Commission to achieve the goal of population stabilisation by 2045 and fertility replacement level (two children per couple) by 2010. The commission will, especially, focus on states like Bihar, Madhya Pradesh, Rajasthan, Uttar Pradesh and Orissa, which house 44 per cent of the nation’s population and show poor socio-economic growth.

Indian science was adorned with yet another feather in its cap when Amritsar-born plant geneticist Dr Surinder K. Vasal shared this year’s World Food Prize with his colleague at the International Maize and Wheat Improvement Centre, Dr Evageliana Villegeas, for development of a protein-rich maize called "quality protein maize". He is the fifth Indian winner of the prize.

The new maize variety will help address the problem of malnutrition in developing countries as it contains twice as much useable protein and yields 10 per cent more grain than traditional varieties grown in the tropics.

IN the space scenario, India took a big leap forward by testing the first indigenous cryogenic engine and launching INSAT 3-B. Ignition of the cryogenic engine, which used liquid hydrogen and liquid oxygen as propellants, at the Liquid Propulsion Systems Centre (LPSC) of the Indian Space Research Organisation (ISRO) in Mahendragiri in Tamil Nadu, on February 16, marked another milestone in self-reliance.

ISRO started building a cryogenic engine after Russia under international pressure in 1992-1993 decided against selling cryogenic technology to India, breaking a deal finalised in 1991.

In another development INSAT 3-B and its co-passenger US radio broadcast satellite Asia Star rode into space abroad the new European launcher Araiane 5 from Kourou in France Guiana. The satellite would enhance India’s capability in education, literacy and development communication. — (PTI)

Innovative water lifting device
By G.S. Dhillon

THE device described is the "Water-current Turbine Pump" which is capable of lifting water from fast flowing water bodies like canals and hilly torrents and does not need either electricity or diesel power for working. The device is capable of extracting kinetic energy from fast flowing streams and converting it to "shaft power", which is used for working a centrifugal pump. The device is useful as it can work in isolated locations and meet water requirements for irrigation or domestic purposes.

The WCT(Water-Current Turbine) pump can work where the flow velocity ranges between the limits of 0.6 m/sec. to 1.5 m/sec.. The units developed require a minimum water depth of 2.5m.

In figure1, the device developed by a British firm (Thorpton Energy Services of Northumberland) is shown, which can work in flows up to 2 m/ sec., as above that flow velocity the "drag force" becomes excessively high needing special moorings and pontoon arrangement for safe operation.

The device works as an underwater Wind-mill floating on the water surface, with rotor fully submerged. The whole set up is tethered in free stream with mooring done to only one bank so as not to obstruct the movement over the water surface.

After considerable research, the most suitable configuration of the rotor was determined to be with inclined axis and the blades having constant hydrofoil section and fixed pitch. These type of sets have yielded rotor efficiency of the order of 30 per cent . The units are available which can lift water through 25m for irrigation or other purposes. The maximum volume of water lifted is 47 cubic metres per hour. Water delivery at a site would depend upon not only the extent of lift involved but also on the flow velocity. The table below lists some of the data available in this regard.

The Garman Water Current Turbine Pump set up shown in the figure, is thus an irrigation pump which uses the energy of the flowing water and its capital cost is claimed to be smaller than equivalent solar or wind powered system. The operating cost of this device is insignificant compared with the operation cost of disel engines. The useful design life of the setup is put at 12 years.

The Garman WCT pumps have been field tested and refined, for over 15 years in Egypt, Sudan, Somlia and Peru. The set up is found to be easy to operate and maintain. It does not require large scale civil engineering work and can be moved from one location to another easily. It is possible to undertake manufacture of the device locally using local material and local talent. The device can be operated for 24 hours/ day without any full-time attention.

If at the site the flow velocity change occurs of more than 40 per cent from the rated design value, it is necessary to change the rotor of different diameter. But in the case of the canals the flow obtained is fairly steady, so such a change may not be necessary. However it may be stated that if a change is needed, it would involve changing the blades and altering the transmission ratio to the second stage belt. Both the intermediate shaft pulley and the pump pulley are stepped so that belt can be moved across without the need to re-tension. An important part of the O &M is to keep the unit free of the floating or submerged trash.

In the head reaches of the canals no supplies are given for irrigation as the section of the canal is always in "deep cutting" requiring arrangement for lifting of water. At many locations electric supply is not available. The farmers of such locations grumble that water is being taken to lower reach farmers without meeting their requirements. The device described can overcome the difficulties and make available water to these farmers.

In the hills one may have a fast flowing stream and on its bank it is required to set up a tented accommodation for which it is required to lift water for meeting the drinking water and other needs. This device can start working without much loos of time and can be shifted to another location when its requirement at the site ceases this innovative device, the Water -current Turbine pump, is an eco-friendly device and can be used for supplying irrigation to lands located at higher level than its banks. It can be used in emergency situation to meet water requirements for relief camps or temporary construction camps.

NEW PRODUCTS & DISCOVERIES

THE most advanced computerised system for gait analysis and the study of human bio-mechanics, Vicon, processes information from up to seven cameras, to present a moving three-dimensional image that can be viewed on the monitor screen from any angle.

Developed in Britain, it is a valuable new research tool for orthopaedic specialists and makes possible rapid assessment of disabilities by staff at medical clinics. The system will also facilitate research on designs of replacement joints and analysis of actions in sports and robotics.

High definition images are recorded at 50 frames per second. The patient is illuminated by high intensity infra-red strobes with a flash duration of two milliseconds. The unseen light is reflected by special passive markers which are stuck to key flexion points of the body as the patient walks or runs in the cameras’ field of view.

From the two-dimensional trajectories of reflected light, captured by two or more cameras, the computer can mathematically create a model of three-dimensional motion measuring the forces, movements and positions of muscles and limbs. Further e-data can be obtained through force plates built into the laboratory floor and electromyograph signals transmitted from tiny pre-amplifiers taped over muscles.

Vicon’s computer can quickly calibrate the relative positions of the cameras which can be moved to show different views and attend to various complaints, including an unobscured bird’s eyeview of pelvic rotations, impossible to record with old filming methods of studying human motion. The system can support multiple users, depending on the power of the main computer, or can be made portable.

Partial skeleton of the world’s smallest whale has been discovered in India in the 45 million year-old rocks of Kutch, scientists have reported. They have named this new fossil whale "Kutchicetus minimus."

Sunil Bajpai in the Earth Sciences Department of Rorkee University and co-worker JGM Thewissen of Northeastern University College of Medicine in Ohio in United States have made the unique discovery.

Reporting their finding in Current Science, they claim the fossil represented a new genus in the family Remingtdonocedidae.

This new species, which was found in a chocolate-coloured muddy limestone near the village of Godhated in Western Kachchh, was probably the smallest known Eocene whale in the world, Bajpai said.

The skeletons they discovered included teeth, skull fragments, limb bones and a relatively complete vertebral column.

"The discovery is of considerable importance because it provides independent fossil evidence to show that whales may have gone through an intermediate evolutionary stage where their swimming mode resembled that of modern otters," Bajpai said. 
— (PTI)

Researchers have developed a new method, using the rare gas helium, that markedly simplifies and economises the search for leaky pipes in heating systems and pipelines for drinking water.

Leaking pipes lead to the wastage of both energy and costly purified water in the West. Besides the attendant moisture and exposure to air deteriorates the insulation and pipe material.

The new process, developed by researchers at the Fraunhofer Institute for Environmental, Safety and Energy Technology UMS CHT, Oberhausen, can detect even small holes in pipes without disrupting their operation.

The key to the process developed with the financial support of the German Federal Ministry of Education is helium. It is dissolved in flowing heating water in small amounts, so that it is distributed evenly in the pipe network. Where leaks appear, the gas escapes with the water and penetrates through the earth to the surface. Using a portable device, technicians can measure the concentration of helium in the air near the ground with parked cars interfering little with readings.

The process has advantages as helium is not poisonous to human beings or the environment. It is readily detectable in small concentrations and as it is not flammable, can be utilised without safety precautions. Because of its small atoms, helium passes quickly through the surroundings of the damaged pipe, making it easily detectable.

Scientists have succeeded in developing very small sized particles which can escape body’s defence mechanism and be loaded with drugs, opening up the possibilities for their use in targeting drugs at specific sites in the body.

The development holds enormous significance for treatment of diseases like cancer. Problem with cancer treatment is that drugs used are highly toxic which also kill normal cells, causing several side effects. — (PTI)

Science quiz
J.P. Garg tests your IQ

1. A Laboratory for Conservation of Endangered Species is being set up at Hyderabad at a cost of Rs 5 crore to clone an Indian animal that became extinct about 50 years ago. Which is this animal? Who is heading the team of scientists for this first attempt at cloning in India?

2. Bermuda Triangle in the North Atlantic Ocean is well known for causing boats and ships to sink. Now it has been found that an ocean spot in the North Sea, called Witch Ground, behaves similarly. The cause of this behaviour is the emission of methane gas in spurts from under the seabed. Can you think how this sinking action takes place?

3. ELISA is a diagnostic technique used to detect antigens and antibodies of HIV virus and for diagnosis of hepatitis, infections due to fungi, etc. What is the full name of this test?

4. This plant is easy to grow in the laboratory, has a short life cycle and has a small genome. Thus it is the first plant the genome of which has been sequenced completely. Which is this plant?

5. When a solid takes up a liquid or gas (or a liquid takes up a gas) and the liquid or gas permeates the whole bulk of the solid, the process is called absorption. What is the process called when the substance taken up remains only on the surface of the solid?

6. This cycle of operations for an ideal reversible heat engine comprises four operations done on the working substance and shows that an engine can never convert all the heat energy supplied to it into mechanical energy. What is this cycle called?

7. Name the instrument used mainly by mineral collectors to help identify the crystal forms by measuring the angles of crystal faces.

8. What is a chemical bond called in which two atoms share a pair of electrons, one from each atom? What are the three types of this bond?

9. This invisible electromagnetic radiation has wavelengths between those of visible light and radiowaves. It can penetrate fog or haze which would scatter ordinary visible light, making it particularly useful in astronomy. Which radiation are we talking about? Who discovered this radiation?

10. The world’s first robot that eats and digests to generate its own power is 12 metre long and rolls on 12 wheels. Can you name this robot that is powered by a microbial fuel cell filled with E. coli bacteria?

Answers

1. Indian cheetah; Dr Lalji Singh 
2. Methane gas lowers the density of water causing anything like a boat to sink suddenly 
3. Enzyme Linked Immuno Sorbent Assay 
4. Arabidopsis thaliana 
5. Adsorption 
6. Carnot cycle 
7. Goniometer 
8. Covalent bond; single, double and triple bonds 
9. Infrared radiation; English astronomer Sir William Herschel in 1800 
10. Gastronome.