Underwater geoarchaeological excavations on the shallow shelf (! 10 m depth) at Caesarea, Israel, have documented a tsu- nami 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 prob- ably triggered by an earthquake that destroyed Antioch, and was generated somewhere on the Cyprian Arc fault system. The tsu- nami 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 com- posed 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 op- tically 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 can- didate for the event, and the probable cause of the harbor destruction.

This article describes the microbial populations within the Levantine basin euxinic sediments and related geochemistry in two locations that differ in organic m

During the 2010–2011 E/V Nautilus exploration of the Levantine basin’s sediments at the depth of 300–1300 m, densely patched orange-yellow flocculent mats were observed at various locations along the continental margin of Israel. Cores from the mat and the control locations were collected by remotely operated vehicle system (ROV) operated by the E/V Nautilus team. Microscopic observation and phylogenetic analysis of microbial 16S and 23S rRNA gene sequences indicated the presence of zetaproteobacterial stalk forming Mariprofundus spp. – like prokaryotes in the mats. Bacterial tag-encoded FLX amplicon pyrosequencing determined that zetaproteobacterial populations were a dominant fraction of microbial community in the biofilm. We show for the first time that zetaproteobacterial may thrive at the continental margins, regardless of crustal iron supply, indicating significant fluxes of ferrous iron to the sediment-water interface. In light of this discovery, we discuss the potential bioavailability of sediment-water interface iron for organisms in the overlying water column.