Evaluation of environmental change in the sediments under hypoxia revealed by non-destructive speciation of elements.

通过元素的非破坏性形态揭示缺氧下沉积物环境变化的评估。

• 批准号: 22310006
• 负责人: MATSUO Motoyuki
• 金额: $ 11.23万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2010
• 资助国家: 日本
• 起止时间: 2010-04-01 至 2014-03-31
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-22310006/
• 关键词: 貧酸素水塊; 東京湾; 堆積物; 浚渫窪地; メスバウアー分光法; X線吸収微細構造法; 放射化分析法; 放射性セシウム; 放射化分析; 非破壊状態分析; 硫酸還元菌

Hypoxia is water mass with little dissolved oxygen. This research aims at clarifying the scale of past hypoxia by the vertical analysis of sediments, assuming that the history of hypoxia is recorded on the bottom sediment. The dredged trench off Makuhari in Tokyo Bay has the maximum area and depth, and strong hypoxia has been observed there. Therefore, this area is suitable for an estimation of past hypoxia.The core sediments were collected from dredged trenches and non-dredged seabed as a reference site. We have applied Moessbauer spectroscopy and X-ray absorption fine structure, which are non-destructive state analysis, to every layer of the sediments obtained according to the sedimentation age. As a result, it is proved that the sedimentation environment of dredged trenches was specific and that the scale of hypoxia was decreasing. Moreover, paying attention to a relative concentration change of redox-sensitive elements, redox conditions at the time of deposition was evaluated.

缺氧是含有少量溶解氧的水团。本研究假设缺氧历史记录在底部沉积物上，通过沉积物的纵向分析来厘清过去缺氧的规模。东京湾疏海沟的面积和深度最大，且存在较强的缺氧现象。因此，这一区域适合用来估计过去的缺氧情况。岩心沉积物收集自疏浚的海沟和未疏浚的海床作为参考点。我们根据沉积年龄对每一层沉积物进行了非破坏性状态分析的Moessbauer光谱和x射线吸收精细结构。结果表明，疏浚海沟的沉积环境具有一定的特殊性，且缺氧规模呈减小趋势。同时，关注氧化还原敏感元素的相对浓度变化，评价沉积时的氧化还原条件。

项目成果

Determination of iron and manganese in the sediments under hypoxia with high time resolution

高时间分辨率缺氧条件下沉积物中铁和锰的测定

• 发表时间: 2012
• 期刊: KURRI Progress Report
• 作者: K. Shozugawa;T. Okoshi;T. Yamagata;R. Okumura;K. Takamiya and M. Matsuo
• 通讯作者: K. Takamiya and M. Matsuo

底質中のトリウム、セリウム、ウラン濃度を指標とした東京湾深堀内の貧酸素水塊の評価

以沉积物中钍、铈、铀浓度为指标评价东京湾深处缺氧水体

• 发表时间: 2012
• 期刊: 京都大学原子炉実験所専門研究会報告書
• 作者: Konno;U.;起 孝志・小森昌史・小豆川勝見・松尾基之
• 通讯作者: 起 孝志・小森昌史・小豆川勝見・松尾基之

Evaluation of hypoxia at dredged trenches in Tokyo Bay by determination of redox sensitive elements in the sediments

通过测定沉积物中的氧化还原敏感元素来评估东京湾疏浚沟槽的缺氧情况

• 发表时间: 2013
• 作者: T. Yamagata;K. Shozugawa;R. Okumura;K. Takamiya and M. Matsuo
• 通讯作者: K. Takamiya and M. Matsuo

Evaluation of hypoxia at dredged trenches in Tokyo Bay by determination of Fe and Mn in the sediments.

通过测定沉积物中的铁和锰来评估东京湾疏浚沟槽的缺氧情况。

• 发表时间: 2013
• 期刊: KURRI Progress Report
• 作者: T. Yamagata;K. Shozugawa;R. Okumura;K. Takamiya and M. Matsuo
• 通讯作者: K. Takamiya and M. Matsuo

Evidence for a weakening'dead zone'in Tokyo bay over the past 30years

过去30年东京湾“死亡区”减弱的证据

• DOI: 10.1007/s10751-011-0463-9
• 发表时间: 2012
• 期刊: Hyperfine Interactions
• 作者: K. Shozugawa;N. Hara;Y. Kanai and M. Matsuo
• 通讯作者: Y. Kanai and M. Matsuo