Free Republic

Contemporary chroniclers wrote about a "mystery cloud" which dimmed the light of the sun above the Mediterranean in the years 536 and 537 CE. Tree rings testify poor growing conditions over the whole Northern Hemisphere - the years from 536 CE onward seem to have been overshadowed by an unusual natural phenomenon. Social crises including the first European plague pandemic beginning in 541, are associated with this phenomenon. Only recently have researchers found conclusive proof of a volcanic origin of the 536 solar dimming, based on traces of volcanic sulfur from two major eruptions newly dated to 536 CE and...

Double impact may have caused tsunami, global cooling Pieces of a giant asteroid or comet that broke apart over Earth may have crashed off Australia about 1,500 years ago, says a scientist who has found evidence of the possible impact craters. Satellite measurements of the Gulf of Carpentaria (see map) revealed tiny changes in sea level that are signs of impact craters on the seabed below, according to new research by marine geophysicist Dallas Abbott. Based on the satellite data, one crater should be about 11 miles (18 kilometers) wide, while the other should be 7.4 miles (12 kilometers) wide....