The role of volcanism in archaeology and cultural change in Japan is graphically demonstrated in Ibusuki, described by the excavator (Hamada, 1921) as the ‘Pompeii or Santorini of the prehistoric era in Japan’. In Ibusuki, Hamada demonstrated that the Jomon pottery types in use before the eruption were older and distinctly different from the Yayoi pottery found in the post-disaster stratigraphy. The volcanic disaster is therefore associated with a distinct change in the cultural assemblage.
Disaster archaeology in Japan can be broadly divided into four categories. The first category uses tephra to date cultural artifacts (Arai, 1971; Machida and Arai, 1992). The second category ignores tephra isochrones and develops typologies of cultural material retrieved from archaeological contexts and explores the cultural developments that may be apparent (Shinto, 1978). The third category focuses on disasters themselves and explores the nature of disaster events by examining related features such as villages buried by tephra deposits (Noto, 1983). The fourth category seeks to develop a theoretical understanding of the influences and processes of disasters by simulation. These methodological approaches, when used in a complementary fashion rather than in isolation, may reveal the essence of the volcanic disaster. These approaches are illustrated by a study of archaeology and tephras from the Jomon period in Southern Kyushu.
There have been many active volcanoes on Southern Kyushu, some of which are still active, such as Sakurajima volcano, and there are many distinct tephra isochrones that are of great value in archaeological research (Fig. 18.1). The ‘Akahoya’ tephra, erupted from the Kikai caldera, has helped establish the chronology of Jomon potteries on Kyushu. The cylinder-shape potteries of the first Jomon stage, while ubiquitous below, are not found above the tephra, whilst the Todoroki and Sobata type potteries are only found above the tephra (Machida and Arai, 1978; Shinto, 1978). The Akahoya tephra isochrone is widely distributed across Japanese islands, which has allowed the comparison of potteries from widely separated areas (Maizou-bunkazai-kenkyukai, 1987).