After Alexander the Great died in 323 BCE, Ptolemy I – a Macedonian Greek general serving under the notorious monarch – became the ruler of Egypt. His dynasty continued until the famous suicide-by-asp of Cleopatra VII – yes, that one – together with the successful Roman conquest of the area in 30 BCE.
Francis Ludlow, a climate historian who works at Trinity College Dublin, had long suspected that there was more to the story of the fall of the Ptolemaic Kingdom than merely a successful invasion made by the civil war-weary Roman regime. According to a new Nature Communications paper he and his colleagues wrote, a volcanic eruption at the time might have been a determining factor in the fall of the pharaohs.
As Ludlow and his colleagues explain, at the time, the kingdom’s prosperity was directly linked to the flow of the river Nile. That's a river which is fueled primarily by the monsoon rainfall in today's Ethiopia's highlands, and every summer, the flooding of this river allowed the arid area to grow its agriculture to the fullest extent.
Writings at the time of the kingdom’s fall have proven that the Nile wasn’t flooding as it used to.According to the Nilometer – who was the oldest annual hydrological gauge in history – it was actually almost running dry. Therefore crops were failing. That led to widespread societal unrest, which catalyzed the empire's fall. But what could have possibly stopped the flooding in the first place?
Climate data indicates that rainfall is affected by volcanic ash since it can alter air currents, cloud formation, and precipitation locations in possibly troublesome ways. Indeed, according to the study, “after five twentieth-century eruptions, precipitation was suppressed across the Sahel into Ethiopia and in the equatorial regions of Africa that feed the White and Blue Niles.”
The team was curious as to whether that same mechanism applied at the time when the ancient empire met its end. Using ice cores from Greenland and Antarctica, they've previously discovered sulfur compounds showing that several significant eruptions were occurring someplace in the world at that time – even though the volcanoes themselves haven't been identified yet.
A view of Egypt and the Nile River, seen from the east. JSC/NASA
"There is no simple method to get to the source of these past eruptions, and often it is only the combination of many methods from many disciplines to nail it down," said co-author Michael Sigl, an analytical chemist at the PSI in Switzerland.
"Often the only direct evidence of climate-impacting eruptions comes with no name tag."
In any case, by using cutting-edge climate modeling programs, the team discovered that the rain belt above the kingdom would have weakened significantly while the dynasty was dying. That would explain why the Ptolemaic military didn't win several territorial wars at that time: the social crisis at home, driven by a lack of food supplies, required more attention.
The study directly connects volcanism and climate change with the destruction of the empire – and it isn't the first time such a connection has been made. In the past, plenty of mighty empires have been wiped out by the fires of Earth, along with the Minoans of Thera, and even perhaps the Mayans.
At one point, it was considered that humanity was almost rendered extinct by the supervolcanic blast at Toba 75,000 years ago, but this has since been thought to be an overestimation. Either way, it’s obvious that when nature feels like lashing out, there is very little we can do about it but hope for the best.
If these eruptions had not occurred, who knows? Perhaps the Roman conquest would have failed, and the history of humanity would have turned out very differently.
Based on: IFLScience
The Ptolemaic Empire in 200 BCE. Thomas Lessman/Wikimedia Commons; CC BY-SA 3.0
Related:
Very informative post for us.
ReplyDeleteDell Customer Support