Volcanic Eruptions - Tsunami - page 159

20 ° 30 ° 40 °

Black Sea

40 °

Cyprus

1

2

3

Turkey

Africa

Santorini

Greece 30°

Jaffa-Tel Aviv

Anapi

Sites of homogenites

4

Tsunami wave energy
concentrated by refraction

Rhodes

4

Tsunami wave energy
dispersed by refraction

Crete

Knossos

Direction of pumice drift

Fig. 8.5 Eastern Mediterranean region affected by the Santorini
eruption around 1470 BC. The numbers refer to sites where
homogenites exist (1) Calabrian Ridge (2) Ionian Abyssal Plain (3)

Bannock Basin, and (4) Mediterranean Ridge. Refraction patterns
based on Kastens and Cita ( 1981 )

of the legendary king Minos at Knossos, rivaling any other
Middle Eastern structure in size. The eruption of Santorini,
also known as Stronghyli—the round island—did not
destroy Minoan civilization, but it certainly weakened it.
The tsunami from the eruption is believed to have sunk
most ships near the coast and in harbors, and to have greatly
disrupted sea trade that was pivotal to the stability of the
civilization. Ash falls also disrupted agriculture. Within
50 years of the eruption of Santorini, the Mycenaean
Greeks, who had escaped its effects, were able to conquer
the Minoans and take over their cities and palaces.
Santorini volcano is part of a volcanic island chain
extending parallel to the coast of Asia Minor (Fig. 8.5 ). The
Aegean is the only zone in the eastern Mediterranean where
subduction of plate boundaries is active (Pichler and
Friedrich 1980 ; Druitt et al. 1999 ). Of all these volcanic
islands, only two, Santorini and Nisyros, have erupted in
recorded times. Santorini forms a complex of overlapping
shield volcanoes consisting of basaltic and andesitic lava
flows. The volcano has erupted explosively at least 12 times
during the last 200000 years. Its height has been reduced
over this time from a single mountain 1,500 m high to three
islands less than 500 m in height surrounding a submerged
caldera. The eruption around 1470 BC was the most recent
of these and was one of the largest eruptions on Earth in the

last 10000 years. The timing is debatable (LaMoreaux
1995 ). Acidity in Greenland ice cores suggest that the major
eruption occurred in 1390 ± 50 BC, although radiocarbon
dating on land suggests an age around 1450 or 1470 BC.
Dendrochronology based on Irish bog oaks and Californian
bristlecone pine puts the age of the event as old as 1628 BC.
At this latter time, Chinese records report a dim sun and
failure of cereal crops because of frost. Large volcanic
events cool temperatures globally by as much as 1 C over
the space of several years. The range of dates may not be
contradictory because there is evidence that Thera may have
erupted several times over a time span of 200 years.
The timing of the Santorini eruption has also been linked
to the plagues of Egypt (Exodus 6:28-14:31) and the exodus
of the Israelites from that country (Myles 1985 ; LaMoreaux
1995 ; Bryant 2005 ). In 1 Kings 6:1 the exodus is dated as
occurring 476 years before the rule of Solomon. Scholars
believe that Solomon began his rule in 960 BC, putting the
Exodus around 1436 BC. Other evidence indicates that the
exodus occurred in 1477 BC. Both dates encompass the
reign in Egypt of either Hatshepsut or her son Tuthmosis III
of the 18th dynasty. The transition of rule between the two
rulers is known as being a time of catastrophes. In the
biblical account, the river of blood may refer to pink pumice
from the Santorini eruption preceding the explosion. This