Recent progress in tephra studies in Japan and overseas

This paper aims to review the current situa-tion of tephra studies in Japan and overseas, focusing on methods of identification, dating, applications in palaeoclimatology, and develop-ment of archives of standard tephra samples. The author refers to recent intercomparison of tephrochronology laboratories with EPMA data on the geochemistry of volcanic glasses and developments notably in LA-ICP-MS that are revolutionizing the analysis of tephras. For determination of eruption ages of tephras, recent dating methods ranging from radiometric methods to age modeling tools such as ice-core-based age dating, together with palaeoclimato-logical studies are reviewed. In particular, the author overviews recent studies reporting detec-tions of intercontinentally distributed tephras identified in the Greenland ice core and related issues.