Please create an account to participate in the Slashdot moderation system


Forgot your password?
Earth Transportation Science

Magnetic Pole Shift Affects Tampa Airport 317

RFSSystems writes "I thought this was an amazing and rather rare phenomenon and wanted to share. 'The airport has closed its primary runway until Jan. 13 to repaint the numeric designators at each end and change taxiway signage to account for the shift in location of the Earth's magnetic north pole.' It appears that the shifting poles have begun to affect air travel in a somewhat modest way. Could this also be the explanation for the falling/dead birds this week?" I hope the gradualists are right, but scenarios for rapid magnetic pole shift are fun to think about.
This discussion has been archived. No new comments can be posted.

Magnetic Pole Shift Affects Tampa Airport

Comments Filter:
  • Happens all the time (Score:5, Informative)

    by Anonymous Coward on Thursday January 06, 2011 @03:47PM (#34781394)

    The airport I work at has a second set of signage from when the gradual shift occurs in cycles, making for a 10 degree change in the direction of the runway. Ie, here it will be runway 10-28 becoming runway 09-27. Has nothing to do with birds, happens every decade or so. Ten years after that, itll be back to what it is now.

    • by jafiwam ( 310805 )

      AFAIK the pole is heading off to a different direction this time.

      It does wanter, and is "cyclic" in that it wanders all the time enough that it comes back to the same spot.

      Anybody thinking they are going to predict it however is mistaken or at best, lucky if they guess right.

      • by sjames ( 1099 )

        It's not a perfect pattern, but mostly it wanders within a circular region. Since the signage only has to change when it wanders far enough to one side to make a significant difference, it will naturally require a small set of alternate signs which will be reusable under typical conditions.

    • by RKBA ( 622932 )
      I am astounded they would be orienting runways according to the magnetic poles and not the "true" cardinal directions.
      • by nedlohs ( 1335013 ) on Thursday January 06, 2011 @04:57PM (#34782550)

        because measuring "true" cardinal directions is so simple, compared with measuring magnetic north.

        Oh wait...

      • by WuphonsReach ( 684551 ) on Thursday January 06, 2011 @04:58PM (#34782552)
        I am astounded they would be orienting runways according to the magnetic poles and not the "true" cardinal directions.

        Maybe because a magnetic compass will (almost) always work when the more advanced instruments don't?

        How do you propose that pilots figure out what the "true" cardinal direction is as they approach the airport? While working through their landing checklist, monitoring other air traffic, weather, and everything else that has to happen before the wheels touch down?

        I guarantee they don't have time to do a star-sighting.
        • INS systems on most aircraft already due true heading and magnetic. The problem is that most itty bitty, tiny hobbyist planes don't....But my smartphone does. I can't see the technology being that far out of reach for most aircraft owners. At this point, it's more about inertia, and how big such a change would be (manuals rewritten, all airports changed, etc).
          • And your smartphone software is compliant with DO178? And your smartphone is JAA certified? What model is that?
          • by icebike ( 68054 )

            Its nothing at all to do with inertia.

            It has a lot to do with a compass working long after your smartphone gave up because it ran out of battery, couldn't see any satellites, couldn't find any towers, and was disrupted by other instruments/radios in the aircraft.

            You presume your tiny little experience with your silly little iphone applies in the far north, in third world countries, in the middle of god forsaken Nevada, and the South Pacific.

            Its all about functionality, and knowing the runway alignment when

        • by AK Marc ( 707885 )
          How do you propose that pilots figure out what the "true" cardinal direction is as they approach the airport?

          Every tower has its own frequency. He has a book with him that he'll be looking in to get the frequency (or just ask the last tower he was talking to what to use for the next one, but that's inappropriate). Whatever he does to get the frequency for the tower of where he's going (whether memorization or looking it up) can hold the declination. It isn't hard.

          I guarantee they don't have time to d
    • Happened in Falköping, Sweden to: []

      But it was just a retarded truck driver who had drove them over.

      People started to talk about fish, bees and some idiots about electromagnetic waves from phone antennas, UFOs, (US) government supposedly spraying barium, strontium and so on into the atmosphere showing pictures of planes with regular trails and saying "OMG OMG OMG!" ... Oh well. And the bees (actually) died from some Mon

  • by Bones3D_mac ( 324952 ) on Thursday January 06, 2011 @03:47PM (#34781396)

    if we'll see a similar phenomenon with the bee population as we start moving into the warmer months ahead. Perhaps it's not just a cell phone boom that was to blame last year...

    • Are you pondering what I'm pondering? Perhaps the cell phone boom is causing the magnetic pole shift!
  • Not rare at all (Score:5, Informative)

    by Urban Garlic ( 447282 ) on Thursday January 06, 2011 @03:48PM (#34781400)

    Changing magnetic deviation due to movement of the magnetic pole goes on all the time. Runways are numbered according to their magnetic heading, plus or minus five degrees, and they have to keep them up to date, is all.

    Two seconds of googling found this comment thread [] discussing a different runway-renumbering from July of 2009.

    Obviously not enough airplane geeks around here...

    • by JDeane ( 1402533 )

      Honestly the comments are more interesting then the article and infinity more informative as is the case with yours.

      If I had mod points I would have given you a +1 informative.

      To be honest until reading your comment I had never really given much thought about the runway numbering scheme.

    • by TheCRAIGGERS ( 909877 ) on Thursday January 06, 2011 @03:58PM (#34781566)

      How am I supposed to panic uncontrollably when level-headed people like you are around?

      Seriously speaking, thank you (and people like you) for being around.

    • Why are we still using compass ?
      With GPS and INS [], the runways could be numbered in relation to ITRF []. Of course, continent drift means some renumbering will be needed, but that would be much less frequently.

      • by kaleth ( 66639 ) on Thursday January 06, 2011 @04:27PM (#34781988)

        Because not every plane has a GPS or INS. (Certified) GPS equipment is still new and expensive for airplanes. INS is very large and heavy, and only used on large commercial jets.

        And perhaps most importantly, a compass always works. If everything else fails, you still have that as a backup.

        • by trollertron3000 ( 1940942 ) on Thursday January 06, 2011 @05:56PM (#34783436)

          Yup. The compass is one of the few instruments required in every aircraft in the US. Give me a tachometer, a compass, and an altimeter and I can navigate an airplane across the US.

          GPS just recently came into the cockpit and the devices are expensive. People should realize that these are aviation instruments, so they need to be certified and are in turn expensive.

          INS isn't in every aircraft simply because not every aircraft needs to be instrument-rated. Some people, like myself currently, only fly in VFR conditions. Removing these expensive instruments saves money, as you said.

          Want to see a pilot bitch? Tell him he needs to buy something. For a great example of this search Google for the term "ADB-S requirement" and see the pilots moan about this new requirement. I should know, I'm one of them :D

      • by Martin Blank ( 154261 ) on Thursday January 06, 2011 @04:43PM (#34782280) Homepage Journal

        The compass requires no electrical power.

        I fly a Cessna 172S equipped with a Garmin G1000. It's a glass cockpit that makes life much, much easier, but I still have a few analog instruments: compass, attitude indicator, airspeed indicator, and altimeter. All of them function on principles in place on aircraft for many decades now, and provide a layer of reliability in case just about everything goes wrong. I can lose the entire electrical system and still be able to fly to the best landing site available, because the compass is based on the Earth's magnetic field, the attitude indicator is based on a vacuum-driven gyro (the vacuum pump is mechanical and run by the engine), the altimeter is based on the static air pressure, and the airspeed indicator is based on both the pitot tube and the static air pressure. (The engine spark is provided by magnetos that will keep providing spark as long as the engine is turning - no battery required.)

        There are complications when flying at night, but that's why I carry a hand-held navcom radio and a couple of flashlights with me in my flight bag.

        • by alexhs ( 877055 )

          Thanks for the answer.

          Happens that I overlook the noncommercial flight angle.
          With fly by wire aircrafts, no electricity means much bigger issues than no compass...
          However it is sound to not have a mixed system with geographical north reference for airports and magnetic north reference for smaller aerodromes.

          kaleth maks the point that INS are large and heavy. Is that true anymore ? Smartphones have gyroscopes and accelerometers now. Don't they have enough precision for flight use ?

          • Flight is not generally as precise as many people think. Extreme precision is required on take-off and landing, and is not as critical in most other phases. In fact, intrument error traditionally provided a certain margin of safety in flight. Charts have for years now contained a warning regarding waypoints:

            CAUTION: GPS accuracy necessitates extra vigilance for other aircraft when navigating near any fix retrieved from a GPS database.

            Basically, the planes fly so precisely using GPS coordinates, and espec

      • by spaceyhackerlady ( 462530 ) on Thursday January 06, 2011 @05:03PM (#34782640)

        Because they offer the best bang for the buck. Because pilots are trained to use them. Because they work. Because aviation is totally anal about "if it ain't broke, don't fix it". This is A Good Thing.

        I'm learning to fly in Piper Cherokees, and I have a magnetic compass and gyroscopic heading indicator at my disposal. Both are accurate, but both have idiosyncrasies.

        The magnetic compass is subject to errors when accelerating or decelerating on east/west courses. It also misbehaves when turning to/from north or south. The heading indicator slowly drifts as Earth rotates underneath it. On long flights you have to periodically re-set the heading indicator.

        The pre-takeoff checklist includes setting the heading indicator to the magnetic compass, and verifying that both read correctly when you pull on to the runway. In the future Runway 01 (13 degrees) will become Runway 36 or Runway 02.


    • Re:Not rare at all (Score:4, Informative)

      by digitig ( 1056110 ) on Thursday January 06, 2011 @05:29PM (#34783012)

      Runways are numbered according to their magnetic heading, plus or minus five degrees

      Plus an alphabetic suffix such as "L" or "R" in the case of parallel runways.

    • Re:Not rare at all (Score:5, Interesting)

      by trollertron3000 ( 1940942 ) on Thursday January 06, 2011 @05:31PM (#34783074)

      I'm a private pilot here in Tampa and I can actually see the runways from my parking garage here south of TIA (actually KTPA). They teach you this during your private pilot's course so it's known to all pilots that deviations occur and poles shift. Magnetic deviation is accounted for in your training and you use other tools to compensate.

      In fact when I fly along I'll use a chart of known magnetic deviations in the area I am flying to find true north. I also have two instruments I can use - a heading indicator and an actual magnetic compass. We set the heading indicator, a gyroscopic-based instrument, using the compass while flying straight or on the ground. This will need to be adjusted as we fly along typically, it "creeps". We use the heading indicator over a magnetic compass because trying to fly accurately with a compass is like trying to balance a unicycle. it's not easy and you chase the dial. We also use GPS but the ultimate navigation instrument for a VFR pilot like myself is a set of eyeballs, we use dead reckoning using navigation landmarks noted on charts or known to us.

      The pilots flying into KTPA will most likely be commercial pilots flying an instrument landing approach. This will not effect them much at all but the runway needed to be shut down so it could be repainted and fit into the FAA regulations. It's as simple as that.

      Not sure why I added all that. Probably because no one else did.

  • by Xocet_00 ( 635069 ) on Thursday January 06, 2011 @03:49PM (#34781426)
    The movements of magnetic north have, on many prior occasions, caused airports to have to redesignate their runways. Since it requires updating of all the charts that aircraft are required to carry (not to mention signage on the ground), it's often deferred as long as possible. Tampa doing this isn't really that significant, although I admit that it's kind of neat in a visual-manifestation-of-invisible-phenomenon kind of way.

    Wikipedia subsection on the subject. []
    • by JBMcB ( 73720 )

      > Since it requires updating of all the charts that aircraft are required to carry (not to mention signage on the ground), it's often deferred as long as possible.

      The signage on the ground and numbering/labeling on the computer equipment is probably a pain, but if I remember my aviation science class correctly, aeronautical charts are updated yearly and commercial aircraft are required to carry the latest, so that's not really a factor.

      • by Orion2 ( 200288 ) <reto AT paulifamily DOT ch> on Thursday January 06, 2011 @04:20PM (#34781912)

        Changes to stuff like this are introduced on a cycle once every 28 days - called an "AIRAC cycle". The AIRAC is synchronized all over the world, so all the systems, charts and the like on the ground and in aircraft can be updated accordingly. Obviously there is some lead time ahead to allow for publication, distribution and update of the information and depending systems.

        Imagine if it was only once a year - every change affecting more than one airspace user or aviation service provider in the world would have to be introduced together. This would in consequence mean that you could only open a new runway, introduce a departure procedure or many more things on that date.

        On top of this there's a notification scheme for distributing info like non-functioning equipment, temporarily closed runways (for which you don't change maps forth and back), procedures to adhere, info about an airshow and the like. This is called a NOTAM - short for NOtice To AirMen.

      • Charts are generally updated more frequently than that, though not as frequently as the AIRAC information that Orion2 mentions. Usually, sectional and terminal area charts are updated every six months or so. As an example, the current LA sectional and TAC are good from 16 Dec 2010 to 30 Jun 2011, and are based on information current as of 18 Nov 2010 for airspace and 21 Oct 2010 for everything else.

      • Charts are generally updated more frequently than that, though not as frequently as the AIRAC information that Orion2 mentions. Usually, sectional and terminal area charts are updated every six months or so. As an example, the current LA sectional and TAC are good from 16 Dec 2010 to 30 Jun 2011, and are based on information current as of 18 Nov 2010 for airspace and 21 Oct 2010 for everything else. All pilots are required to carry current charts with them when acting as a crew member no matter what thei

    • by $RANDOMLUSER ( 804576 ) on Thursday January 06, 2011 @04:05PM (#34781664)
      Here's [] a really cool animated gif from Wikipedia, showing the magnetic declination [] changing over time.
    • by fuzzyfuzzyfungus ( 1223518 ) on Thursday January 06, 2011 @04:12PM (#34781794) Journal
      You do have to pity the chaps responsible for repainting the runways of aircraft carriers whenever their orientation relative to the earth's magnetic field changes...
  • by ASimPerson ( 138798 ) <asim@[ ] ['asi' in gap]> on Thursday January 06, 2011 @03:52PM (#34781464) Journal
    This has happened before, and it'll happen again.

    Airport runway numbers are based off their magnetic headings with the last zero removed. So a runway that runs due south/north is 18/36 (i.e., it faces 180 degrees south and 360 degrees north - 0 isn't used). A runway that runs due east/west is 9/27. And so on. When there are parallel runways facing the same direction, the L, C, and R designations are used. A pair for parallel east/west runways are 9R/27L and 9L/27R.

    So as the pole drifts this sometimes causes runways to have be renumbered. One previous example is Reagan-National airport [] in Washington, D.C., where runways 1/19 and 4/22 were originally 18/36 and 3/21.
  • by Elder Entropist ( 788485 ) on Thursday January 06, 2011 @03:52PM (#34781466)
    Your "rapid magnetic pole shift" link is to an article about the (fairly ridiculous) rapid shift of the axis of rotation of the planet rather than the magnetic pole. The two really should not be confused.
    • by rjhubs ( 929158 )
      Yeah I'm not sure why Timothy felt the need to tack that on the end. The magnetic poles and rotational poles are separate entities. Conflating the two is usually just done by 2012 doomsday people who want to show the moving magnetic poles as a possible indicator of the apocalypse in our future
  • Its a change in magnetic variation (deviation is the discrepency in a magnetic compass due to its electromagnitic surroundings). Happens all the time. It's only when the change exceeds certain tollerances that they change the runway numbers. And those tollerances all depend on when that particular airport was last numbered.
  • no, i don't like getting irradiated by the cosmic radiation, thank you very much

    we'll all be living in cement bunkers with no windows, eating mutant irradiated food farmed by farmers in radiation suits

    and in geological time, a rapid N-S reorientation will still take what, decades?

    and such a shift is still decades away, even if it starts accelerating dramatically, i think... gulp

    • by BobMcD ( 601576 )

      and in geological time, a rapid N-S reorientation will still take what, decades?

      Don't know what 'geological time' means, exactly, but in human time they seem to be estimating 3000-5000 years for a excursion and twice that if it actually involves the core as well.

    • utter rubbish, homo erectus lived through a few reversals just fine. There is no evidence whatsoever of reversal causing any kind of extinction, nor is the geomagnetic field the only thing that shields Earth from cosmic radiation. The solar wind interacts with the ionosphere to provide additional shielding, and that isn't going away.

      • oh yeah, there's just that massive increase in cancer rates

        what's the problem with a huge dent in our mortality, a big jump down in our life expectancy?

        nothing to worry about with a massive increase in ambient radiation, nah...

        • Not a valid concern, palaeopathology has confirmed that cancer was exceedingly rare in primates until the start of the industrial revolution. Progress gives you cancer, not cosmic rays.

          • palaeopathology has confirmed that cancer was exceedingly rare in primates until the start of the industrial revolution.

            Cancer tends to be an old person's disease. Not saying that the industrial revolution didn't introduce lots of new causes for cancer, but before then, primates who lived long enough to be chronologically old were pretty rare.

          • Progress mostly only "gives you cancer" because it prevents you from dying from everything else first.
          • []

            *most tumors are in soft tissue which doesn't preserve well

            *people didn't live long enough for most cancers to be very prevalent.

            "For both groups, the authors wrote, malignant tumors “were not significantly fewer than expected” when compared with early-20th-century England. They concluded that “the current rise in tumor frequencies in present populations is much more related to the higher life expectancy than primary envi

      • Species can live through increased deaths and cancers, but it doesn't mean the individuals will be happy doing so.
      • by qwijibo ( 101731 )

        It's entirely possible that a dramatic magnetic shift could cause disruption to electronic services, and I'm sure that if Facebook were down for days, there are millions of people who would just die.

  • Birds (Score:5, Funny)

    by rewt66 ( 738525 ) on Thursday January 06, 2011 @04:04PM (#34781658)

    The birds got confused by the discrepancy between runway numbers and magnetic north, couldn't figure out where to land, ran out of fuel, and crashed?

    • No, they were dizzy from smelling the paint fumes from repainting the designators in their nests.

  • Sure, runways are numbered according to their compass heading, but the omission of the last digit tells me that it doesn't need to be all that accurate. That makes it unlikely that this number is used in navigation.

    I'm no pilot, but the only actual function of the runway number I can think of is the visual identification (to make sure the pilot is lining up on the correct runway). What would go wrong if Tampa just kept using the number 18R/36L?

    • The pilot of the Prussian Embassy's postal Autogyro would get confused.

    • by Umuri ( 897961 )

      Now imagine if they can't see the runway.
      If they're told to land on runway 24, and they're going by instruments oriented 24, and suddenly the runway is 25, they'll be shooting off it after too long.
      Likewise, if they're told to land on runway 25, but they see 24 painted on the ground, they might be confused.

      Basically, i'm betting the change is because they have to go by the RIGHT designation due to instrument assisted landings where visibility is poor, and therefore are updating the visual designations so th

      • by blair1q ( 305137 )

        If they can't see the runway, it doesn't matter what is painted on it.

        The lateral error is going to be far more significant than the angular error in any case.

        If they can be told how to find the end of the runway, they can be told how to line up on it regardless of its name.

      • If they can't see the runway, they're going to use ILS (instrument landing system), which is far more precise and is runway-specific. With appropriate equipment, it is technically possible to land in a true zero-visibility condition, and in some cases for the plane to land itself (including flare, touchdown, nose down, braking, and stopping), but regulations have certain minimums for landing specific to each airport and require the pilot to be in manual control below certain altitudes above ground level.

    • Then there is Atlanta that has 4 parallel runways. So they couldn't use the L,R, and M. I think they 'lied' about the heading on two of them.

  • by Sponge Bath ( 413667 ) on Thursday January 06, 2011 @04:14PM (#34781830)
    Build the runways on giant wheeled platforms on rails that can be reoriented to the magnetic field so that you never need alter the runways numbers.
    • by blair1q ( 305137 )

      Or just build them on compass needles and it will take care of itself.

      Or install digital readouts where the painted numbers are.

      Or paint a giant colored spot instead of a number. "Flight 234 cleared to land on Runway Cerulean Left."

      • by sjames ( 1099 )

        Or paint a giant colored spot instead of a number. "Flight 234 cleared to land on Runway Cerulean Left."

        Damnit Jim! I'm a pilot, not an interior decorator!

    • by dcw3 ( 649211 )

      As an engineer...

      ...for Microsoft?

    • by Rary ( 566291 )

      Build the runways on giant wheeled platforms on rails that can be reoriented to the magnetic field so that you never need alter the runways numbers.

      And while you're at it, make one of the runways function like a treadmill, and end that debate once and for all. ;)

  • There is evidence in cooling magma Earth's poles can and have changed rapidly. []
  • When I first started flying most of Florida was on or near the zero isogonic line (meaning that magnetic north = true north). This line r

  • Why do they use magnetic north and not true north?

    That way they wouldn't have to renumber runways periodically and reprint maps and charts leading to confusion when someone has an out of date chart.

    Most small plane pilots fly close enough to home that they just have to remember their deviation from magnetic north.

    Larger private plane and commercial pilots already have electronic equipment that can show them true north.

    They already use true north in areas where compass readings are unreliable by appending T

    • by dcw3 ( 649211 )

      Because when you're sitting in the cockpit, looking at your compass, you don't see true, you see magnetic. You are able to adjust aircraft compasses for the magnetic deviation (shown on nav maps, and flight charts).

  • If "The Core" taught me anything, its that all we have to do is make a subway train to the core of the Earth, blow up some bombs, and we can restart the magnetic spin. How big a deal is magnetic north moving a few degrees? I bet that would only take a couple nukes at most!

  • Every once in a while (geologically speaking) the earth's magnetic poles will reverse! No one knows why. And the magnetic field protects us from solar winds and cosmic radiation, which would otherwise destroy earth. What keeps the field going? The earth's molten core. But it's cooling off slowly and one day the magnetic field will be gone and all life on earth will probably end. I propose the next environmental movement be to SAVE THE MAGNETIC FIELDS! ;)

    "Based upon the study of lava flows of basalt th

  • by element-o.p. ( 939033 ) on Thursday January 06, 2011 @05:40PM (#34783212) Homepage
    I learned to fly at Elmendorf AFB, in Anchorage, Alaska back in the early '90s. When I first started flying at the Elmendorf Aero Club, the main runway was runway 05. A few years later, it was redesignated runway 06. Merrill Field, a civilian airport just a couple of miles away, also had to change the primary designation from 06 to 07 at about the same time.

    The magnetic poles shift with time, eventually by a significant factor. Since runways are designated by magnetic heading (for example, Elmendorf's runway 06 means the runway is pointed roughly to 60 degrees, and Anchorage International Airport's runway 14 is pointed roughly to 140 degrees), every so often airport management has to redesignate the runways to match the approximate magnetic heading with which the runways are aligned. It's no big deal, and has been happening for as long as there have been runways. All of the speculation at the end of TFS about "...shifting poles finally starting to affect air travel..." and "falling birds" is alarmist nonsense.
  • True North (Score:4, Interesting)

    by dogsbreath ( 730413 ) on Thursday January 06, 2011 @06:40PM (#34784010)

    I'm Canadian you insensitve clod. We use True North (coincidentally Strong and Free) for runway designations and thus are immune to drifting runway numbers. Let's hope desperately that the Earth's spin axis doesn't start moving!

    Strangely... as the years go by, I AM feeling a growing desire to learn the Cyrillic alphabet.

    • Re: (Score:3, Informative)

      by Russ1642 ( 1087959 )
      You only do that way, way up north where compasses aren't reliable. The runways in Canada use magnetic numbers just like everyplace else. At the Edmonton City Centre airport there's a pub located at the end of runway 30. The pub is named Runway 29, but they didn't want to change their name when the magnetic pole moved and the runway was renumbered.

"Let every man teach his son, teach his daughter, that labor is honorable." -- Robert G. Ingersoll