The second largest volcanic eruption in human history was much
larger than previously thought, scientists say.
The Bronze Age eruption of Thera near mainland Greece would have
devastated ancient civilisations in the region.
Ash would likely have plunged much of the Mediterranean into
darkness, and tidal waves would have wrecked local ports.
A survey around what is now the island arc of Santorini shows
volcanic pumice to a depth of 80m covering the ocean floor for
20-30km in all directions.
A colossal scale
By examining echoes from volcanic deposits on the ocean floor,
researchers have shown that the Aegean eruption of Thera nearly 3,500 years
ago may have propelled 60 cubic km of magma out of the volcano's
crater.
The new estimates suggest that the blast was half as large again
as had earlier been supposed.
"It was clear that this was a very substantial eruption to begin
with, but this adds an exclamation mark," says Steven Carey of the
University of Rhode Island, US, a co-author on the study.
The eruption dwarfs even that of Krakatoa, which ejected about
25 cubic km of molten rock, ash and pumice in 1883, killing 40,000
inhabitants of Java and Sumatra in just a few hours.
Deadly tidal waves
An eruption of Thera's size would have had drastic implications
for the people living in the region.
No bodies were found in the nearby settlement of Akrotiri, which
was buried in ash in a similar way to Roman Pompeii. The city had
been evacuated shortly beforehand.
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