 A second event in AD 993/4 has also been found from 14C in tree rings, but at a lower intensity., and another event was found for 660 BCE This event also produced measurable increases in 10Be and 36Cl in Greenland ice cores.If these events are presumed to be produced by energetic particles from large flares, it is not easy to estimate the particle energy in the flare or compare it with known events.The Carrington event does not appear in the cosmogenic records, and neither did any other large particle event that has been directly observed.