Mili-microscale chemical analysis of tsunami deposits in Japan

2015 Fiscal Year Final Research Report

• Project/Area Number: 25630410
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Earth system and resources engineering
• Research Institution: Japan Atomic Energy Agency (2014-2015); Tohoku University (2013)
• Principal Investigator: Watanabe Takahiro 国立研究開発法人日本原子力研究開発機構, バックエンド研究開発部門 東濃地科学センター, 研究職 (40436994)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 津波堆積物 / 災害科学 / 地球化学 / 分析化学 / 土壌 / 東北地方

Outline of Final Research Achievements

To estimate past tsunami inundation area, we performed radiocarbon dating of plant fossils and inorganic geochemistry of tsunami deposits in lake and soil sediments from eastern Japan (Aomori, Miyagi and Shizuoka). The radiocarbon dating of the plant fossils were measured by accelerator mass spectrometry. Inorganic chemical analyses of tsunami deposit (about 1000-3000 cal BP) were carried out using X-ray fluorescence spectrometry, X-ray analytical microscope system and laser ablation inductively coupled plasma mass spectrometry. High sodium/titanium atomic ratios (more than 12) in tsunami deposits and enrichment arsenic just below the deposits were observed in this study. This study showed that chemical component (sodium, titanium, strontium, rubidium, barium, sulfur, arsenic) could be useful indicator for past tsunami deposits.

Free Research Field

地球化学