See other Science/Tech Articles
Title: Sun's rays to roast Earth as poles flip
Source:
[None]
URL Source: http://www.guardian.co.uk/world/2002/nov/10/science.research
Published: Oct 14, 2009
Author: Robin McKie
Post Date: 2009-10-14 16:07:07 by Horse
Keywords: None
Views: 172
Comments: 8
Earth's magnetic field - the force that protects us from deadly radiation bursts from outer space - is weakening dramatically. Scientists have discovered that its strength has dropped precipitously over the past two centuries and could disappear over the next 1,000 years. The effects could be catastrophic. Powerful radiation bursts, which normally never touch the atmosphere, would heat up its upper layers, triggering climatic disruption. Navigation and communication satellites, Earth's eyes and ears, would be destroyed and migrating animals left unable to navigate. 'Earth's magnetic field has disappeared many times before - as a prelude to our magnetic poles flipping over, when north becomes south and vice versa,' said Dr Alan Thomson of the British Geological Survey in Edinburgh. 'Reversals happen every 250,000 years or so, and as there has not been one for almost a million years, we are due one soon.' For more than 100 years, scientists have noted the strength of Earth's magnetic field has been declining, but have disagreed about interpretations. Some said its drop was a precursor to reversal, others argued it merely indicated some temporary variation in field strength has been occurring. But now Gauthier Hulot of the Paris Geophysical Institute has discovered Earth's magnetic field seems to be disappearing most alarmingly near the poles, a clear sign that a flip may soon take place. Using satellite measurements of field variations over the past 20 years, Hulot plotted the currents of molten iron that generate Earth's magnetism deep underground and spotted huge whorls near the poles. Hulot believes these vortices rotate in a direction that reinforces a reverse magnetic field, and as they grow and proliferate these eddies will weaken the dominant field: the first steps toward a new polarity, he says. And as Scientific American reports this week, this interpretation has now been backed up by computer simulation studies. How long a reversal might last is a matter of scientific controversy, however. Records of past events, embedded in iron minerals in ancient lava beds, show some can last for thousands of years - during which time the planet will have been exposed to batterings from solar radiation. On the other hand, other researchers say some flips may have lasted only a few weeks. Exactly what will happen when Earth's magnetic field disappears prior to its re-emergence in a reversed orientation is also difficult to assess. Compasses would point to the wrong pole - a minor inconvenience. More importantly, low-orbiting satellites would be exposed to electromagnetic batterings, wrecking them. In addition, many species of migrating animals and birds - from swallows to wildebeests - rely on innate abilities to track Earth's magnetic field. Their fates are impossible to gauge. As to humans, our greatest risk would come from intense solar radiation bursts. Normally these are contained by the planet's magnetic field in space. However, if it disappears, particle storms will start to batter the atmosphere. 'These solar particles can have profound effects,' said Dr Paul Murdin, of the Institute of Astronomy, Cambridge. 'On Mars, when its magnetic field failed permanently billions of years ago, it led to its atmosphere being boiled off. On Earth, it will heat up the upper atmosphere and send ripples round the world with enormous, unpredictable effects on the climate.' It is unlikely that humans could do much. Burrowing thousands of miles into solid rock to set things right would stretch the technological prowess of our descendants to bursting point, though such limitations do not worry film scriptwriters. Paramount's latest sci-fi thriller, The Core - directed by Englishman Jon Amiel, and starring Hilary Swank and Aaron Eckhart - depicts a world beset by just such a polar reversal, with radiation sweeping the planet. The solution, according to the film, to be released next year, involves scientists drilling into Earth's mantle to set off a nuclear blast that will halt the reversal. Given that temperatures at such depths rival those of the Sun's surface, such a task would seem impossible - except, of course, in Hollywood
Post Comment Private Reply Ignore Thread
Top • Page Up • Full Thread • Page Down • Bottom/Latest
#1. To: Horse (#0)
Scientists have discovered that its strength has dropped precipitously over the past two centuries and could disappear over the next 1,000 years. The effects could be catastrophic. Why should this be any concern? 0bama can fix this and win a preemptive Nobel for merely waving a hand at the heavens and wishing it not to be.
Losing my hair and now this, two things to worry about.
This is from 2002. With seven additional years of monitoring, I wonder what the status is today?
LATEST BULLETIN: WE'RE ALL GONNA DIE EVENTUALLY!!!
"It does not take a majority to prevail, but rather an irate, tireless minority, keen on setting brush fires of freedom in the minds of men." -- Samuel Adams (1722-1803)‡
This is not entirely new. Studies of the orientation of iron particles in ancient clay and such show that the poles have changed before - North was South perhaps fifteen thousand years ago. The poles peak in their magnetic power (all the iron particles line up), then gradually weaken (most but not all the particles line up) and then, briefly seem not to have any power (particles are in random orientation), and then strengthen again only this time the directions are reversed. At the moment the poles are past their peak, so they are gradually weakening and will eventually reverse. They'll be down to zero in about four thousand years -- it will be a Thursday. So four thousand years from now you'll have to throw out your Boy Scout compass.
I don't have any current numbers but from what I am aware of the earth's magnetic field has continued to slowly decline in strength. We do know that poles do flip from time to time. That was recorded, (first discovered during the International Geophysical year in '57-'58) in the magnetic polarization of the cooled magma upwelling through the Mid-Atlantic Rift. This was the same "Seafloor Spreading" which validated "Continental Drift" now known as "Plate Tectonics" (the name change was probably to cover up the embarassment of having called Alfred Wegner a Kook and Idiot who should stick to his own field - he put forth the theory in the early part of the 20th Century). So, that the Poles do shift is a validated fact. The question is not "IF" but "WHEN"?
"An education isn't how much you have committed to memory, or even how much you know. It's being able to differentiate between what you know and what you don't. ~ Anatole France
Don't worry Horse. Congress will pass a law making it illegal for the magnetic poles to flip and all will be well.
"The Central Intelligence Agency owns everyone of any significance in the major media." ~ William Colby, Director, CIA 1973–1976 The purpose of the legal system is to protect the elites from the wrath of those they plunder.- ghostdogtxn and Elliott Jackalope "When plunder becomes a way of life for a group of men living together in society, they create for themselves in the course of time a legal system that authorizes it and a moral code that justifies it." - Frederic Bastiat
Earth's magnetic field - the force that protects us from deadly radiation bursts from outer space - is weakening dramatically.
#2. To: Horse (#0)
#3. To: Horse (#0)
#4. To: Mr Nuke Buzzcut (#3)
This is from 2002. With seven additional years of monitoring, I wonder what the status is today?
#5. To: Horse (#0)
#6. To: Horse (#0)
#7. To: Mr Nuke Buzzcut (#3)
This is from 2002. With seven additional years of monitoring, I wonder what the status is today?
#8. To: Horse (#0)
Top • Page Up • Full Thread • Page Down • Bottom/Latest