The type of solar emission discovered in the Greenland ice is a particularly powerful type of solar storm called a solar proton event (SPE), which hit some 2,679 years ago. "Our event was about 10 times stronger than any high-energy event observed during the past 70 years", Muscheler told Newsweek.
New research indicates that solar storms can be even more powerful than measurements have shown so far via direct observations.
"These enormous events are a recurring feature of the sun - we now have three big events during the past 3,000 years".
The discovery is alarming, Muscheler explained, as if a storm of a similar magnitude were to hit the Earth today, modern technology could be greatly disrupted. Two examples of dire solar storms in recent times that engendered substantial power cuts occurred in Quebec, Canada (1989) and Malmö, Sweden (2003).
"That's why we must increase society's protection again solar storms".
The evidence they dug up is in the form of radioactive particles previously hidden under the ice sheets of Greenland, and experts are saying the ancient event could be one of the biggest solar storms to have ever hit Earth. SPEs can degrade the Earth's ozone layer temporarily, which can allow hazardous levels of ultraviolet radiation to reach the ground. The sudden rush of particles can pose a radiation risk to astronauts and airline passengers, and can damage satellites, power grids and other electrical devices.
Today that extra radiation would be potentially unsafe for astronauts on the ISS and passengers flying on planes at high altitude, besides threatening a lot of the modern technology we've come to rely on. But according to a study published yesterday in the journal PNAS, scientists have now uncovered these radioactive remnants of the tempest in ice cores from Greenland.
They found traces of chlorine and beryllium isotopes in the ice from the deadly storm over 2,500 years ago.
Scientists have analyzed proton storms for less than a century. The upshot is that these heavy storms are occurring more regularly than we thought they were, and can be more powerful than anything we've seen in the modern era, and that affects contingency planning.
"We need to search systematically for these events in the environmental archives to get a good idea about the statistics - that is, the risks - for such events and also smaller events".
To learn more about SPEs, Lund University's Professor Raimund Muscheler and his colleagues from Sweden, France, Switzerland, Korea, the UAE, and the U.S. analyzed ice cores from Greenland.