Topic: Earth losing it's magnetism (Read 8021 times)

Rat_Boy · « **on:** December 12, 2003, 09:37:57 am »

From CNN

Well, that'll mess up the compass industry.

JMM · « **Reply #1 on:** December 12, 2003, 09:41:21 am »

Thank God for GPS!

WaterTiger · « **Reply #2 on:** December 12, 2003, 09:53:23 am »

It happened before ...

From the article:

Quote:

At that rate of decline, the field could vanish altogether in 1,500 to 2,000 years, said Jeremy Bloxham of Harvard University.

Hundreds of years could pass before a flip-flopped field returned to where it was 780,000 years ago. But scientists at a meeting of the American Geophysical Union cautioned that scenario is an unlikely one.

Some theorize it launched the Metazoic era.

This book touches on some of these fascinating topics ...

Integration

Stormbringer will go nuts on this topic, don't get him started ... I can hear him typing now.

WaterTiger

hobbesmaster · « **Reply #3 on:** December 12, 2003, 10:45:53 am »

It looks like the field will just do a reversal, those are actually quite common geologically; the way to tell how old the ocean floor is at a given spot is to see how many reversals its gone through.

Stormbringer · « **Reply #13 on:** December 12, 2003, 03:18:01 pm »

At it's worst the southern ozone hole actually exposed part of Ausie land to unfiltered UV. Ozone is electrically charged so it likely is affected by the magnetosphere. Exactly how and how much I'm not sure. But the magnetic field reverses itself cyclicly in gelogic time. And as it switches direction there iss a brief period where it is nuetralized by equal alignments of forward and reversed magnetic domains in the geological strata. The variance over time results in grid north and magnetic north not agreeing to greater or lesser degrees. At the bottom of all military maps is a declination diagram which is a conversion factor to add or subtract in order to realine compass readings with grid north. But because that alignment changes overtimes older maps declination diagrams will not be correct for the present conversion factor. This is becaise as the plastic mantle lays down new layers under the old the domain alignment changes with currents in the molten material.

JMM · « **Reply #14 on:** December 12, 2003, 03:27:45 pm »

Also Napster is back!

Stormbringer · « **Reply #15 on:** December 12, 2003, 03:33:40 pm »

There is a procedure for determining the current declination in any area by dialing in the correct azimuth to a known point from a known point then turning using record motion to magnetic north the new value on the dial will be the declination constant though the procedure is normally repeated several times using a succession of several known points and taking the mean reading if they agree to within half a mil. A mill is .05625 degrees. a degree is 17.7- mils.

IntgrSpin · « **Reply #16 on:** December 12, 2003, 08:28:27 pm »

Hey look at it this way...

If it flips, the north pole will actually be up north again.

Rat_Boy · « **Reply #17 on:** December 12, 2003, 09:37:57 am »

From CNN

Well, that'll mess up the compass industry.

JMM · « **Reply #18 on:** December 12, 2003, 09:41:21 am »

Thank God for GPS!

hobbesmaster · « **Reply #20 on:** December 12, 2003, 10:45:53 am »

It looks like the field will just do a reversal, those are actually quite common geologically; the way to tell how old the ocean floor is at a given spot is to see how many reversals its gone through.

Stormbringer · « **Reply #30 on:** December 12, 2003, 03:18:01 pm »

At it's worst the southern ozone hole actually exposed part of Ausie land to unfiltered UV. Ozone is electrically charged so it likely is affected by the magnetosphere. Exactly how and how much I'm not sure. But the magnetic field reverses itself cyclicly in gelogic time. And as it switches direction there iss a brief period where it is nuetralized by equal alignments of forward and reversed magnetic domains in the geological strata. The variance over time results in grid north and magnetic north not agreeing to greater or lesser degrees. At the bottom of all military maps is a declination diagram which is a conversion factor to add or subtract in order to realine compass readings with grid north. But because that alignment changes overtimes older maps declination diagrams will not be correct for the present conversion factor. This is becaise as the plastic mantle lays down new layers under the old the domain alignment changes with currents in the molten material.

JMM · « **Reply #31 on:** December 12, 2003, 03:27:45 pm »

Also Napster is back!

Stormbringer · « **Reply #32 on:** December 12, 2003, 03:33:40 pm »

There is a procedure for determining the current declination in any area by dialing in the correct azimuth to a known point from a known point then turning using record motion to magnetic north the new value on the dial will be the declination constant though the procedure is normally repeated several times using a succession of several known points and taking the mean reading if they agree to within half a mil. A mill is .05625 degrees. a degree is 17.7- mils.

IntgrSpin · « **Reply #33 on:** December 12, 2003, 08:28:27 pm »

Hey look at it this way...

If it flips, the north pole will actually be up north again.

Rat_Boy · « **Reply #34 on:** December 12, 2003, 09:37:57 am »

From CNN

Well, that'll mess up the compass industry.

JMM · « **Reply #35 on:** December 12, 2003, 09:41:21 am »

Thank God for GPS!

hobbesmaster · « **Reply #37 on:** December 12, 2003, 10:45:53 am »

It looks like the field will just do a reversal, those are actually quite common geologically; the way to tell how old the ocean floor is at a given spot is to see how many reversals its gone through.

Stormbringer · « **Reply #47 on:** December 12, 2003, 03:18:01 pm »

At it's worst the southern ozone hole actually exposed part of Ausie land to unfiltered UV. Ozone is electrically charged so it likely is affected by the magnetosphere. Exactly how and how much I'm not sure. But the magnetic field reverses itself cyclicly in gelogic time. And as it switches direction there iss a brief period where it is nuetralized by equal alignments of forward and reversed magnetic domains in the geological strata. The variance over time results in grid north and magnetic north not agreeing to greater or lesser degrees. At the bottom of all military maps is a declination diagram which is a conversion factor to add or subtract in order to realine compass readings with grid north. But because that alignment changes overtimes older maps declination diagrams will not be correct for the present conversion factor. This is becaise as the plastic mantle lays down new layers under the old the domain alignment changes with currents in the molten material.

JMM · « **Reply #48 on:** December 12, 2003, 03:27:45 pm »

Also Napster is back!

Stormbringer · « **Reply #49 on:** December 12, 2003, 03:33:40 pm »

There is a procedure for determining the current declination in any area by dialing in the correct azimuth to a known point from a known point then turning using record motion to magnetic north the new value on the dial will be the declination constant though the procedure is normally repeated several times using a succession of several known points and taking the mean reading if they agree to within half a mil. A mill is .05625 degrees. a degree is 17.7- mils.

IntgrSpin · « **Reply #50 on:** December 12, 2003, 08:28:27 pm »

Hey look at it this way...

If it flips, the north pole will actually be up north again.

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