A wiggle-match age for the Millennium eruption of Tianchi Volcano at Changbaishan, Northeastern China

摘要

The Tianchi Volcano, located on the border between China and North Korea, produced a massive Plinian eruption of Volcanic Explosivity Index (VEI) 7 around 1000 AD, which is referred to as "the Millennium eruption of Tianchi Volcano" Until now, this volcanic eruption has not been well dated. In this paper, we report a series of new calibrated dates using wiggle-match dating from carbonized logs collected from fallout deposits on the southern and northern flanks of the Tianchi crater. Fifty AMS ~(14)C ages of tree rings from two logs were obtained for the Hengshan site, south of the Tianchi crater (Fig. 1). These yielded a high-precision wiggle-match date of 921-941 cal AD (95.4%) for the Millennium eruption. Thirty-two AMS ~(14)C ages of tree rings of other two logs from the Dongfanghong site, north of Tianchi crater (Fig. 1), produced an age range for the volcanic eruption from 921 to 942 cal AD (95.4%). A combined date for the four carbonized logs produced an age of 923-939 cal AD (95.4%) for the Millennium eruption. Moreover, an exact date of late autumn, 938 AD or early spring, 939 AD is suggested based on the impact of the Tianchi Volcano on global climate, especially East Asian climate, and the complete outermost rings of these four trees killed in the eruption.