Is the Spili fault, Crete, responsible for the double destruction of the Minoan palace at Phaistos?
School of Mineral Resources Engineering, Technical University of Crete
This study explores the possible relationship between seismic activity on the Spili Fault in Crete and the double destruction of the Minoan Palace at Phaistos approximately 3750 and 3400 years Before Present (BP). The paleoearthquake activity on the Spili Fault is examined using a novel methodology that combines measurements of Rare Earth Elements (REE) and of in situ cosmogenic 36Cl on the exhumed fault scarp. Data show that the Spili Fault is active and has generated a minimum of five large-magnitude earthquakes over the last 16000 years.
The two most recent events occurred 200 and 400 years ago producing a cumulative displacement of 3.5 meters. The timing of the three older paleoearthquakes is constraint at 8200, 15000 and 16000 years BP with slip sizes of 2.5, 1.20 and 1.80 meters, respectively. The magnitude of the earthquakes that produced the measured co-seismic displacements range from M 6.3-7.3 and the average earthquake recurrence interval on the Spili Fault is about 3500 years. The above data not only suggest that no large-magnitude earthquake was generated by the Spili Fault during the Minoan period but, in contrast, during that period the fault experienced a long phase of seismic quiescence. Hence, our study shows that the hypothesis that there is a link between seismic movement on the Spili Fault and destruction of the Minoan Phaistos, does not seem to be corroborated, despite the fact that Spili is among the most active faults on Crete. The responsible fault is yet to be identified; here we propose two new candidate faults.