To this day, not much is known about Earth’s inner core and its contribution to sustaining life on our planet. That could soon change, however, thanks to an analysis of ancient rock crystals by researchers from the University of Rochester, New York.
Among the different layers that make up our planet, the outer core – about 1,800 miles below us – contains liquid iron that plays a key role in creating The earth‘S magnetic. This field, although not visible, plays an important role in supporting life on Earth by keeping the solar wind or radiation streams from Sun in the Bay.
However, somehow, this protective shield has lost 10% of its current strength 565 million years ago. This magnetic field then regained the strength lost just before the Cambrian explosion of multicellular life on Earth.
To find the cause behind this unprecedented change, the researchers studied magnetism locked inside ancient crystals. They used a CO2 laser and a superconducting quantum interferometer (SQUID) magnetometer to analyze feldspar crystals from the anorthosite rock. These crystals contain minute hands which are considered perfect recorders for magnetic information.
The detectpublished year Nature, revealing two important dates in the history of the Earth’s inner core. The first time was 550 million years ago, when the magnetic field began to rejuvenate after reaching the brink of collapse 15 million years earlier. The second most important date found was 440 million years ago, when the structure of the developing inner core changed.
“Because we more precisely limit the age of the inner core, we were able to uncover the fact that today’s inner core is actually composed of two parts. Plate tectonic movements on the Earth’s surface have influenced the inner core indirectly, and the history of these movements is imprinted within the Earth in the structure of the inner core.” speak Geophysicist John Tarduno, also one of the study’s authors.
The study suggests that the formation of the Earth’s solid inner core is likely the direct cause of the restoration of the Earth’s magnetic field. Researchers believe this saved the Earth from the fate of Marslosing its magnetic field makes it vulnerable to the solar wind.