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Related: About this forumWhy Scientists Think Earth's Magnetic Poles Are About to Flip
Why Scientists Think Earth's Magnetic Poles Are About to Flip
The Earth is blanketed by a magnetic field. It's what makes compasses point north, and protects our atmosphere from continual bombardment from space by charged particles such as protons. Without a magnetic field, our atmosphere would slowly be stripped away by harmful radiation, and life would almost certainly not exist as it does today.
You might imagine the magnetic field is a timeless, constant aspect of life on Earth, and to some extent you would be right. But Earth's magnetic field actually does change. Every so often on the order of several hundred thousand years or so the magnetic field has flipped. North has pointed south, and vice versa. And when the field flips it also tends to become very weak.
What currently has geophysicists like us abuzz is the realization that the strength of Earth's magnetic field has been decreasing for the last 160 years at an alarming rate. This collapse is centered in a huge expanse of the Southern Hemisphere, extending from Zimbabwe to Chile, known as the South Atlantic Anomaly. The magnetic field strength is so weak there that it's a hazard for satellites that orbit above the region the field no longer protects them from radiation which interferes with satellite electronics.
And the field is continuing to grow weaker, potentially portending even more dramatic events, including a global reversal of the magnetic poles. Such a major change would affect our navigation systems, as well as the transmission of electricity. The spectacle of the northern lights might appear at different latitudes. And because more radiation would reach Earth's surface under very low field strengths during a global reversal, it also might affect rates of cancer.
Read more: http://www.livescience.com/57778-clues-earth-magnetic-poles-will-flip.html
tblue37
(65,211 posts)democratisphere
(17,235 posts)After what we have done to her, I don't blame her.
applegrove
(118,434 posts)Man has cried a billion tears
For what he never knew,
Now Man's reign is through..."
democratisphere
(17,235 posts)We'll be lucky to make it to the end of this century. We need an alternative planet quickly.
lastlib
(23,118 posts)Until we get one, I can oly say, God help this planet.
democratisphere
(17,235 posts)Rollinrock
(4 posts)The flip occurs about every 700,000 years. We know this because volcanic rocks store a permanent record of the direction of their magnitism when they harden. The anomaly refered to is the field flipping. It switches slowly on our time scale and as this is happening it gets patchy and weak as described, eventually changing poles, at least in that area. A map of the magnetic field will show these patches around the globe, more notable near equatorial regions. The direction of the polarity makes no difference or little difference and might be noticeable visually in the borealas effect changing a bit because the electrons and particles go the opposite direction. I'm no authority by the way. Other effects noted are radio interference, higher radiation due to weak magnetic field., effects related to slightly elevated radiation in a given area.
These effects are normal and in most cases will cause little inconvenience in the average persons day.
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