Effects of the Minoan eruption on settlements and vegetation on Santorini

Description

Nikolaos Sigalas & Walter L. Friedrich

Due to an ideal find of olive trees that were buried alive in the pumice recently found on Santorini, the Minoan eruption could be dated by radiocarbon method to 1613±13 BC.  Since the growth place of the olive trees on the caldera wall and the prehistoric settlement at Akrotiri were buried by the deposits of the same eruption, the obtained age is valid for both sites.

The eruption was partly influenced by contact with sea water, which changes the eruption process. Consequently, damage on buildings and vegetation depended on the different eruption phases and on the distance of the sites from the eruption point.

The effects of the precursor phase were traceable on both sites: olive leaves embedded in volcanic dust, olive branches coated by fine pumice on the upper side. At Akrotiri Excavation many organic items were preserved in the same layer.

The first phase (air-fall pumice) buried most of the olive trees and kept them standing upright. Also walls of buildings were preserved in upright position. The deposits of the second phase (base surges) were laterally directed and expanded with high velocity from the crater and swept away all objects rising above the surface of the air fall layer. Thus, branches of the olive trees found were removed, and at Akrotiri walls were broken and laid down on top of the previous layer. The third eruption phase (ignimbrites or mud flows) hit both sites, but had no effect on the deeper laying objects that were buried by deposits of the previous phases.