2007-04-11 15:28:19 · 4 answers · asked by ? 6 in Science & Mathematics ➔ Earth Sciences & Geology
It is when the Earth's magnetic field reverses polarity: Right now the Earth's geographic north pole is the magnetic south, when the geographic north becomes the magnetic north, the poles will have reversed. This happens fairly regualrly in intervals of 150,000 years or so, but the last one occurred 780,000 years ago, so we are due for one. Some speculate that a reversal has started because ever since the strength of earth's magnetic field was first mesured by Gauss in 1837, it has declined in strength 7-10%. We won't see the reversal happen in our life time as it can take 1000 yrs for a full reversal to happen.
2007-04-12 06:07:30 · answer #1 · answered by xericia 2 · 5⤊ 0⤋
The magnetic fields of the earth switch . The compass will read opposite. No big deal. Magnetic rock found in the earth shows this has happened numerous times in the past, and is past due. The compass actually doesn't point north, But about 8 degrees from north pole where the northern flux line breaks out of the earth's mantle.This magnetic flux is what draws the Sun's solar storms to the poles and neutralizes them at the poles and causes ths Aurora Borealis, or Northern Lights. This saves the earth from deadly solar radiation, The earth's magnetic field is genegated by the earth's iron core.
2007-04-11 23:03:16 · answer #2 · answered by Jackolantern 7 · 1⤊ 0⤋
The magnetism of the north and south poles swap. Believe it or not, it happens, and on a fairly regular basis. For some reason 15,000 years comes to mind, but I might be off by an order of magnitude.
North wasn't always north (not that it really matters in space, anyways).
2007-04-11 22:36:09 · answer #3 · answered by T J 6 · 0⤊ 0⤋
where the north and south poles would change places. the needle of a compass would point south then.
2007-04-11 22:31:17 · answer #4 · answered by gonavy271 2 · 0⤊ 1⤋