The ancient Greeks may have built sacred or treasured sites deliberately on land previously affected by earthquake activity, according to a recent study by the University of Plymouth.
Professor of Geoscience Communication Iain Stewart MBE, Director of the University’s Sustainable Earth Institute, has presented several BBC documentaries about the power of earthquakes in shaping landscapes and communities.
Now, he believes that fault lines created by seismic activity in the Aegean region may have caused areas to be afforded special cultural status, and as such, led to their becoming sites of much celebrated temples and great cities.
Scientists have previously suggested Delphi, a mountainside complex once home to a legendary oracle, gained its position in Classical Greek society largely as a result of a sacred spring and intoxicating gases which emanated from a fault line caused by an earthquake.
But Professor Stewart believes Delphi may not be alone in this regard and that other ancient Greek cities including Mycenae, Ephesus, Cnidus, and Hierapolis may have been constructed specifically because of the presence of fault lines and earthquakes.
Many ancient Greek sites correspond to areas prone to earthquakes
In the study, published in Proceedings of the Geologists’ Association, Professor Stewart says a correspondence between active fault lines and earthquakes and ancient cities in parts of Greece and western Turkey might not seem unduly surprising given that the Aegean region is riddled with seismic faults and littered with ruined settlements.
Many seismic fault traces in the region do not simply disrupt the fabric of buildings and streets but run straight through the heart of the ancient Greek settlements’ most sacred structures.
There are prominent examples to support the theory, such as in Delphi itself, where an ancient Greek sanctuary was destroyed by an earthquake in 373 BC only for its temple to be rebuilt directly on the same fault line.
There are also many tales of individuals who attained oracular status by descending into the underworld, with some commentators arguing that such cave systems or grottoes caused by seismic activity may have formed the backdrop for these stories.
Why Greece has so much seismic activity
Greece lies in a highly seismically active region. The vast majority of earthquakes cause no damage or injuries.
The country is located in a complex boundary zone in the eastern Mediterranean between the African Plate and the Eurasian Plate.
The northern part of Greece lies on the Eurasian Plate while the southern part lies on the Aegean Sea Plate.
The Aegean Sea Plate is moving southwestward with respect to the Eurasian Plate at about 30 mm per year while the African Plate is subducting northward beneath the Aegean Sea Plate at a rate of about 40 mm per year.
The northern plate boundary is a relatively diffuse divergent boundary while the southern convergent boundary forms the Hellenic arc.
These two plate boundaries give rise to two contrasting tectonic styles, namely extension on east–west trending fault zones with strike-slip tectonics on SW-NE trending fault zones throughout west and central Greece, the Peloponnese, and the northern Aegean and contractional in the southern Aegean, continuing around to the Ionian islands.
The south Aegean is the location of the volcanic arc and is characterized by extension. To the east of Crete along the Hellenic Arc, strike-slip tectonics with some extension become important.