Gloria I. López

The tsunami of 13 December A.D. 115 and the destruction of Herod the Great's harbor at Caesarea Maritima, Israel

Underwater geoarchaeological excavations on the shallow shelf (∼10 m depth) at Caesarea, Israel, have documented a tsunami that struck and damaged the ancient harbor at Caesarea. Talmudic sources record a tsunami that struck on 13 December A.D. 115, impacting Caesarea and Yavne. The tsunami was probably triggered by an earthquake that destroyed Antioch, and was generated somewhere on the Cyprian Arc fault system. The tsunami deposit consisted of an ∼0.5-m-thick bed of reverse-graded shells, coarse sand, pebbles, and pottery deposited over a large area outside of the harbor. The lower portion of the deposit was composed of angular shell fragments, and the upper portion of whole convex-up Glycymeris spp. shells. The sequence records tsunami downcutting (∼1 m) into shelf sands, with the return flow sorting and depositing angular shell fragments followed by oriented whole shells. Radiocarbon dating of articulated Glycymeris shells, and optically stimulated luminescence (OSL) dates, constrain the age of the deposit to between the first century B.C. and the second century A.D., and point to the tsunami of A.D. 115 as the most likely candidate for the event, and the probable cause of the harbor destruction.

New Quartz Optical Stimulated Luminescence Ages for Beach Ridges on the St. Vincent Island Holocene Strandplain, Florida, United States

Abstract St. Vincent Island, located on the northwest Gulf of Mexico coast of Florida, U.S.A., preserves a well-developed beach ridge plain that is generally believed to have begun to form during the mid-Holocene period. This study evaluates the potential of optical stimulated luminescence (OSL) to appraise the proposed evolution and progradation of this strand-plain. Optical stimulated luminescence was used to obtain the ages of the quartz samples extracted from seven vibracores at two depth intervals. The single-aliquot regenerative-dose (SAR) OSL ages increase from the shores on the Gulf of Mexico to St. Vincent Sound. The younger ridge set yielded ages of 370 ± 49 to 1890 ± 292 years (AD 2004 datum) conferring an interridge accretion time range of 78 to 148 years assuming uniform sediment accumulation. The oldest ridge set yielded ages of 2733 ± 404 to 2859 ± 340 years, consistent with the estimated age based on archaeological materials of 3000–4000 years ago. For the southwestern beach ridge set, the ages provide insights on the aeolian accumulation and reworking processes effective throughout the ridges despite their vegetation cover. Our results highlight the potential of OSL as an application to use not only for dating but also for coastal dynamics assessments. The SAR–OSL ages presented herein provide new reliable absolute ages on the beach ridge sequence of St. Vincent Island and improve the age control on formation of barrier island sequences in the Florida panhandle region.