Where is the earth’s magnetic field going?

Where is the earth’s magnetic field going?

The Earth’s magnetic field protects against cosmic rays, gives orientation to migratory birds and shows the direction. But the magnetic field wanders – faster than expected. Current calculations are impossible due to the US shutdown. Geophysicists expect in completely different periods: A few weeks are geologically not even the blink of an eye. Actually, the “World Magnetic

The Earth’s magnetic field protects against cosmic rays, gives orientation to migratory birds and shows the direction. But the magnetic field wanders – faster than expected. Current calculations are impossible due to the US shutdown.

Geophysicists expect in completely different periods: A few weeks are geologically not even the blink of an eye. Actually, the “World Magnetic Model” should finally be updated on January 15, 2019, but with the “Government Shutdown” in the US , the publication of the calculation model will take a few more weeks. The researchers will have to be patient.

The World Magnetic Model (WMM) is actually published by the US National Geophysical Data Center (NGDC) and the British Geological Survey (BGS) and updated every five years. But the NGDC website is unavailable. It has been shut down due to “lack of funds,” they say. The current model version was created in 2015 and should actually apply until 2020. But the current model is not right at the front and back because the magnetic pole is moving faster and faster.

At the beginning of the century he was near the Northeast Passage in Canada. Now it is located much further north almost near the geographic North Pole. He wanders surprisingly fast towards Siberia, annually by about 30-50 kilometers. That is about three times as fast as it was 100 years ago. Last year, he crossed the international border into the eastern hemisphere.

More important than the position of the magnetic North Pole, however, is that the Earth’s magnetic field has become ten percent weaker since records began 175 years ago – again, the reasons are unclear. For life on earth, however, it is less important where the respective magnetic poles are, but how strong they are.

A weak geomagnetic field not only makes it difficult for migratory birds to orient themselves. Above all, a strong geomagnetic field also protects the earth from aggressive cosmic rays and solar winds. A weak magnetic field reduces the protective ozone layer and the dangerous UV rays penetrate more easily, especially in the polar regions.

The geostationary satellites are also less protected in a weak geomagnetic field. Radiation or particles from space could significantly affect them and severely restrict communication.

The geophysicists debated in the past year excitedly even about a possible pole reversal, on average, a pole shift occurs every 200,000 to 300,000 years. However, the last pole shift took place 780,000 years ago. As I said, geophysicists expect in completely different time periods.

A Chinese study caused a sensation last year, according to which the last pole reversal at the beginning of the last ice age took place relatively quickly – in just 144 years. So far, the researchers had assumed that a page change takes several hundred years.

The Chinese researchers had studied stalagmites in limestone caves and were able to detect the fluctuations of the magnetic field. However, about 98,000 years ago, no pole shift took place, but probably only a so-called “excursion”, a temporary weakening of the magnetic field, before the magnetic field collapsed completely.

For a more accurate calculation, however, the most correct World Magnetic Model (WMM) is urgently needed. However, the geomagnetic model is not only used by scientists, but above all by the numerous national and international service providers who give orientation to shipping traffic, for example. Nautical charts, navigation systems and smartphones with magnetic field sensors, ie virtually all devices with Android or iOS operating systems, depend on a correct model.

The model provides worldwide the declination (also: Ortsmissweisung), ie the angle between the direction to the magnetic and geographic North Pole. This angle changes the more you go north and must be taken into account especially when navigating with the compass. In addition, the WMM also describes the Earth’s magnetic field for a range of one kilometer below the Earth’s surface up to an altitude of 850 kilometers.

The Earth’s magnetic field is created deep down in the Earth’s interior, where huge streams of molten iron move at the boundary between the Earth’s core and the Earth’s mantle. These currents create the magnetic field. When these currents change or slow down, perhaps due to a tectonic shift in the Earth’s plate, the Earth’s magnetic field also changes.

More clarity about the position and intensity of the earth’s magnetic field will probably only occur when the political conflict parties in the US settle their earthly conflicts and the now rather inaccurate World Magnetic Model is brought back to its current state after the shutdown.


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