[SunkenCiv]

There's no link between a volcanic eruption and the destruction of the Minoan sites -- that indicates the arrival of the Mycenaeans. Herodotus wrote a nice chunk about Calliste/There/Santorini and nothing about any eruption. The caldera is very prehistoric (10s or 100s of 1000s of years old, perhaps on the order of the age of the caldera at Kos), and from antiquity we've got just one account of an eruption, about 200 BC.

[Verginius Rufus]

There is a famous 2nd-millennium BC site on Thera which was excavated in the period after WWII. There are famous frescoes from the buildings there now in the National Archaeological Museum in Athens. It was covered by volcanic ash (like Pompeii). Some of the ash landed on Greenland and back in the 1980s someone calculated from Greenland ice cores that the ash dated to 1628 B.C. I think there is some quibbling about the exact date but definitely there was an eruption during the Bronze Age. Classical Greek historians are not reliable about what happened 1000 years earlier.

I don't know if we have any evidence for what language was spoken by the people on Thera before the eruption.