Volcanic fallout helped the rise of Roman Empire, say scientists

A view of the ancient Roman Forum in Rome, Italy. Photo / AP file

The rise of the Roman Empire was due in part to a gigantic volcanic eruption 9650km away in Alaska, an international team of scientists claims.

The eruption of the Okmok volcano in the Aleutian Islands of Alaska more than 2000 years ago caused a severe cold spell in Europe that led to crop failures, food shortages and political and social unrest, they argue.

That hastened the demise of the Roman Republic and the emergence of the Roman Empire, according to the team of researchers from the US and Britain.

By analysing traces of volcanic ash in ice core samples from the Arctic, they found that Okmok volcano erupted in 43BC - a year after the assassination of Julius Caesar.

The eruption, one of the largest of the last 2500 years, would have sent colossal quantities of ash into the sky, leading to alterations to the climate worldwide.

Europe suffered unusually wet conditions and an extreme cold spell. Immediately after the eruption, there were ancient Roman accounts of "crop failures, famine, disease and unrest in the Mediterranean - suggesting significant vulnerability to hydroclimatic shocks," the scientists said.

Suggestion that a volcanic event in Alaska in 43 B.C. led to years of cold weather and events that caused the downfall of both Roman Republic and Ptolemaic Egypt. https://t.co/MkAVgD2NPv

— Wrath Of Gnon (@wrathofgnon) June 23, 2020

They pointed out that "historians have previously speculated that a large volcanic eruption of unknown origin was the most likely cause."

Their findings did come with a caveat.

"While it is difficult to establish direct causal linkages to thinly documented historical events, the wet and very cold conditions from this massive eruption on the opposite side of Earth probably resulted in crop failures, famine and disease," they wrote in the Proceedings of the National Academy of Sciences.

Those changes would have "exacerbated social unrest and contributed to political realignments throughout the Mediterranean region at this critical juncture of Western civilisation."

The eruption also coincided with the fall of the Ptolemaic Kingdom in Egypt, heralding the end of the pharaohs.

"To find evidence that a volcano on the other side of the Earth erupted and effectively contributed to the demise of the Roman (Republic) and the Egyptians and the rise of the Roman Empire is fascinating," said lead author Joe McConnell, of the Desert Research Institute in Reno, Nevada.

The two years following the eruption were some of the coldest in the Northern Hemisphere for 2500 years while autumn rainfall in southern Europe was up to four times heavier than normal.