Geographical Information Regarding Jomon Period Shell Mounds Ruins in the Coastal Regions of Iwate Prefecture　－ Comparisons with tsunami inundation zones which occurred during the Great East Japan Earthquake －

岩手県域における縄文時代の貝塚の地理情報－東日本大震災による津波浸水域との比較－

Abstract
　Of the 116 archaeological sites that have been confirmed to be shell mounds in the area of northern Sanriku within Iwate Prefecture, 92 sites are ruins from the Jomon period.　8 of these shell mound ruins are from the Initial Jomon period, 39 from the Early Jomon period, 67 from the Middle Jomon period, 51 from the Late Jomon period, and 36 from the Final Jomon period. The largest number of ruins is from the Middle Jomon period.　When comparing the tsunami inundation zones during the Great East Japan Earthquake with the sites of shell mound ruins from the Jomon period in northern Sanriku, it was found that the tsunami had reached 35 sites.　There are 51 Jomon ruins where an analysis of surface geological features revealed that gravel may have been transported and deposited by large tsunamis (paleotsunamis) that had occurred after the Jomon period. 　Of the Jomon shell mound ruins where gravel was observed, the tsunami during the Great East Japan Earthquake had reached 18 sites.