@article{oai:nagoya.repo.nii.ac.jp:00011592, author = {工藤, 崇 and Kudo, Takashi and 奥野, 充 and Okuno, Mitsuru and 中村, 俊夫 and Nakamura, Toshio}, journal = {名古屋大学加速器質量分析計業績報告書}, month = {Mar}, note = {The eruptive history of Kita-Hakkoda volcano group in the northeast Japan arc during the past 5000 years has been determined by tephra-stratigraphy and AMS ^<14>C dating. Kita-Hakkoda volcano group comprises eleven small-scale stratovolcanoes. We identified seven tephra layers (Hk-J1,Hk-J2,Hk-J3,Hk-1,Hk-2,Hk-3 and Hk-4 in descending order) erupted from this volcano group. The Hk-J1,Hk-J2,and Hk-J3 tephras were erupted from Jigokunuma Pond (100m in diameter) situated on the southwesterm foot of Odake volcano. The distributions of these tephras are limited the area within 300 m from the vent. These tephras were derived from phreatic eruptions. The magnitude of each eruption is less than 10^4 m^3 in volume. Judging from stratigraphic relation with the Towada-a tephra (AD 915), the eruption age of Hk-J1,Hk-J2 and Hk-J3 is estimated to be 500-400 years ago. The Hk-1,Hk-3 and Hk-4 tephras were erupted from the summit crater of Odake volcano. The source vent of the Hk-2 tephra may be Odake or ldodake volcano. The distribution of each tephra is restricted in 4-7 km from the vents. These tephras were derived from phreatic or vulcanian eruptions. The volume of these tephras ranges from 10^6 to 10^5 m^3. On the basis of radiocarbon dates, their ages are estimated to be 2.1 kyr BP for Hk-1,3.0 kyr BP for Hk-2,3.8 kyr BP for Hk-3 and 4.2 kyr BP for Hk-4., タンデトロン加速器質量分析計業績報告 Summaries of Researches Using AMS 1998 (平成10)年度}, pages = {218--234}, title = {北八甲田火山群における最近5000年間の噴火史}, volume = {10}, year = {1999} }