This day’s Centerfault is the Sparta Fault in southern Greece (37.1°N 23.3°E). Being situated on the Peloponessus, the fault marks one of the most prominent geomorphological features of the peninsula. It is famous for the historical 464 BC earthquake that destroyed ancient Sparta. However, the days of Spartian glory ended much later after a severe military defeat in the battle of Leuctra in 371 BC, Sparta never fully recovered.
The fault can easily be found in the field as it follows the base of a large mountain chain; triangular facets and hanging valleys are beautifully developed. A prominent fault scarp can be seen at various places. Sometimes, you will notice scars in the planar free face, caused by sampling for cosmogenic 36Cl datings. The results were published by Benedetti et al., 2002.
The authors found five historical earthquakes on the fault scarp and calculated an average recurrence period of 2800 +/- 300 yrs. Since the last event was the EQ in 464 BC, a future strong event must be expected. In 1991, Armijo et al. already claimed the more than 22 km long, N-S trending Sparta fault as the causative fault for the famous historic event.
Another funny fact is that a fountain was modelled into the fault surface. It’s a fault bound spring, belonging to a small chapel and recreation area at the fault scarp:
Armijo, R., Lyon-Caen, H. & Papanastassiou, D. 1991. A possible normal-fault rupture for the 464 BC Sparta earthquake. Nature 351, 137 – 139; doi:10.1038/351137a0.
Benedetti, L., Finkel, R., Papanastassiou, D., King, G., Armijo, R., Ryerson, F., Farber, D. & Flerit, F. 2002. Post-glacial slip history of the Sparta fault (Greece) determined by 36Cl cosmogenic dating: evidence for non-periodic earthquakes. Geophysical Research Letters 29, 8, 87 1-4, doi:10.1029/2001GL014510.
Papanastassiou, D., Gaki-Papanastassiou, K. & Maroukian, H. 2005. Recognition of past earthquakes along the Sparta fault (Peloponnesus, southern Greece) during the Holocene, by combining results of different dating techniques. Journal of Geodynamics 40, 189 – 199.