Eruption of Alaska’s Okmok Volcano Contributed to the Rise of the Roman Empire, but How?

Rome became an empire after 450 years as a republic upon the assassination of Julius Caesar in 44 BCE. The long and triumphant reign of its first emperor, Augustus, started a golden age of peace and prosperity in the country.

However, history records suggest that the period of nearly two-decade power struggle was marked with strange sightings in the sky, unusually cold weather and widespread famine. A new study reveals that this might be caused by the extreme volcanic eruption in Alaska.

The research was published on Monday in the Proceedings of the National Academy of Sciences.

Eruption of Alsaka's Okmok Volcano

According to a report from Science Alert, an international team of scientists and historians found a link between the unexplained extreme climates in the Mediterranean with the crater-forming eruption of Alaska's Okmok volcano in 43 BCE.

They used an analysis of volcanic ash or tephra found in Arctic ice to explain the connection between the two events.

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

The team was able to gather evidence from across the world, including those from tree-ring based climate records in Scandinavia to the cave formations in northeast China.

They fed the information they collected to the climate models and found that the two years following the eruption were the time the Northern Hemisphere was in its coldest in 2,500 years.

Climate models suggest that the temperatures during that time may have been seven degrees Celsius (13 degrees Fahrenheit) below average for the summer and autumn following the eruption. Moreover, autumn's rainfall reaches as high as 400% of normal in Southern Europe.

According to classical archaeologist Andrew Wilson of the University of Oxford, these wet and extremely cold conditions in the Mediterranean during the agriculturally important spring through autumn seasons probably reduced crop yields and caused problems in supply during the ongoing political upheavals of the period.

It also coincided with the time when the Nile failed to flood the plains, and the disease and famine emerged, said Joe Manning of Yale University.

The rise of the Roman Empire

But the rise of the Roman Empire did not only brought an end to the Roman Republic. It has also ended the dynasty of Ptolemies, the last of the pharaohs.

McConnell and Swiss researcher Michael Sigl began an investigation on what they found as an unusually active layer of ash in an ice core sample in 2019.

They then made new measurements on the ice cores discovered in Greenland and Russia, some of which were drilled in the 1990s and stored in archives. The scientists were able to make out two distinctive eruptions.

These are the powerful but localized and short-lived events in early 45 BCE, followed by a more significant and more widespread event in 43 BCE, with a fallout lasting for more than two years.

Furthermore, the eruption also explained the unusual atmospheric phenomena noted on the historical records, such as solar halos, the sun darkening in the sky, or three suns appearing-a phenomenon known as a sun dog.

But authors noted that many of these observations happened long before the Alaskan eruption took place, and could be related to the smaller eruption in Mount Etna.

McConnell emphasized that many factors should be considered in the fall of the Roman Republic and the Ptolemaic Kingdom, but the eruption of the Okmok plays an important role and helps fill a gap that puzzled the historians on the rise of the Roman Empire.