2007-12-10 07:57:58 · 10 answers · asked by Stannnn 3 in Science & Mathematics ➔ Earth Sciences & Geology
The earth's magnetic field strength was measured by Carl Friedrich Gauss in 1835 and has been repeatedly measured since then, showing a relative decay of about 5% over the last 150 years
http://en.wikipedia.org/wiki/Earth%27s_magnetic_field
2007-12-10 08:32:24 · update #1
The Earth's magnetic field is seen as roughly a magnetic dipole, with one pole near the north pole and the other near the south pole. Magnetic fields extend infinitely, although they are weaker further from their source. The Earth's magnetic field, which extends several tens of thousands of milesinto space, is called the magnetosphere.
The Earth's magnetic field is constantly changing in size and position. The two poles wander independently of each other and are not at directly opposite positions. Currently the magnetic south pole is farther from the geographic south pole than the magnetic north pole is from the geographic north pole.
The strength of the field at the Earth's surface ranges from less than 30 microteslas in an area including most of South America and South Africa to over 60 microteslas around the magnetic poles in northern Canada and south Australia and in part of Siberia.
It has been proposed that the Earth's magnetic field reverses at intervals, ranging from tens of thousands to many millions of years, with an average interval of approximately 250,000 years. The last such event is thought to have occurred some 780,000 years ago.
Frequently, the Earth's magnetosphere is hit by solar flares causing geomagnetic storms, which result in displays of aurorae. The short-term instability of the magnetic field is caused by these storms. However, the magnetic field itself is not decaying. This can only happen in one of two ways.
Either the Earth has a catastrophe of unimaginable proportions and dies in some manner so that the inner iron core, the cause of the magnetism, is no longer functioning, or the sun explodes sufficiently that it destroys the Earth.
2007-12-10 08:26:41 · answer #1 · answered by William Tells 5 · 0⤊ 0⤋
effortlessly. The magazine container of the planet has replaced direction countless circumstances. throughout the substitute in direction, the sphere weakens yet would not completely disappear. additionally in this variation, there is extra suitable than one north magnetic pole and extra suitable than one south magnetic pole. the area of the magnetic poles isn't completely related to the area of the geographic poles. The magazine container is known to be created by ability of currents interior the fluid iron interior the outer center of the planet. because of the fact the Moon and Mars have not any significant magnetic fields, that's known that their cores have solidified. that's consistent with the indisputable fact that they are the two significantly smaller than the Earth, had subsequently much less warmth to start with and have additionally cooled extra directly because of the fact of their smaller length.
2016-10-01 07:41:39 · answer #2 · answered by ? 4 · 0⤊ 0⤋
The field is not decaying it is just drifting around, this is inevitable because it is caused by complex patterns of fluid flow and magnetic fields in the Earths core. Sometimes it increases and sometimes it decreases sometimes it even reverses direction - there are loads of examples of this happening recorded in the magnetism of rocks.
Summary, it will not completely decay away.
2007-12-10 11:44:52 · answer #3 · answered by m.paley 3 · 1⤊ 0⤋
It won't until the earth cools to the point that there is no longer a liquid core, but we are due a reversal so watch out it'll confuse the pigeons!
2007-12-11 03:05:06 · answer #4 · answered by Anonymous · 1⤊ 0⤋
It's not.
The field is generated by currents in the liquid iron outer core of the earth.
2007-12-10 08:20:07 · answer #5 · answered by Wayner 7 · 2⤊ 0⤋
The old ley line power grid is virtually shut down altogether now and the earth is getting ready for its next transition,global cleansing.And so the mills grind on-----
2007-12-10 08:03:23 · answer #6 · answered by Anonymous · 0⤊ 2⤋
Who says it is decaying?
2007-12-10 08:01:26 · answer #7 · answered by Lucky Man 2 7 · 0⤊ 1⤋
It is indeed decaying - and this is one of many good evidences that the earth is young, not old.
http://www.creationontheweb.com/content/view/760
Not sure how long it would take to decay to an immeasurable level - probably tens of thousands of years.
2007-12-10 08:10:50 · answer #8 · answered by a Real Truthseeker 7 · 1⤊ 5⤋
IT WILL NEVER HAPPEN STATIC ELECTRICITY AND SOLAR WIND KEEP EVERYTHING IN TIPTOP SHAPE.
2007-12-10 08:20:27 · answer #9 · answered by Loren S 7 · 1⤊ 0⤋
Not long to go now. :-(
2007-12-10 08:01:09 · answer #10 · answered by Giselle is Well 3 · 0⤊ 3⤋