Earth's magnetic fields

[Squidman]

The following is only loosely related to cephalopods, as it is about their most famous predator.

I read that sperm whales appear to strand on beaches that run perpendicular to Earth's magnetic fields. I cannot find the maps neccesary to support this theory, however. If anyone can give me input, I would not be bored for several weeks.

 

[Fujisawas Sake]

Yo Squidman, wazup?

I'm not exactly sold on this. According to my oceanography texts the Earth's magnetic field shifts a lot... perhaps as many as every few hundred thousand years... with no apparent correlation to mass extinctions. I doubt whales are stupid enough to beach themselves due to magnetism only. Such an issue would have probably led to extinction many aeons ago.

Then again, anything's possible. Has there been any recordings of mass strandings before the modern era? If there weren't any, maybe it does have to do with E.L.F.-band radio experiments or something like that.

John

 

[Steve O'Shea]

John, I think it has something to do with modern 'Merican programming standards; the whales just can't take it anymore and prefer to beach!

I'm not familiar with the theory Squidman - can you tell us a little more?

 

[Squidman]

Improbable theory

Alas, I have only read a very brief version of this theory, so I cannot tell you more. Maybye I should look up more probable theories...

 

[spartacus]

Prof. Squidman, currently the magnetic poles (North is at least) are on a bit of a walkabout & accelerating. As this is the case then, as a non soap opera watcher, it would not be to assume the magnetic field as a whole is shifting therefore possibly causing some confusion to organisms that may be reliant on it for navigation.
The above is pure theorising on my part from data gleaned elsewhere, but in a universe where sense is only made where chaos rules then NOTHING is impossible except Phil getting a round in !

soon your brain will be too big for your head & start to leak out of your ears but do not panic ! I repeat, do not panic as this is normal for TONMO peeps !

Keef

 

[cthulhu77]

Ah yes...the "Heibermann" theory...the wobble of the earth finally reaching that penultimate swing, and then the angles change!!!! Bang!
Topsy turvy goes the globe...
but at least we know whales get the bends, too....

 

[main_board]

I thought i've been taught in some geography class that the earth's magnetic field does change (though I'm not sure how often) due to the fact that the inner layers, chiefly the mantle, are liquid (well actually only the mantle is a true liquid so...Wow its fun to remember stuff.) Because of the spin of the earth, the liquid mantle shifts and slides around underneih the crust and above the next layer, which is a little thicker liquid. Due to the uneven composition and distibution of various metals (persumably iron, nickel and the like) in the mantle, they create changing magnetic fields which ultimately find their way out to the surface effecting our poor lil' creatures.

No, as to whether or not fields affect whales: I don't see why not. It makes sense so far. I'm sure its not the be all to end all and that it is probably just a factor, but I'm sure it does contribute some.

That's all from me. If I post following this post, its prolly cause I went and fact checked what I just said and found it to be erroneous.

 

[main_board]

Hey! Who called this one?!?! I'm back with more, and with references so that I don't look completely out of line. So, here goes:

Convection: the word I was looking for. Convections is the motion of molten rock starting deeper in the earth. It is hotter and less dense so it rises to the surface. As it does so, it cools and gets more dense, and therefore sinks back down. This creates a sort of cyclic cycle (thats repetetive). When convection occurs in the earth's layers, the material being moved around is full of metals (being iron and nickel) and this motion creates electric currents and charges, which also create magnetic fields. This whole thing is called the DYNAMO EFFECT (I suggest searching the web using that term for more info.).

The earths magnetic field itself is a magnetic dipole, with one near the geographic north and the other south.The location of the magnetic poles is not static but wanders as much as several miles a year. The two poles wander independently of each other and are not at exact opposite positions on the globe.

Other points on the field: 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. It is believed that this last occurred some 780,000 years ago, referred to as the Brunhes-Matuyama reversal.

Interesting (and potentially scary) note: At present, the overall geomagnetic field is becoming weaker at a rate which would, if it continues, cause the field to disappear, albeit temporarily, by about 4000 AD.1 Other sources have put the date of field collapse as early as 3000 AD. The deterioration began roughly 150 years ago and has accelerated in the past several years. So far the strength of the earth's field has decreased by 10 to 15 percent. However, one should note that no one knows if field decay will continue in the future. Also, since a magnetic field reversal has never been observed by humans and the mechanism of field generation is not well understood, it is difficult to say what the characteristics of the magnetic field might be leading up to such a reversal.

Well, you wanted not to be bored for a week and I do think you have enough now just to read, never-the-less understand and preform more research. A most interesting site, and one which I eventually just copy and pasted to save time: Earth's magnetic field - Wikipedia

Hope I didn't include too much useless info as this was about whales and squid and I have completely ignored that. Enjoy!

 

[Architeuthoceras]

Geomagnetic Time Scale

The black and white bars show times of reversed magnetic fields