( AERIAL VIEW OF TAMPA AIRPORT. The Runway number being changed is of the long vertical runway at the left of the image)
( The Heading alignment circle) Tampa Airport in USA was closed down till Jan 13 2011 by the authorities to reprint the numeric designations at the end of the runway and change the Taxiway signs DUE TO THE NOTED EFFECTS OF THE SHIFT OF EARTH'S MAGNETIC NORTH POLE AND INCREASE IN MAGNETIC DECLINATION AT TAMPA AIRPORT
1} Rules of numeric representation at the Runway ends.
The orientation numbers at the end of the runway are written in numeric value between (01 - 36) which is 1/10th of the magnetic azimuth of runways heading allignment with respect to Geographical north pole
That is if 9 is written it means 90 deg from east and meaning runway is East-West oriented.
If 18 is written it means 180 deg and runway is South-North at that point.
If its 27 it means 270 deg meaning runway from West to East and 36 written means 360deg and indicating runway from North-South with that approach line.
But these numeric representations work well only for areas away from the North Magnetic pole where magnetic declination ( Angle between the line of Geographic north pole and the magnetic north pole) is less.
But for Airports lying in the Northern Domestic Airspaces of Canada lie near to the magnetic north and for them the Magnetic declination is very large which affects the numeric representations of runways a lot!
2) Tampa airport closed
Tampa is a gulf coast bay city in USA. The main runway currently named as 18R,36L meaning Runway pointed north at 360 deg heading allignment from south.
But at present Magnetic North Pole is approaching Russia by 64km every year and was at 82.7N,114.4W in 2005.
So considering the large magnetic declination now in Tampa authorities have decided to change the number. The Runway headings are rounded to nearest 10 degrees. So if the magnetic declination is more than this value, runway headings need to be changed.
So, Main runway of Tampa airport will be named as 19R/01L meaning runway pointing slightly away from North towards East between North and NNE.
3) EARTH'S MAGNETIC FIELD-
Earth's magnetic field is there because of an ocean containing iron which is electrically conducting medium which generates the magnetic field around the earth. With the rotation of this solid core and the liquid core around it, the magnetic north also moves away continuously and in west direction.
The working of Earth's magnetic field is similar to a dynamo effect due to Electro-Magnetic induction.
The Earth's Magnetic North pole is moving in the regions of higher latitudes ( Say moving north)
4) IS IT RELATED TO END OF THE WORLD IN 2012??
NO, NO, NO, NO,NOOOOO!
Its rubbish to say that closure of an airport due to movement of Magnetic North pole is adding to the so called End of The world Phenomena in 2012.
Near all prominent airports change their runway numbers after some period. In July 2009, London's Stansted airport in UK changed the RNY number from 05/23 to 04/22
Shifting of Earth;s magnetic poles is a very common and natural phenomena which has happened and is happening since the formation of the magnetic field.
Also, it takes a very long time for a geomagnetic reversal when the magnetic north pole is near Geographic South pole and magnetic south near Geographic north pole.
So nothing will happen in 2012 FOR SURE.
