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The Minoan eruption of Santorini volcano was a large-scale explosive
event that would have had significant consequences for the people
living in the eastern Mediterranean area. The principal effects
would have been widespread ash fallout, pyroclastic flow and surges
travelling over the sea, generation of tsunamis, and climatic cooling
in the year following the eruption |
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The eruption produced about 19 km3 (dense rock equivalent)
of pumice and ash fallout that was dispersed by the prevailing winds
over a large area of Mediterranean region. Studies of the distribution
of the volcanic ash layer from the eruption indicate that the majority
of the ash was transported to east where several tens of centimeters
of ash accumulated at distances up to 200 km from the volcano (fig.
1). During fallout an area of at least 300,000 km2 would
have been plunged into total darkness. |
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The volcanic deposits on Santorini indicate that pyroclastic flows
and surges were discharged into the ocean during the Minoan eruption.
Based on analogies with the recent 1883 eruption of Krakatau volcano
in Indonesia and the Soufriere Hills on Montserrat it is likely
that dilute parts of the flows were able to travel over the sea
surface for distances of tens of kilometers (fig. 2). These flows
would have been immediately lethal to any ships in the area or residents
on nearby islands. |
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The Minoan eruption discharged large volumes of pyroclastic flows
into the sea and resulted in the formation of a large submarine
caldera as the roof of the magma chamber collapsed in on itself.
Both processes are known to cause large and deadly tsunamis (fig.
3). During the 1883 eruption of Krakatau in Indonesia discharged
of pyroclastic flows into the sea and formation of a submarine caldera
generated tsnumis that crested at 30 m on the nearby coasts of Java
and Sumatra, resulting in the deaths of over 35,000 people. At Santorini
the generation of tsunamis would likely have had lethal effects
on nearby islands, including Crete to the south. |
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The Minoan eruption discharged at least 1.8 x 109 kg
of sulfur into the Earth’s atmosphere. This element combines
with OH- in the stratosphere to form sulfuric acid droplets. These
droplets block out incoming solar radiation resulting in a cooling
of the Earth’s surface. The formation of the droplets usually
takes place about 6-12 months following injection into the atmosphere
and thus cooling typically occurs about a year after an eruption.
Based on observed climatic effects of recent historic eruptions
the Minoan event likely produced a global cooling of about 0.35o
C |
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