July 12, 2013. The latest research suggests that the earth rotates at different speeds at certain times of the 5.9-year cycle. Scientists have also found a link between changes in the Earth's rotation and the sudden changes in the magnetic field of our planet. The speed of rotation of the globe can change quickly, a millisecond per day, because of the wind or liquid on the surface of the Earth. Scientists can measure how fast the Earth spins, watching the distant objects in space and time and counting how long it takes to get back into the field of view — that is, one day.
July 11 in the journal «Nature» published a study that describes the tendency of changes in the length of day, less weather conditions that allowed the researchers to blame the liquid core of the Earth.
Previously, researchers have noted signs that hint at a six-year variations in day length, occurring at about the same time. A new analysis showed that surprisingly regular cycle, and the maximum change in the length of the day is every 5.9 years. Using long-term data archive, the researchers also noted that fluctuations occurred just in time for half a century. "It can talk about something important," — says the opening geophysicist Bruce Buffett of the University of California, who was not involved in the research. — But it is too early to talk about what causes fluctuations. "
Such persistence undermines one of the hypotheses to explain the cycles — fluctuations of solar energy, which are more volatile, said study author Richard Hill of the University of Liverpool. Contrary to this, the cycle triggers something inside the earth. Hill's team also reported sudden and tiny increase or decrease the speed of rotation of the Earth, which coincided with the sudden changes in the behavior of Earth's magnetic field, known as the geomagnetic "jerks." New data on the duration of the day may help scientists understand what causes the mysterious tug adds Buffett.