Mountains roots

THE ROOTS OF THE MOUNTAINS!

The Bible states about the roots of the mountains ?

“People assault the flinty rock with their hands and lay bare the roots of the mountains.-– (Job 28:9 )

Is there any evidence that mountains have such deep roots? The most important point is that mountains have buoyant roots that extend downward into the mantle beneath a mountain range, and that the roots are, in general, about 5.6 times deeper than the height of the range. “Which by his strength setteth fast the mountains; being girded with power: — ( Psalms 65:6 ) It all began in India, when the British Raj was keen to reinforce its dominion by surveying the Empress’s possessions with the most modern techniques then available. The Great Trigonometrical Survey, as it was called, was meant to take 6 years and took about 60. During this time mapmakers crisscrossed India using two methods to determine their position, one providing a check on the other. The first method fixed positions on the ground like a sailor at sea, using the stars, the horizon and a sextant. The other was the process known as triangulation, whereby each point on the ground is fixed relative to another by measuring the intervening distance, and taking the compass bearing from each triangulation point to two others. The rest is trigonometry. When, during the mapping of the Gangetic Plain south of the Himalayas in the 1850s, these two methods were found to give widely differing results, the mapmakers found themselves in a spot of bother. It all came to a head over the difference in latitude between the towns of Kalianpur and Kaliana. These were supposed to be 370 miles apart. But their latitude measurements, determined using the two methods, differed by 550 feet. This did not much please India’s Surveyor General, Colonel (later Sir) George Everest. Astronomical measurement depended on the use of a plumb bob to level the instrument before readings were taken, and Everest had the idea that the extra gravitational attraction of the Himalayas might have been pulling the plumb away from true vertical. The Archdeacon of Calcutta, John Pratt, who happened to be a Cambridge-educated mathematician, was recruited to examine the conundrum; but his first results singularly failed to make things clearer. When Pratt compensated the astronomical readings for the expected extra gravitational attraction exerted by the mass of mountains that he could see, the observed discrepancy turned out to be much smaller than it should have been. The mountains were exerting less of a pull on the plumb bob than they should have done. It was as though they were hollow. When Pratt continued correcting readings taken in places near to the coast, the reverse was true. The ocean, despite its thick covering of less-dense water, seemed to be pulling the plumb bob much more than it should have done. Pratt and the mapmakers were on the verge of one of the most fruitful discoveries in all geology. The Archdeacon wrote a paper for the Royal Society. One of the things that makes science scientific is the fact that reputable journals will not publish anything before receiving the comments of one or more expert referees to whom they send every paper that comes their way. It is a process called peer review, and despite its occasional shortcomings, it remains a cornerstone of reliable science. Yes, there is abundant evidence from measurements of gravity over and near mountain ranges. Let’s first digress briefly to the equation that specifies the force of gravitational attraction between two masses that are separated by a distance r. F= G * m1 * m2 / (r * r) Here, G is a constant (the universal gravitational constant), and m1 and m2 are the masses of objects 1 and 2. The equation thus indicates that as the distance between two objectsincreases, the gravitational attraction between them decreases as the square of the distance. If the earth were perfectly spherical (i.e. no topography) and lacked any variation in density, then a mass that is hanging from a string (a plumb bob) would always point directly toward the earth’s center. In the 18th century, French scientists on an expedition to South America to measure the distance of a degree of latitude noted that the great mass of the Andes mountain belt represented additional mass that would exert its own gravitational pull on a plumb bob that would deflect the plumb bob from “vertical” toward the mountain range. They thus estimated the mass of the mountain range and then predicted how much the vertical deflection should be. To their surprise, they found that the mass was not deflected as far as they predicted – they thus postulated that a “deficit” of mass beneath the mountain range had to exist. The mass deficit was a buoyant crustal root that extended down into the denser surrounding mantle. Since the 18th century, many more gravity surveys of mountain ranges have been completed and they indicate that mountain ranges are often (but not always) accompanied by a mass deficit. For example, if one measures the gravitational attraction at many points in or above a mountain range and one then corrects the measured gravity signal for a variety of effects, one of which includes the contribution from topography above sea level (this is done by estimating the gravitational attraction that results from a given volume of material with a density equivalent to that of continental crust), the gravity field over a mountain range should be the same as the gravity field for flat regions that flank the mountain range. Instead, the corrected gravity field over the mountain range typically has values lower than the surrounding flat regions. This gravity “deficit” is evidence for a mass “deficit” beneath the mountain range – such a deficit can only occur if the density of material beneath the range is lower than the density of the material beneath the flat-lying regions. Thus, less dense or buoyant material underlies many mountains – this buoyant material is the “root” that is predicted to exist based on Archimede’s principle.

In Psalms 30:7 “O LORD, You favored me; You made my mountain stand strong. When You hid Your face, I was dismayed.

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