After a rather strong dust blow Eyyafyaatlayokudl Icelandic volcano in April 2010 and the pre-Christmas collapse in airports in the U.S., Western Europe, and later in Moscow, due to extreme weather conditions, it's time to ask: what more in the short term may interrupt regular flight? Where to wait for a dirty trick?
I must say, there are grounds for serious concern. And we are not talking about something a little predictable, like winter snow. Far from it. A problem that can affect the regularity of operations, has long been known. It is called — the magnetic declination (or deviation — Engl. Magnetic declination) and has been studied for hundreds of years.
January 7 because of the very inducement had to close the airport in Tampa, Florida, USA. Airport workers in a few days had to deal exclusively with the fact that the rearranged seating shall be in compliance with the new position of the magnetic poles of the earth. And all because of that lately the pole if the chain broke and Rushed to Russia, leaving the cozy Canadian waters, which is found from the time of the Time of Troubles and musketeers of King Louis XIII.
Even Christopher Columbus noticed something strange in the behavior of the magnetic compass. Making throws across the Atlantic, the great navigator was sometimes only one at a parallel, that is, the same latitude. This he could not accurately determine the height of the sun. In this magnetic needle instead show all the time strictly on geographic north consistently deviated a few degrees. Columbus and his followers noticed it and made the assumption that the magnetic pole of the planet, and the geographical (which revolves around the Earth) is not the same.
Not only in the XVIII century, it was known that this decline tends to vary. In 1831, John Ross found the Canadian Archipelago where the magnetic needle floating in a special solution, got absolutely vertical. Ten years later, his nephew, James Ross found the south magnetic pole in Antarctica. Since then, the movement of the magnetic poles was the subject of scrutiny.
Why do it in practice? Whatever we have electronics, it crashes. And the magnetic compass is still served the pilots, sailors and geologists. But the cards lined with grid tied to the geographic pole of the planet (he is also walking, but at a very modest distance). A magnetic needle is looking sideways. Farther north, the more pronounced decline of the true direction, geographic meridian. On the cards are even special icons indicating the magnitude and direction of this variation. And planting signs in airports, derives from the declination in one direction or another.
If not walking up and down the pole, then the problems would not exist. But in recent years has increased the speed of displacement of the poles. Throughout most of the twentieth century, the North magnetic pole shifted a speed of 10-15 kilometers per year, and in the first decade of the XXI century, it gained up to 64 kilometers per year and growing.
This means that maps and signs are quickly becoming obsolete and our aircraft in a somewhat different direction than planned. Indeed, over the past ten years the pole "escaped" by a good 500 kilometers. For some, it quietly: they simply pole gets closer or further away, and the course it does not change. And for some pole run sideways, and it has to be considered.
For example, in Petropavlovsk-Kamchatsky rate of change of magnetic declination: zero degrees, zero minutes (meaning the angular degrees). In Bratsk declination of about one and a half degrees, and its rate of change — just three minutes of arc per year. And in Tampa, Florida, by January 13 changed all the signs, magnetic variation is 5 degrees, and its rate of change — 5 minutes of arc per year.
Since one degree 60 arc minutes, and the last time the signs in Tampa established 12 years ago, it is now the deviation from the axis of the runway was changed to 5×12 = 60 minutes, or 1 degree. Is that a lot? 17 meters to the side at a distance of one kilometer. As far as it is unpleasant — it is better to tell the pilots, but, for example, the plane of Polish President Kaczynski crashed near Smolensk, off course on 40-45 meters and crashed at a distance of two kilometers from the runway. This deviation occurs at a distance with an error of 1 degree 20 minutes. And the rate of change in Smolensk declination angle is 7 minutes per year, which is a necessary dose could coming up over 11-12 years. It is possible that Polish pilots used outdated data in the magnetic declination, and it also played a role in the crash.
Returning to Tampa Florida, it should be noted that this airport — not the leader of the magnetic declination and its rate of change. Here are some figures that anyone can get by entering the coordinates of the city in a special calculator NASA.
For example, Moscow declination 9 degrees and 40 minutes, and changed it at 6 minutes of arc per year. London and Frankfurt am Main have only 1 degree west of decline, but it is changing at a rate of 8 minutes per year. In Murmansk the 14 degrees east of decline, and it is increasing year by about 10 arc minutes. Worst of all things in Reykjavik with 15 degrees of inclination and the change in 16 minutes in a year, and in Anchorage, Alaska — where the declination of 18 degrees and 18 minutes of change in a year. For ten years — 3 degrees from the runway.
There is no doubt that at the airport monitor these parameters. But is not the question. Apparently, the shifting of the poles will only accelerate, and therefore the correction in maps and charts will have to do more often. That is Tampa, like other airports, closed more than once.
Experts have said that the current displacement of poles — not just their traditional walk. Quite possibly, they start to change their position. The point is for the Earth familiar. The only question is speed. It used to be that it will take at least a few hundred years (at the current rate — three hundred years). But recent studies Scott Boag and Jonathan Glenn of the U.S. Geological Survey have found evidence that a change of the polarity of the magnetic field of the Earth can happen very quickly, in about four or five years.
During this period, the first time it will weaken, which would reduce the protection against cosmic radiation. And then, in the second half of the term, to grow until it is restored completely. The fact that the weakening of the magnetic field is diagnosed about a hundred years. During this time the Earth's magnetic field has weakened by more than 10%, and the process continues, and with increasing speed.