The AD 365 earthquake. From legend to modelling


Α. Γ. ΔΡΑΚΟΣ
Σ. Κ. ΣΤΕΙΡΟΣ
Résumé

A major earthquake shook the entire East Mediterranean region on July 21st AD 365; numerous cities were completely ruined or seriously damaged, while a tsunami that followed destroyed the Nile Delta. This disaster impressed ancient writers for more than 1000 years and it turned to a legend. Despite the fact that the AD 365 earthquake is probably the greatest one that took place in the East Mediterranean region in the historic period, it has not been studied in detail. The main reason is that the historical data are poor, ambiguous and contradictory, and do not permit any secure seismological conclusions. Yet, many workers have concluded that this earthquake was associated with a fault along the Hellenic Arc, SW of Crete, in agreement with geomorphological, biological and radiometric data indicating that the western part of the island was uplifted by up to 9m by an earthquake in the 4th century AD. New archaeological data permit to shed more light to this earthquake and to identify its meizoseismal area, extending from western Cyprus to the Libyan coasts. Furthermore, an elastic dislocation analysis of the earthquake uplift, deduced from coastal data, permits to conclude that the causative fault was an east-west striking inverse fault at least 100km long, southwest of Crete, associated with an earthquake of magnitude of the order of M=8.5-8.7.

Article Details
  • Rubrique
  • Seismology
Téléchargements
Les données relatives au téléchargement ne sont pas encore disponibles.
Références
AMBRASEYS, Ν., MELVILLE, C. AND ADAMS, R. 1994. The seismicity of Egypt, Arabia and the Red Sea. Cambridge University Press.
DIVITA, Α., 1995. Archaeologists and earthquakes: the case of 365 A.D. Annali di Geofìsica, 38, 971-976.
FEIGL, Κ., DUPRE, E., 1999. RNGCHN: a program to calculate displacement components from dislocations on an elastic half-space with applications for modeling geodetic measurements of crustal deformation. Computers and Geosciences. 25, 695-704.
GUIDOBONI, E., COMASTRI, A. AND TRAINA, G., 1994. Catalogue of ancient earthquakes in the Mediterranean area up to 10th century. Istituto Nazionale di Geofisica, Roma, 504 pp.
JACQUES, F., BOUSQUET, Β., 1984. Le cataclysme du 21 Juillet 365: Phénomène regional ou catastrophe cosmique In: Tremblements de terre: Histoire et archeologie. IVemes rencontres internationales d'archeologie et d'histoire d'Antibes. Association pour la promotion et la diffusion des connaissances archéologiques, Valbonne, 183-198.
KELLETAT, D., 1991. The 1550 BP tectonic event in the Eastern Mediterranean as a basis for assessing the intensity of shore processes. Z. Geomorph. N. F., Suppl.-Bd., 81, 181-194.
LABOREL, J. AND LABOREL-DEGUEN, E, 1994. Biological indicators of Holocene sea-level variations and of co-seismic displacement in the Mediterranean area. J. Coast. Res., 10, 395-415.
OKADA, Y., 1985. Surface deformation due to shear and tensile faults in a half soace. Bull. Seism. Soc. America. 75, 1135-1154.
ΠΑΠΑΖΑΧΟΣ, B., 1997. Εισαγωγή στη σεισμολογία. Εκδόσεις Ζήτη, Θεσσαλονίκη.
PAPAZACHOS, B.C., 1996. Large seismic faults in the Hellenic arc. Annali di Geofìsica, 39, 891-903.
PAPAZACHOS, Β. AND PAPAZACHOU, C, 1997. The earthquakes of Greece. Zitis, Thessaloniki, 304 pp.
PIRAZZOLI, P., J. THOMMERET, Y. THOMMERET, J. LABOREL AND MONTAGIONNI, L., 1982. Crustal block movements from Holocene shorelines: Crete and Antikythira (Greece), Tectonophysics, 68, 27-43.
PIRAZZOLI, P., AUSSEIL-BADIE, J., GIRESSE, P., HADJIDAKI, E. AND ARNOLD, M., 1992. Historical environmental changes at Phalasarna harbor, west Crete. Geoarchaeology, 7, 371-392.
PIRAZZOLI, P., LABOREL, J., STIROS, S., 1996. Earthquake clustering in the Eastern Mediterranean during historical times. J. Geophys. Res., 101, 6083-6097.
SIEBERG Α., 1932. Erdbebengeographie. In: Β. Gutenberg (ed.), Handbuch der Geophysik. Berlin, 4, 3, pp. 687- 1005
STIROS, S., 1996. Late Holocene relative sea-level changes in SW Crete: evidence of an unusual earthquake cycle. Annali di Geofìsica, 39, 677-687.
STIROS, S., 2001. The AD 365 Crete earthquake and possible seismic clustering during the 4-6"1 centuries AD in the Eastern Mediterranean: a review of historical and archaeological data. J. Structural Geol, 23, 545-562.
STIROS, S., PAPAGEORGIOU, S., 2001. Seismicity of Western Crete and the destruction of the town of Kisamos at AD 365: Archaeological evidence. J. Seismology, (in press)
STIROS, S., DRAKOS, Α., 2000. Geodetic constraints on the fault pattern of the 1978 Thessaloniki (Northern Greece) earthquake (Ms = 6.4). Geophys. J. Int., 143, 679-689.
ΣΤΕΙΡΟΣ, Σ., ΠΑΠΑΓΕΩΡΓΙΟΥ, Σ., ΜΑΡΚΟΥΛΑΚΗΣ, Σ., 2001. Καταστροφή των Κρητικών πόλεων το 365 μ.Χ. Πρακτικά Συνεδρίου: Creta romana e protobizantina (υπό δημοσίευση).
ΤΑΥΜΑΖ, T., JACKSON, J. AND WESTAWAY, R., 1990: Earthquake mechanisms in the Hellenic Trench near Crete. Geophys. J. Int., 102, 695-731.
THOMMERET, Y, Y THOMMERET, J. LABOREL, L. MONTAGGIONI AND P. PIRAZZOLI, 1981. Late Holocene shoreline changes and seismotectonic displacements in western Crete (Greece). Z. Geomorph. Suppl. 40, 127-149.