Volcanic eruptions in the Mediterranean before A.D. 630 from written and archaeological sources.

Written and archaeological sources from the Mediterranean region have been exhaustively searched for evidence of historical volcanism before the year AD 630. Volcanic eruptions are identified here by two methods: direct observations, which give information about Mediterranean volcanoes, and indirect, atmospheric observations, which give at least the dates of very large explosive eruptions that occurred somewhere in the N hemisphere. Seven or more very large explosive eruptions have been detected by these methods. It is found that atmospheric veiling and cooling were quite marked for approx 1yr after the eruptions of 44 BC, AD 472, AD 536, and AD 626 (relevant data are lacking from the other eruptions). If the AD 536 eruption was a very distant one (Rabaul, New Britain?), it may have been the most explosive in recorded history. There is independent evidence of the sizes of the eruptions that took place in these years: at least 5 of them coincide with the strongest acidity signals in Greenland ice for this period. In the case of the smaller eruptions, reliable (though necessarily incomplete) chronologies are presented for Etna, Vesuvius, and the other active Mediterranean volcanoes. Full documentation from the original sources is provided throughout.-Authors