Archaeological evidence for the tsunami of January 18, A.D. 749: a chapter in the history of Early Islamic Qâysariyah (Caesarea Maritima)

Deterioration of Israel's Caesarea Maritima's ancient harbor linked to repeated tsunami events identified in geophysical mapping of offshore stratigraphy

“…4). Much of this evidence comprises of shell layers described in the terrestrial excavations that were previously interpreted as dredge debris (see Dey et al 2014 for detailed discussion). However, thus far, only one offshore layer has been identified (Fig.…”

“…Evidence to support the role of tsunamis in this initial damage takes the form of laterally extensive sedimentary horizons with interpreted tsunamigenic characteristics (details follow below) recorded offshore, as well as reviews of archeological reports demonstrating the presence of corresponding deposits on land (Reinhardt et al, 2006;Goodman-Tchernov et al, 2009;Dey and Goodman-Tchernov, 2010;Dey et al, 2014). Reinhardt et al (2006) have characterized a tsunami deposit, found in an excavation trench (Area 'W', see Fig.…”

“…Their realization was that a wide range of distinctive stratigraphic evidence for tsunami-related deposits was present. Other sorts of interpretations had included construction fill or dredging refuse dump, but these were refuted in light of new tsunami characterizations (Dey and Goodman, 2010;Dey et al, 2014). In this paper, regional high-resolution seismic profiling offshore the harbor mouth of Caesarea is combined with ongoing marine archeological investigations to show the regional impact of multiple tsunamis on both this harbor and the adjacent coastline over the past two millennia.…”

“…Archeologists have been aware of these events for decades (see discussion in Dey et al, 2014), but they have lacked the comparative tools or reference data to ascribe particular deposits (onshore or offshore) to tsunami-derived causes. As a result, alternative explanations for these seemingly anomalous deposits found in archeological sites have been put forward.…”

“…Since then, a few studies of past and recent tsunami events and modeling have answered Rhodes' question in the affirmative as well. Some examples beyond the work in Caesarea (Reinhardt et al, 2006;Goodman-Tchernov et al, 2009, Dey and Goodman 2010, Dey et al 2014) include cores collected from Augusta Bay, Italy (de Martini et al, 2010;Smedile et al, 2012), offshore boulders mapped in western Banda Aceh, Indonesia (Paris et al 2009), Weiss and Bahlburg's (2006) modeling predictions suggesting the presence of deposits in the shallow offshore. The near offshore environment is still more poorly understood relative to terrestrial coastal areas.…”