Human Response to Postglacial Sea Level Change in Jomon Prehistoric Sites Around Lake Ogawara, Northern Japan

ABSTRACT The Jomon culture, characterized by hunting, gathering, and fishing, lasted from approximately 15.5–2.4 ka in the Japanese archipelago. In this study, the shore of Lake Ogawara in northeastern Japan was investigated using coring, fossil analyses, and radiocarbon dating to reconstruct the palaeoenvironmental changes as well as their relationship with human activity. Postglacial sea‐level rise led to transgression and tidal delta formation around 10–8 ka. This resulted in the development and emergence of sandy tidal flats and inner‐bay environments that were favorable for shellfish. As a result, people settled near the shoreline and produced numerous shell middens. After ca. 7 ka, a slower sea‐level rise resulted in shallower water and the expansion of the sandy tidal flats. Consequently, there was a reduction in sandy tidal flats on the eastern and northeastern shores, and human habitation shifted to the southern and southwestern shores, where such environments persisted. After ca. 5–4 ka, further salinity reduction promoted the expansion of freshwater lakes and wetlands around the lake. At this stage, people shifted to exploiting the brackish water clam or moved toward the northern shore. These findings suggest that Jomon populations continually adapted to geomorphological changes, thereby sustaining and developing the Jomon culture.