"In a very similar setting, [the milder] Krakatau produced 100-foot [30-meter] tsunami waves," Sigurdsson said.
Other pyroclastic flows would have been comprised of pumicea frothy rock so light it floats.
These flows, known as overwater flows, would have zoomed across the sea in scalding waves of debris, eventually hitting land many miles away.
An overwater flow from Krakatau killed more than a thousand people on the coast of Sumatra, 25 miles away from the site of the eruption.
The devastation caused by Santorinionce a single islandwould have been far worse.
"We have to scale the effects of both the tsunami and overwater pyroclastic flows to the Santorini eruption," Sigurdsson said.
His team, he adds, will soon begin studies in Crete and western Turkey looking for the remnants from such flows.
Jelle Zeilinga de Boer, an emeritus professor of geology at Wesleyan University in Middletown, Connecticut, notes that the strength of the eruption also depends on its duration.
"We don't know whether this came out in one flow or a number," he said.
There is some archaeological evidence, he adds, that people returned to the devastated area and started rebuilding, only to be blasted anew by the next round of activity.
Whether it occurred in one large blast or in a series of smaller events, the eruption produced massive devastation.
In his book Volcanoes in Human History, de Boer links the eruption to the demise of the Minoan civilization.
The seafaring Minoan culture was based on Crete, which is only a few dozen miles from Thera. At the time of the eruption, they dominated that part of the ancient Mediterranean.
When Thera erupted, the Minoans would have been clobbered by tsunamis, overwater pyroclastic flows, and fires from oil lamps knocked over by the eruption's shockwave.
Famine, plague, and a destruction of the Minoans' shipping economy would also have followed, de Boer says.
The eruption may also have had an enormous impact on Mediterranean mythology.
"I have no doubt that every myth is based on some event, and so is the myth of Atlantis," the University of Rhode Island's Sigurdsson said. "An event of this magnitude must have left its imprint."
Sigurdsson also sees traces of Santorini in a Greek poem called the Theogony, composed by Hesiod about 800 years after the eruption.
The poem describes an epic battle between giants and the Greek gods and includes imagery of a great battle far out at sea.
Hesiod must have picked up the story as folklore handed down from survivors close enough to see the event but not close enough to know what happened, Siggurdsson says.
"He uses all the terminology one would use in describing an eruption," he said. "The people who lived close enough to see that it was a volcano were all killed. [The rest] could only describe it in supernatural terms."
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