Earthquakes undermine GPS


Every major earthquake shifts the continents on the Earth's surface. Errors that occur because of the testimony of GPS, can lead to problems on a cosmic scale, scientists have found.

The earthquake what happened in the Sea of Okhotsk on May 24,
the echoes of which were recorded in Moscow, led once again to draw attention to the problem of prediction and evaluation of effects of these natural disasters. Effects associated with the release of energy tectonic plates affect not only the residents of seismically dangerous areas of the Earth, but also where the jitter of the planet will know, as a rule, from the news.

The same idea is presented in a recently published in the journal Journal of Geophysical Research the work of the Australian geophysicist Paul Tregoninga of the Australian National University in Canberra.

In their study, seismologists have come to the conclusion that every major earthquake shifts the continents relative to each other on the background of the overall drift.

Since the beginning of the third millennium, the world's recorded 17 major earthquakes (magnitude greater than 8). Using existing models of plate movements and the testimony of more than a stationary sensor global satellite system GPS, the researchers analyzed the effects of distant 15 powerful earthquake recorded since 2000.

The list includes such a devastating earthquake, as the 2001 earthquake in Peru (8.5 points), 2004 Sumatra (9.2 points), and in 2011 in Japan. Each is an earthquake causes a horizontal progress in thousands of miles from his hearth.

A Sumatran earthquake in 2004 forced the move almost half the area of the earth's crust more than 1 millimeter.

In this case, the most stable and fixed on the planet were Australian plate, Western Europe and the eastern part of Canada. On average, the value of such movements is 0.4 millimeters per year. "It is incredible that we were able to notice and fix it! We found a way to deal with these shifts. The scientific community must take into account all these changes, carefully evaluate them and come to an agreement on how to take them into account, "- says the author of the work.

Such minor shifts of continents, of course, will not be a problem for the owners of mobile phones, automobile navigation and tourism, taking signals GPS.

However, these must be taken into account millimeters of scientists engaged in the calculations of the level of the oceans or the orbits of artificial satellites.

"If the coordinates of the monitoring stations are not correct, you can not accurately calculate the orbit," — says Paul Tregoning.

"I think he raised an important issue," — said Don Argus, a specialist from NASA's Jet Propulsion Laboratory for the use of GPS in calculating the orbits of satellites. "Because of these seismic shifts we find it difficult to choose a stable frame of reference. Earthquakes are a lot of complicating the lives of people in our lab, "- he said.

According to Tregoninga, following clarification of the International System of coordinates (International Terrestrial Reference System), which is conducted on the basis of GPS, will have to take into account the effects of major earthquakes. "We have to decide how to improve our system of reference. The scientists involved in regional studies can get different from our results, so we have to give a more accurate answer ", — said Tregoning.

Paul Kotlyar

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