[thedoc (OP)]

Paul Green asked the Naked Scientists:
   
What are the similarities and differences of the term "blast radius" for nuclear explosions and volcanic eruptions?  I am particularly interested in the effects of the volcano on the island of Thera(now Santorini) in the Aegean and how it affected the island of Crete ~ 1500 BC
What do you think?

[Colin2B]

With a bomb the blast is a combination of a high energy heat/light wave followed by a pressure wave. An air burst will give a radius with little debris carried by the pressure wave, a ground burst will carry a small (comparatively) amount of debris but will not produce a circular zone due to the effects of surface topography e.g. Valleys/hills and differences in surface cover e.g. trees vs open ground.
Volcanoes also produce a pressure wave but virtually no heat/light wave. The pressure of the eruption also throws large amounts of debris for a considerable distance and it is often followed by large amounts of debris and hot gases which form a pyroclastic flow of about 1000C. Because this moves downhill, hugging the ground, the distance will vary with direction. Also, as with Mount St Helens, some eruptions are only concentrated on one side of the volcano.

[evan_au]

Santorini is about 150km from Crete.

The earthquake and noise accompanying an eruption of this magnitude would have been felt on Crete.

I expect the biggest immediate economic impact would have been from a tsunami striking Crete, as ocean waves in deep water carry energy efficiently over long distances.

Longer term, ash would have been carried relatively slowly on winds and landed on Crete, harming agriculture, but the depth of ash is estimated at only 5mm.

I have seen the Palace at Knossis on Crete, but it is unclear to me where the seat of Minoan culture lay. It is possible that the destruction of their city on Thera may have destabilized the culture. I am hoping to visit Santorini next year, so I may develop a first-hand impression then.

See: https://en.wikipedia.org/wiki/Minoan_eruption#Minoan_civilization