Krakatoa, the Indonesian volcano that erupted so violently in 1883, produced many recorded effects that are frequently used as yardsticks when discussing the possible consequences of similar events in the past, particularly the second millennium BC destruction of Thera, a leading contender in the Atlantis stakes. The Krakatoan eruption had a detrimental effect on global climates for some years.
However, this was not the first time that the eruption of Krakatoa had calamitous global consequences. David Keys (image below), an archaeological journalist, details the effects of an eruption of Krakatoa in 534/5 AD, in his book, Catastrophe. This book was the subject of a documentary on the UK’s Channel Four(d). A few years before his book was published Keys wrote an article entitled: Comet may have caused catastrophe on Earth(e), in which he dismissed a volcanic eruption as the cause of the 6th century crop failures, plagues, wars, social unrest and widespread deaths, yet his subsequent book advocates[p.269] a massive eruption of Krakatoa as the culprit. Around the same time, Mike Baillie was about to publish his Exodus to Arthur in which he argued
strongly that the mid-6th century range of catastrophes were caused by a cometary impact. Five years later Baillie co-authored with Patrick McCafferty another book linking comets with Irish mythology, The Celtic Gods, in which they point out that Keys’ proposed huge eruption has not been reflected in any of the various Greenland ice cores in the form of a volcanic-acid spike[0112.164]!
This debate regarding the cause of the global catastrophes in the mid-6th century would appear to be far from over. A 2015 report(f) suggests that a series of North American volcanic eruptions in 536 AD had such a detrimental effect on the climate of Europe that it contributed to the final demise of the Roman Empire. Furthermore, there is now evidence(g) that the eruption of the El Chicon volcano in Southern Mexico around 540 AD led to the disruption of the Maya civilisation. Matthew Toohey from the GEOMAR Helmholtz Centre for Ocean Research in Kiel, Germany, has suggested the possibility of a double event!
Early in the 19thcentury the eruption of Tambora, also in Indonesia, was even more powerful(a). However, the most violent eruption of the last two million years also took place in Indonesia 74,000 years ago, when Mt. Toba erupted with devastating consequences for the Indian sub-continent and further afield(b). The Toba caldera is now Lake Toba. A recent study suggested(c) that the Mt.Toba event led to the near extinction of humans.
The Theran eruption was equivalent to the 19th century Krakatoa event when measured according to a volcanic explosivity index (VEI), based on quantitative criteria, as discussed in Walter Friedrich’s book on Thera.
Today, when we watch the 20th century eruption of Mt. St. Helens or the Montserrat volcanoes on our televisions, it gives no real notion of the incredible power of these events or the absolute terror that was experienced by those living close by.
*(d) http://www.davidkeys.co.uk/davids-documentaries/ (Link broken Nov. 2018)*
Fire in the Sea: The Santorini Volcano: Natural History and the Legend of Atlantis  was written by the German, Walter Friedrich, who is now Professor of Geology at the University of Aarhus in Denmark. The book has now been translated by American Professor of Geology, Alexander McBirney.
The book tells the story of one of the most famous islands in the Aegean, Santorini, and its possible connection with the even more famous Atlantis. Santorini has had many names over the millennia; to the ancient Greeks it was Calliste, later becoming Thera and today is Santorini, from the Italian, Santa Irene.
The island of Thera exploded in the second millennium BC with a degree of ferocity, that fortunately, has not been seen since, with the exception of the 1815 explosion on the Indonesian island of Tambora. It not only devastated the island itself, but probably led to the collapse of the Minoan civilisation centred on nearby Crete. This is disputed by some, who date the Minoan collapse to around one hundred and fifty years before the Theran eruption(s). Its effects were felt across large swathes of the Eastern Mediterranean region leading to crop failures and civil unrest. The eruption has been linked with the Biblical plagues of Egypt, but this is still the subject of debate as is the precise date of the eruption/s.
Friedrich considers the evidence for linking Atlantis with Thera and concludes that the question is still open and may be resolved through the ongoing excavations on the island at Akrotiri and in the Nile Delta.
The focus of the book is on the geology of the island and is written in a very readable style and excellently illustrated. Geologists, historians and the general public will find this a fascinating tome. It is a must for anyone interested in the history of the eastern Mediterranean and Atlantis.