It ain’t what it used to be:
The Federal Aviation Administration required the runway designation change (at Tampa International Airport) to account for what a National Geographic News report described as a gradual shift of the Earth’s magnetic pole at nearly 40 miles a year toward Russia because of magnetic changes in the core of the planet.
For the non-aviators in the crowd, airport runways are painted on the approach with an abbreviated magnetic heading. Thus, a runway oriented to the west (270 degrees magnetic) would be called Runway 27. Only now, it will be called runway 28 at Tampa International. Because the Earth’s magnetic pole is moving at 40 MPH miles per year (oops). Towards Russia.
Which, for some surprising reason, wigs me out just a little.
It was only today that I learned that the Earth’s magnetic field has on occasion actually flipped. I’m not sure I wanted to know that could happen.
Just as long as we HAVE one. That solar wind can be pretty nasty. It didn’t do Mars any good.
I veiw this issue lioke something that the Ghostbusters would handle…They would be there to advise our leaders…
Dr. Peter Venkman: Our Country is headed for a disaster of biblical proportions.
President: What do you mean, “biblical”?
Dr Ray Stantz: What he means is Old Testament, Mr. President, real wrath of God type stuff.
Dr. Peter Venkman: Exactly.
Dr Ray Stantz: Fire and brimstone coming down from the skies! Rivers and seas boiling!
Dr. Egon Spengler: Forty years of darkness! Earthquakes, volcanoes…
Winston Zeddemore: The dead rising from the grave!
Dr. Peter Venkman: Human sacrifice, dogs and cats living together… mass hysteria!
President: All right, all right! I get the point…
Or maybe not….
True North moves around a bit too, but it’s usually transparent to the user, unless you have requirements like NRL or NASA do.
The locations of the magnetic poles has always moved. The dynamo that the iron core of the Earth creates as it spins does not have the same axis as the Earth’s crust (true North/South) and it’s moving around in there. Always has. And, yes, it can flip and has on a few occasions. Which, as you note, is not such a good thing for living organisms sensitive to solar radiation, especially of the atomic particulate kind.
Geologists have seen several hundred pole reversals from core samples taken on each side of the Mid-Atlantic Ridge.
Not only does the geologic record show a number of reversals, but there seems to also be a relationship between reversals and glaciations. It isn’t yet clear if one causes the other or there is a single trigger for both. The mechanism for geomagnetic reversals isn’t known. We just know that they happen, and seem to happen almost instantly, in geologic terms.
It also seems that the Earths magnetic field has been weakening for the past 150 years or so. Are we maybe heading for a reversal in the very new future?
As you noted, these reversals happen in geological time, which from the research I’ve seen takes from several hundred to several thousand years to occur. Plenty of time to sticky-note our compasses I’d say.
Some things in the geologic record indicate that it may indeed happen almost literally overnight. Hard to say though, since there has never been anyone around to witness one. A day? A week? A year? Time will tell.
Here-here. One of things which helps me keep things in perspective is that despite all our advances, there is so very much that we just don’t know. If I ponder it even a little I’m struck with a sense that we’re out very far on the edges, getting both educated and lucky glimpses from time to time.
One of those universe shows on the tube recently was talking about the eventual death of the stars in a bunch of trillions of years. It drew a snort to say the least. I’m grateful for today and trying to take care of tomorrow’s agenda. “several trillion years”, indeed.
(star)dust in the wind, and very lucky to be here, now. Peace.
I asked a biologist that I work with how this could/might affect the migration of birds, got a “thats a question” for a answer.
when I was on the Navy Staff, everyone in my office got a self-published book by a very old retired Navy Capt. which discussed magnetic pole inversions and predicted death and destruction as a result. It was appropriately filed.
I read a Clive Custler book a few years back about terrorists trying to cause a magnetic pole reversal. I know, it’s a book of fiction, but I figure he had to do SOME kind of research as to what it would do. Didn’t sound good, if I recall. Scary, kinda.
Yeah, towards Russia is wiggy. I thought the same thing when I read that. Blech.
Also, for are y’all smarter than me, could a reversal cause… this whole global warming thing that so many believe is happening?
No idea, but I remember thinking that if a scientist could plausibly attribute the weakening in the Earth’s magnetic field to some profitable human activity, preferably one practiced disproportionately by America, we’d have our next scare. Stop the weakening! (Before it’s too late.)
I remember when they changed the rwy designation at Norton AFB, back in the 70s when I was stationed there in the old Starlizard. I took off from Rwy 05 for an overnight trip. Landed back at Norton the next day and was “cleared to land Rwy 06″……weird feeling, for sure.
As far as I can tell the New York Times will use this movement of the magnetic North Pole to claim that it’s all global warming’s fault.
It’s gotta be Bush’s fault.
@Lex Apparently you don’t listen to Coast-to-Coast AM on KOGO. That’s on their semi-regular list of improbably things we need to worry about NOW!
George Nory is never wrong about these things!
Or Art Bell before him. Heard him a few weekends ago subbing from Manila.
Or KFI640AM in LA, Kevin.
You listen to Art Bell?
Most charts that show magvar will also show an annual rate and direction. It’s fairly predictable. The magnetic heading of the Tampa runways just happened to tick over the rounding factor, what with runways only being numbered to the nearest 10 degree tick. The news article is noteworthy (to aviators) mainly in it’s uncommon lack of hysteria. I’m reminded of a BBC report some years back when the Blonde Talking Head was interviewing an astronomer, who revealed that the our galaxy would collide with another— some billions of years hence. Her question? “What is Government doing about it?”
And movement of the magnetic pole towards Russia (and away from us) is a good thing, seeing as how mag compasses are notoriously unreliable in the vicinity of the magnetic poles. Let them deal with huge variation.
That reminds me of a question WTVF (Channel 5, Nashville, TN) asked of the State Adjutant General back in the 80s.
“General, are you watching any potential terrorists in theh state?” He replies, “Well miss news babe, there are several in teh state and we are keeping a close eye on them.”
I had to laugh as the National Guard had no such function; the AG knew it, but gave a nice political answer to satisfy the news babe.
Our good host is slipping a bit. The article says the shift is occurring at a rate of 40 miles per YEAR, and he said he is worried because it is moving at 40 MPH.
Units matter!
For a period of about 30 years the location of the north mag pole was not known. They could measure variation (declination for the Army types), as well as the secular change in the variation.
The movement of the mag pole does seem to be accelerating. The reason is unknown, but the rate of change is not stable or fixed. The change posted on charts is a best guess estimate of the secular change.
USGS has a number of geomagnetic observatories, and info on them can be found at
http://geomag.usgs.gov/
if you want to read more about it.
NOAA has a declination calculator at
http://www.ngdc.noaa.gov/geomagmodels/Declination.jsp
There are some papers at the USGS site about geomagnetism as well.
On a unrelated note, MacDill Air fest is traditionally held in March. The Blue Angles, and the Thunderbirds were both unavailable.
So we are having it in November this year.
The signature of the periodic reversal of the magnetic field of the Earth that is found on both sides of the mid-Atlantic ridge was one of the strongest indications of continental drift and the opening of the Atlantic Ocean in the late Triassic Period.
Sorry TIA (Tampa International Airport) and MacDill are kind of close. Not related except geographically.
We tried very hard back in the sixties to move magnetic north a little to the west. Our method included leaving a lot of iron just west of Hanoi and other scenic places in package six.
Presumably all the highly electrically conductive but magnetically inert aluminum we sprinkled in the same vicinity made controlling the variables in the experiment impractical by inducing electromechanical effects with unpredictable emf vectors that disrupted the placement of the alignment of the magnetic poles whose vector sum’s alignment was the key to the cunning plan behind it all.
Greater research is required to resolve the data ambiguities (Don’t be alarmed, all the papers say that, you can’t get a grant without one).
Actually, the terrestrial magnetic field modelers predict a ~200 year interregnum between pole flips, where things get rather strange — instead of just 2 poles (N/S), there would be periods of 4 or even 8 poles. Since you still have the same amount of magnetic *power* to work with, this would make the overall field weaker and prone to holes during nasty solar events. I’m voting against a pole flip until we get the faster-than-light drive working
Oh, and the migratory critters? Unless they get maps they are toast.
I thought if and when it flips totally WE’RE toast too. Haven’t all pole flips been accompanied by mass extinctions?
Don’t think so. Reversals aren’t instant, though on a geological timescale they appear to be.
When people think of the earth magnetic field, they usually think of a homogeneous field as you’d get using a highschool lab experiment.
It’s not however, the field is spotty and has areas of different strength and polarity all over the place (these of course have some indicators on aviation charts, and are relevant to anyone relying on compasses).
These areas are neither stationary nor of fixed strenght. By plotting them over a period of years, scientists are finding that areas of reverse polarity are expanding and flowing together. Eventually this probably (it’s never been observed in progress of course) will cause enough strain on the polarity of the planet as a whole that there will indeed be a near instant flip, and we seem to be moving towards such a situation.
It’s an interesting idea, and would have profound effects on the radiation belts circling the planet, protecting it from solar wind and other nastiness, at least for a while.
Mass extinctions? Unlikely. Species going extinct while others mutate? Far more likely. But nothing on the scale of the dinosaurs.
Most likely is that Al Gore will blame CO2 while Obama blames Bush and Kos blames Halliburton.
Somewhere in Siberia a strange little man who answers the phone as “Peggy”, cranks up the voltage on the world’s largest super-magnet.
Thank you oldskydog!
That was a superb comment — I just love the advertisement series featuring “Peggy”.
That was a funny commercial.
Who wrote this? They can’t be telling the Liberal Arts majors about these natural phenomena. It’ll get them all at sea over a natural world that is not all clockwork and controllable. One that ebbs and flows constantly changing without so much as a by your leave to their Ivy league education. Magnetic north moves 40 km a year. No one tell them about the diurnal movement that can be 80 km from the mean. Think of the polar bears , the horror. Someday we’ll explain time to them. GMT, UTC, zone time, LMT, LAT, leap seconds. So many times, so much uncertainty in the mico. And that is before we get to Homeland Security’s 364 day work year.
LOL!
“Because the Earth’s magnetic pole is moving at 40 MPH miles per year (oops). Towards Russia.”
Just another datum in a long list of evidence of Russia sucking.
Lex,
If you look at the tectonic plates, the tell tale data point for tectonic spread was the magnetic signatures being symetric on the mid Atlantic ridge showing that geologically, over time, it was symmetrically spreading from the ridge and going back under in the subduction zone. I think one of my geo profs said that it typically takes on the order of about 10k years for this change to occur. I never rally looked into it beyond that.
Thank god for GPS
Its a slow/lazy day here in paradise…so I dutifully read each and every one of the forty +/- occasionally intelligent, often comic and clearly exhaustive comments to this post…
… accordingly I have nothing to add to the discussion except the admonition that ” a little knowledge is a dangerous thing” and that old saw and my refuge… “ignorance is bliss”…Best
Damn that Global Warm strikes again.
OK, Russia can keep the North Pole and Santa and all his elves as long as we get more oil to drive our SUV’s to the WALMART and buy more stuff and tilt the earth back to our side!
Well, poo! I managed to make it to Eagle Scout without learning how to convert from magnetic to true, because I’ve always lived where the difference was too small to read on a pocket compass. But dang! Tampa is near by! Lessee now, “East is least, and West is best…”
P.s. Sign conventions have always given me _lots_ of trouble. Remember that scene in “Starman Jones”, in which the astrogator applies a whopping last-minute correction to the hyperspace jump, with the WRONG SIGN? Yep, I always fear doing something like that.
You don’t work for JPL by any chance, do you? (Grin)
Oh, the Mars thing! Nah, I usedta work for NASA at Marshall in the early seventies, but was just a co-op and not allowed to do anything potentially dangerous. (mostly sweeping the lab and using a primitive calculator to reduce data)
There’s an old mnemonic device that comes from “True Virgins Make Dull Company.” T=true, V=variation, M=magnetic, D=deviation, C=compass. On a ship you have deviation which is caused by the steel hull. You swing ship to adjust the steel spheres you see on a binnacle to minimize deviation, and then record the deviation as it will vary according to the heading.
Anyway, if you are on land, you can stop at magnetic since you have no deviation to worry about (except for the odd ‘Nam vet carrying that mortar fragment in his chest) so compass=magnetic. You add west variation (declination) and subtract east to get the true direction. On USGS maps, the declination is found in the marginal info at the bottom of teh sheet.
There’s a Wikipedia article which confuses the hell out of me, because it talks about different people pointing the sign convention in different ways. Can somebody point me to a USN Quartermaster tutorial on the subject, with problems, and worked examples?
This is why I follow roads (and rivers) when flying.
Earth’s magnetic fields change on a regular basis (alternating through zero on their way) and since the strength of the field is what keeps the majority of the sun’s deadly radiation away it’s easier to understand how evolution seems sporadic and nonlinear and how fair-skinned folks better buy a big hat and umbrella or two-
It seems very logical to me that a weakening of such a field would thus increase the amount of energy reaching earth’s surface and then lead to warming, if any is actually occuring. Or maybe it’s too many monster truck rallies-
I’m bettin’ on the monster trucks..