Volcanoes and Egypt

20 Oct 2017

Gary sent in links to this story. So too did Jovan and William. See for example www.abc.net.au/news/science/2017/10/18/volcanic-eruptions-and-the-fall-o... ... the claim is that distant volcanoes triggered environmental change in ancient Egypt leading to the fall of the Ptolemaic dynasty in 38BC. In other words, they are blaming volcanoes that coincided with civil unrest for such political changes as the end of Cleopatra and the beginnings of Roman controlled Egypt - which has to be taken with a pinch of salt. It is guesswork. However, it does come about after a remarkable piece of research and investigation that involved looking at ice cores and Nile flood levels over a long period. The study as it is published concerns just 300 years - between 305 and 30BC. It is well known that volcanoes eject dust and gases high into the atmosphere and these create short lived spikes in global temperature. Naturally, a cluster of volcanoes would produce a more sustained opaque sky lasting for a longer period. As yet there is little research on the role of heavy meteor showers which are also capable of producing high levels of dust and gases even higher in the atmosphere. What is being implied is that dust veil events affect climate on the Earth by restricting the amount of ultra violet light from the Sun. Egypt is affected by levels of water in the annual Nile flood and this varies on how heavy monsoon rains on the Ethiopian highlands are from year to year and decade to decade. Less warmth from the Sun means less evaporation, we are told - but is it as easy as that. A lower global temperature leads to a shrinkage of the temperate zone and an expansion of the polar zone, which on occasion in the past has been fairly extensive over longer periods of time than captured in this study. On these occasions the monsoon track may actually move (somewhat like the jet stream can move as a result of solar wind inter-action with Earth's ionosphere). In this study there was only one major low growth tree ring event, around 210BC - but evidence of volcanoes on a more regular basis have been espied in ice cores (but sometimes in clusters). During the period under study there were 16 eruptions. The authors also found that there were 12 recorded revolts (civil unrest) coinciding with volcanic eruptions 3 of which occurred in the same year as the dust veil, 5 that occurred within 2 years of an eruption, and 1 that occurred within 3 years. This is a pretty comprehensive pattern and should be taken seriously as it may help politicos to prepare for future episodes of climate glitches caused by volcanoes (and several of these appear to be on the verge of erupting). However, there is one qualification to this as they are talking about the Ptolemaic empire which included Cyrenaica (most of modern northern Libya) and the Levant (Syria-Palestine) and some other small pockets of territory. One could make a similar argument for the date of Irish rebellions over the last few centuries. They also seem to have occurred during climate downturns (such as the mid-17th century). However, whether they actually played a role in the success of Rome taking over the Ptolemaic empire is something altogether different as the Romans had developed a formidable military machine that continued to expand exponentially over several hundred years. See also http://blogs.discovermagazine.com/d-brief/2017/10/17/volcanoes-egypt/

   See also http://popular-archaeology.com/issue/fall-2017/article/study-reshapes-un... ... which tells us much te same thing. We may note there is really nothing new about any of this as it has been known over a long time that low growth tree ring events and volcanic signatures in ice cores coincide with societal changes and with the rise and fall of dynasties in countries such as China and the Americas. What is different is that it has all been plotted in detail by using ice cores and Nile level ups and downs in a fairly comprehensive fashion. The study was published in Nature Communications (October 2017) and you will have to read it to find out what the actual dates were. Interestingly, Mike Baillie in his book, 'A Slice Through Time' (Batsford:1995) has a chapter on volcanoes and tree rings/ ice core acidity layers. Within the period of the study he draws attention to a significant low growth event around 208BC. In that same year the Chinese reported that the stars were invisible (as a result of dust veil event). In Germany the tree ring anomaly has been dated 208-4BC. In 207-4BC there were major famines in China and in 205BC the Romans reported famines and an epidemic. In 204BC the Chinese deposed on dynasty and another dynasty took their place - which came about as the emperor and his kin were blamed for the misfortune. I imagine that the volcano cluster is dated to around 208BC - but did other factors weigh in such as a bout of heavy meteoric activity?