Only 41 thousand years ago compass needle on our planet would show to the South - how on Mars now. Scientists from Gelmgolts Association of German research centres (more precisely, of its Center of Sciences about the Earth) made this conclusion after studying the samples of bottom sediments of the Black sea.

In addition to extreme changes in temperature in Greenland, any catastrophic consequences neither the climate nor for biodiversity weakening of the magnetic field and the eruption of the volcano for some reason did not.

Then on the planet was the ice age, and cash humanity more fond of survival, rather than the development of any compasses. Therefore, before breaking templates nothing happened.

But, strictly speaking, it is not too late. Researchers led by Norbert Kovacica and Helge the Centre has found that the rate of change of magnetic poles of the Earth was just a record. Inversion of the magnetic field in the history of the planet, of course, happened, but no regularities in the change has not been noticed: that tens of millions of years is nothing, then follow each other every few tens of thousands of years. However, before this discovery was thought that the last time the magnetic poles changed places 780 thousand years ago, and lasted change 1 200-10, 000 years. Note also that the scientists ' opinions on this issue differ, as well as the magnetization of the then sedimentary rocks in different parts of the world.

But, it turns out, 41 thousand years ago it was not so. "Geometry of the field inverted polarity, which pointed in the opposite of the current configuration direction, there were only 440 years and was associated with the magnetic field, which power was the current quarter, " explains Norbert Novacek. - Actually change the polarity lasted for only 250 years. In geological time scales, this very quickly." And indeed, if in 2009 the speed of movement of the North magnetic pole was 64 km/year, per 1 000 years even in constantly changing direction he may move, say, to Antarctica. But for 250 years?!

The most interesting thing is different: according to all calculations, it turns out that for this quarter of a Millennium magnetic field was twenty times weaker than the present. The computer industry was lucky: grow it in that era, it would be destined to stay forever tube, because the level of cosmic radiation that reaches the Earth's surface, scary would complicate the work unshielded transistor circuits.

These dramatic events peak of radioactive beryllium-10 in samples of ice that time has not kept itself waiting. The same of course applies to carbon-14.

In addition, the study of the samples showed that 39 400 years ago, that is close to a changing magnetic field, happened other disasters - say, the eruption of the volcano in Italy, made in the atmosphere to 350 km3 of ashes. Of course, it caused climatic variations, traces of which mark and German scientists. True, they had not too deep impact compared with other factors that influenced the weather in that era.

But there are other issues. Think of the hypothesis stating that during the change of magnetic poles of the Earth's magnetic field is so weak that a sharp increase in radiation should seriously harm to all living and lead to much more significant consequences. So, it was argued that, if you do nowadays, mankind would have experienced a global catastrophe, and perhaps would have been lost.

And finally. As a General place it is often argued that the magnetosphere protects, without which life on Earth could not exist. They say, Mars, the magnetic field which is very little, have lost much of their former oceanic and atmospheric partly due to the direct effects of the solar wind, bearing them in space (the truth, the Moon, mercury and many others were somehow Vice versa).

How to combine all with 250-year twentyfold with the decline in the magnetic field, which did not lead to any mass extinctions of species? Moreover, usually at the magnetic equator intensity of the magnetic field of the planet is twice less, than at the poles, and 1.5 times higher than on average in the hospital". Where are the traces of destruction of species in his neighborhood in conditions tridtsatiletnej weakened field? Because, among other things, lived here dozens of generations of Homo Sapiens - creatures that are considered highly vulnerable to radiation...

A study published in the journal Earth and Planetary Science Letters.

Based on the materials Phys.Org.