1 research outputs found
Archaeoseismic record at the ancient Roman City of Baelo Claudia (Cádiz, south Spain)
This study represents the first paleoseismic approach in Spain in which archaeological remains are considered. The ancient
Roman city of Baelo Claudia (1st–4th centuries AD), located at the axial zone of the Gibraltar Strait (Cadiz, south Spain),
contains abundant disrupted architectural relics and ground collapses (i.e. landsliding, liquefacion) probably related to historic
earthquake damage of intensity IX–X MSK. The archaeological stratigraphy of the city evidence two major episodes of abrupt
city destruction bracketed in AD 40–60 and AD 350–395 separated by an intervening horizon of demolition for city rebuilding,
otherwise characteristic for many earthquake-damaged archaeological sites in the Mediterranean. The second episode led the
eventual city abandonment, and it is evidenced by good examples of column collapse, distortion, failure and breakdown of
house and city walls, and pavement warping and disruptions documented during different archaeological excavations, which
can be catalogued as secondary coseismic effects. Main damaged relicts observable today are the set of pop-up like arrays and
warping developed in the ancient Roman pavement. Their analysis indicate an anomalous westwards ground displacement
oblique to the main gentle southward slope of the topography, as also evidence failures, collapses and breakdown of walls and
columns, suggesting that stress acted in a broad SW–NE/WSW–ENE orientation consistent whit the expectable motion along
the largest NE–SW strike-slip faults of the zone, which in turn can be catalogued as seismic sources of moderate events (ca. 5
mb). Major disruptions and city abandonment were hesitantly related to relatively far strong earthquakes occurred during the
late 4th century AD in the Mediterranean or western coast of Iberia by Menanteau et al. [Menanteau, L., Vanney, J.R., Zazo, C.,
1983. Belo II : Belo et son environment (Detroit de Gibraltar), Etude physique d’un site antique. Pub. Casa de Velazquez, Serie
Archeologie 4., Ed. Broccard, ParĂs.]. However, this study indicates that the occurrence of close moderate earthquakes jointly with the unstable character of the ground at the zone (site effect) is a more reliable hypothesis to explain the observed
deformations