Dec. 26, 2018 – Mary Greeley News – Europe’s largest active volcano, Mount Etna, looms large over the island of Sicily but new research indicates that it may pose a threat to the entire coastal population of the Mediterranean.
While many might fear the prospect of a fiery, ash-covered death, akin to the historic tragedies caused by eruptions at Mount Vesuvius, where heads exploded, and blood boiled, a tsunami may prove to be the biggest danger wrought by Etna.
A volcano avalanche in Sicily 8,000 years ago triggered a devastating tsunami taller than a 10-story building that spread across the entire Mediterranean Sea, slamming into the shores of three continents in only a few hours [image].
A new computer simulation of the ancient event reveals for the first time the enormity of the catastrophe and its far-reaching effects .
The Mt. Etna avalanche sent 6 cubic miles of rock and sediment tumbling into the water—enough material to cover the entire island of Manhattan in a layer of debris thicker than the Empire State Building is tall.
The entire slope is in motion due to gravity,”explains geophysicist Heidrun Kopp from the Geomar Helmholtz Centre for Ocean Research in Germany, who recently published research results in the journal Science Advances.
The mountain of rubble crashed into the water at more than 200 mph. It pummeled the sea bed, transformed thick layers of soft marine sediment into jelly and triggered an underwater mudslide that flowed for hundreds of miles.
“It is therefore quite possible that it could collapse catastrophically, which could trigger a tsunami in the entire Mediterranean.”
In April 2016, Kopp’s team strategically positioned five underwater transponders to measure seafloor displacement along the southern edge of Mount Etna. Nothing happened for 12 months but then, in May 2017, the flank moved by 4 centimeters in just eight days.
After careful analysis, the team determined that the slow slip and slide is evidence that gravity, not seismic activity, is to blame for the mountain’s gradual collapse into the Mediterranean.
Analysis of the seafloor indicates that the sliding movements, which average 14 millimeters or 0.55 inches per year, actually impact a far greater land mass than previously believed, increasing the risk of a “catastrophic collapse” leading to an eventual tsunami, as opposed to a confined eruption on the island of Sicily alone.
“We have been monitoring Etna on shore for around 30 years now, but 30 years is nothing compared to the age of Etna, which is 500,000 years old,” Dr Morelia Urlaub from Geomar Helmholtz Centre for Ocean Research told The Independent.
“It could happen in 10 or 100 or 100,000 years – we can’t tell.”
Their recreation suggests the tsunami’s waves reached heights of up to 130 feet and maximum speeds of up to 450 mph, making it more powerful than the Indonesian tsunami that killed more than 180,000 people in 2004.
Some three and a half hours later, computer models suggest, huge waves had traversed the entire Mediterranean crashing on the eastern coast of today’s Israel, Lebanon and Syria.
The researchers have also linked the ancient tsunami with the mysterious abandonment of Atlit-Yam, a Neolithic village located along the coast of present-day Israel. When archeologists discovered the village about 20 years ago, they found evidence of a sudden evacuation, including a pile of fish that had been gutted and sorted but then left to rot.
“A tsunami was not suspected before,” lead researcher Maria Pareschi told LiveScience.
According to Pareschi, if the same tsunami struck today, Southern Italy would be inundated within the first 15 minutes.
In one hour, the waves would reach Greece’s western coasts. After an hour and a half, the city of Benghazi in Northern Africa would be hit. At the three-and-a-half-hour mark, the waves would have traversed the entire Mediterranean to reach the coasts of Israel, Lebanon and Syria.
Avalanches and minor eruptions still occur on Mt. Etna today, but so far, nothing approaching the magnitude of the ancient event.
“Should the Neolithic Etna tsunami have occurred today, the impact is tremendous because the Eastern Mediterranean coasts are very inhabited ones,” Pereschi said.