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| SCIENCE TRIBUNE | Thursday, September 14, 2000, Chandigarh, India |
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Science
Quiz |
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BEING one of the world’s youngest and the highest mountain ranges, full of geological complexities, the Himalayas afford a fascinating ground for the geological to unravel its mysteries. The Himalayas owe their origin to a great sea known as the Tethys. It was on the bottom of this ancient mediterranean sea — Tethys (the present Mediterranean being a remnant pool of that great sea which prevailed right up to China on the east) that the body of the Himalayas was built. Thousands of feet of sediments were deposited on this sea floor separating the continent of the north Angaraland from the southern Gondwanaland. As these deposits grew thicker and heavier the bottom kept sinking. Ultimately a limit was reached when no further sinking was possible and this great overloaded trough underwent a reverse set of phenomena and was uplifted into a mountain system. The general configuration of the Himalayan chain, with its north-west, south-east arcuste trend, the almost abrupt steep border towards the great Indo-Gangetic plains of India, with the much more gentle slope towards the Tibetan side, led many geologists in the past to believe that the Himalayan chain emerged, as a result of the push of the Angarland to the south and the resistance offered by the peninsular foreland. However, in recent years, based on the evidences gathered by the marine scientists in the bottom of the Indian ocean, geologists support that the Himalayas rose as a result of the advancement of the Indian plate towards the north. The push offered by the moving Indian plateau to the north not only caused a crustal shortening of several hundred kilometres but also resulted ultimately in the uplift of the Himalayan mountain. Although, the southern limit of Himalayan basin is well-defined by the Himalayan foothill from Waziristan through Hazara and Punjab to Assam, the northern border of the ancient Himalayan sea cannot be known with accuracy. It is believed that the Himalayas have extended across the Brahmaputra through Yunan to China. Thus, the Himalayas do not end at the Indus or Brahmaputra but extend either westwards or southwards in both the directions. The Himalaya organic system, as it upheaved from the sea, unlike its contemporaries, the Alps and the Andes, gave rise to the largest, highest as well as youngest mountain of the world. Longitudinally, the Himalayas are dividend into the (i) Outer (ii) Inner (iii) Great Himalayas and (iv) the Trans-Himalayas. The rocks at the foothills i.e. the outer Himalayas were deposited as a result of the rising Himalayas to the north. These outer Himalayas ranges known as the Shivalik range, were formed as a result of the uplift of the mountain ranges to the north, when the latter were subjected to severe denudation, the eroded material got deposited at the site of the rising mountains. It was during the Tertiary period that this area was inhabited by varieties of wild life, particularly mammalians and with the advent of the Great Ice Age many of the mammalian fauna perished and got buried in the sediments of the Shivalik range. These faunas are now found in plenty in the form of fossils, a few of which are stored in a number of museums, including those in Chandigarh, the Saketi Fossil Park (near Nahan) in Himachal Pradesh and in the Calcuttta Museum. The Inner Lesser Himalayas display a variety of sedimentary and metamorphosed rocks, with a complex geological and tectonic history. The older group of rocks are commonly found at the top of the younger sedimentary rocks as a result of horizontal movements and are known as “Nappe”. The Great Himalayas occupy the zone of maximum elevation and are made up of highly metamorphosed rocks intruded by large batholitic masses of granite. Acting as a water divide, they receive the maximum precipitation of snow, which covers large areas in the form of ice fields and also feeds a large number of glaciers from which many of the perennial rivers emerge and flow towards the northern plains of India. To the north of the Great Himalayan range, a complete record of marine fauna, which flourished during different geological periods in the Tethys, are found in the form of fossil remains. These fossils are found in plenty throughout the northern part of the Great Himalayas, including Kashmir, Lahaul and Spiti, Zanskar and the north-eastern part of UP, Nepal and Sikkim and Bhutan Himalayas. One of the most interesting phenomena that took place in the Tran-Himalayan region including Tibet, i.e. at the foot of the Ladakh range, on the west and the Kailash range on the east, is the formation of a great crustal depression which resulted in the development of line of dislocation at the end of a Creataceous period. This zone is presumed to have got reactivated with the northward push of the Indian plate. A great segment of the crust along the northern fringe, including the overlying younger sediments of the Tethys, got down-buckled along this line. Simultaneously upwelling of molten lava from the Magma chamber took place, which pushed sedimentary rocks upwards. Vast blocks of these rocks along with the lava, flowed southwards, juxtaposing the main rocks of the Himalayan basin. Geologists have calculated that these sedimentary rocks translated southwards from the foot of the Ladakh-Kailash range, have travelled to a distance of about 100 km to the south. These mountains are now known as the “Exotic Thrust Masses” and occupy a unique position in the annals of the Himalayas. Nowhere else in the world are there such large nappe/exotic masses transported or uprooted and displaced a few hundred kilometres from their root zone, except Tibet and the contiguous areas of the Himalaya. Vestiges of such a block was found by me in 1973 in the Paddar area of Kashmir, when I had gone there in connection with the Sapphire investigation. Paddar, I found, to be the only example of the exotic thrust mass to the south of the Great Himalayan range. The Himalayas not only form the zone of highest elevation, but also possess the most beautiful rocks, the largest and most beautiful valleys such as the Kashmir valley, the highest lakes and the longest valley type of glaciers within their fields. The Indus, Brahmaputra, Sutlej are typical examples of antecedent river drainage system; i.e. these rivers existed prior to the uplift of the mountain range. The geothermal springs occurring in the coldest environment of the Puga Valley are located at an altitude of 4000 m, where the GSI has done drilling. It is a pleasure to see the hot water gushing out in the form of a geyser. A number of geothermal springs also occur around the Central Himalayan region of Kumaon and Garhwal. One is surprised to see how kind nature has been in providing these hot springs in the cold environment of the Himalayas. Potentialities of natural resources such as limestone, dolomite, gypsum, soap-stone, magnesite, sapphire, geothermal fluids, natural gas etc. are known and are being explored more and more every year by the geologists in the Himalayan region. The writer is a former Director of Mines, Geological Survey of India. |
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Revolutionary plane concept
Boeing Aircraft Company, one of the leading plane manufacturers and designers, have developed a new concept to replace the ageing E-2C aircraft, dubbed an EX. The concept employs a joined wing technology to provide full spherical coverage for the aircraft’s sensor systems. The joined wing airframe has completed its first set of wind tunnel tests, and the wing mounted radar antennas have been fabricated and successfully tested in a one-fifth scale configuration by the Boeing Defence and Space Group Military Airplanes Division in Seattle, USA. The EX is envisioned as a replacement for the US Navy’s ageing E-2C carrier-based surveillance aircraft. The concept employs a joined-wing technology to provide full spherical coverage for the aircraft’s sensor systems. The diamond-shaped airframe has completed its first set of tests.
Atoms of antimatter
European scientists announced plans to build atoms of antimatter and then “cage” them for use in experiments, reports Associated Press. The researchers at the European Laboratory for Particle Physics, or CERN, said they plan to make atoms of antihydrogen. It would be the first time that antiatoms have been slowed down enough to be caught and studied. Physicists believe that antimatter is the mirror image of conventional matter in the universe. For every subatomic particle in the universe, there appears to be another identical in appearance and structure, but with its electric or magnetic properties reversed. Scientists have been puzzling for years over the disappearance of antimatter. The Big Bang should have created the same amount of matter and antimatter, and in principle the two should have wiped each other out. But somehow there was enough left over to create the universe, and antimatter only exists now in cosmic rays and particle accelerators. Using a small decelerator, the CERN scientists plan to test the antihydrogen atoms to see if they behave in the same way as ordinary hydrogen. If antimatter differs from matter, even by one part in a hundred billion, that could explain why the world is made up of matter and why antimatter has disappeared. The scientists hope to have the first ahtihydrogen atoms by the end of this year, and need to construct a new type of apparatus in order to trap them. Their aim is to give a first analysis by the end of 2002.
Handsfree phones
pose less risk
Mobile phone users can limit exposure to potentially dangerous radiation with handsfree attachments, Associated Press reports quoting a UK government study. The Department of Trade and Industry study found “substantial reductions” in radiation exposure when testers used a handsfree kit compared to holding a mobile phone directly to their ear. But U.K. consumers’ association questioned the report’s conclusions and methodology. A study by the association earlier this year found handsfree kits may act as aerials, channeling three times as much radiation into users’ heads. As yet, there has been no concrete medical evidence suggesting that radiation from mobile phones might cause cancer or other health problems. But at the same time, there is no definitive proof that cell phone radiation is harmless. The government study, conducted by independent consultant SARtest Ltd., found radiation readings dropped “significantly” when consumers used a handsfree kit. Tests were conducted on five types of phones with an internal external antenna.
New standard for heart
attack treatment
A clot-busting drug that is standard treatment for heart attacks is less effective than a new technique in which surgeons put a small mesh tube in an artery and give the patient “super aspirin,” a study indicates, reports Associated Press. The new method, tested at a Munich hospital, worked better because it saved move of the heart, doctors said, but it may not be practical in other countries because few hospitals are equipped to insert the tube quickly. In the study, published in the New England Journal of Medicine, doctors at the German Heart Center found that after six months, 8.5 per cent of the patients given the two-part treatment had died or had a stroke or another heart attack compared to 23.2 per cent of those who got the clot-buster ATP, they wrote. The new treatment limited damage to an average of 14.3 per cent of the left ventricle, the muscular champer that pumps blood out to the body, compared with 19.4 per cent damage in ATP-treated hearts. In the process, patients were given the “superaspirin,” called abciximab, with the stent inserted as soon as possible. Like aspirin, abciximab keeps platelets and proteins from clumping, but it is much stronger. |
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Science quiz 1. “Eureka! Eureka!”, shouted Archimedes. This fact is well-known. Do you know who made the following statement and when? “It was quite the most incredible event that has happened to me in my life. It was almost as incredible as you fired a 15 inch shell at a piece of tissue paper and it came back and hit you.” 2. Name the satellite sent by NASA in 1998 which recently observed solar flares as high as hundred thousand kilometres erupting from the surface of the sun. What can be the possible cause of such high and intense solar flares? 3. We now have in India two-wheelers with more efficient engines based on “D-fi Logic” technology. What is the complete name of this technology? 4. Eggs are a rich source of proteins, iron and vitamin B and can be had at any time. However, there is one disadvantage, especially for the elderly people. What is this disadvantage? 5. Both petrol and plant oils and fats have the same basic chemical structure. Both are made up of chains of carbon atoms, with each carbon atom surrounded by four hydrogen atoms. However, petrol consists of chains which are eight carbon atoms long, making it suitable as a fuel. What is the length of chains in plant oils due to which these oils do not act as a fuel? 6. Which product is formed by the action of nitric acid on mercury metal in the presence or alcohol? What is the main use of this product? 7. We hear a lot about ROBOTS. Can you tell the language from which this word has been derived? 8. What condition should be satisfied so that an ideal (Carnot) heat engine has 100% efficiency? 9. What is the transport tissue of a plant called, which conducts water and minerals from the roots to the rest of the plant and provides support? 10. This national park in Kullu district, which has about 45 species of medical herbs, is in the thick of a controversy because the government has banned the entry of locals to collect herbs from and graze their cattle in the park. Which is this park?
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