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release by dry-wet cycles永野 博彦*; 鈴木 優里*; 平舘 俊太郎*; 安藤 麻里子; 小嵐 淳
no journal, ,
Global warming-induced changes in precipitation amplify the dry-wet cycles in soils. Those dry-wet cycles are well cautioned to stimulate carbon dioxide (CO) release from soils. However, our knowledge about this effect is still limited. Our soil incubation experiment revealed a comprehensive increase in soil CO release by dry-wet cycles and substantial variations in these CO release increase (1.3 to 3.7 folds greater than CO release under control conditions) among soils. Among the soil physiochemical properties investigated, pyrophosphate extractable aluminum contents showed a positive correlation with the CO release increase by dry-wet cycles. Soil organic carbon content-specific CO release showed a negative correlation with the CO release increase. These results suggest that organo-mineral complex can be a significant predictor for the dry-wet cycles-induced increase in soil CO release.
release increase under dry-wet cycles鈴木 優里*; 永野 博彦*; 平舘 俊太郎*; 安藤 麻里子; 阿部 有希子; 小嵐 淳; 中山 理智
no journal, ,
Recently, precipitation patterns are changing to less frequent events but stronger intensities with the progress of global warming. Such changes in precipitation raise concerns about increasing dry-wet cycles and CO release in soil. However, the mechanisms of soil CO release increase by dry-wet cycles are still unclear. In our soil incubation experiment for ten soils, dry-wet cycles significantly increased the CO release rate for all soils. Microbial biomass for all soils were significantly lower under the dry-wet cycles than under the constant moisture conditions. Quantitative PCR showed that fungal DNA concentrations were significantly lower under the dry-wet cycles. These results may suggest that the CO release increase is associated with soil microbial fluctuations caused by the dry-wet cycles.
Battulga, B.; 中西 貴宏; 安藤 麻里子; 小嵐 淳
no journal, ,
水圏中プラスチックは環境負荷物質の輸送媒体となるため、放射性物質移行を考慮する上でプラスチックとの相互作用を明らかにすることは重要である。2011年の東日本大震災に伴い発生した福島第一原子力発電所事故により環境中に放射性物質が流出したことを考慮し、本研究では放射性セシウム(
Cs)とプラスチックの相互作用を明らかにすることを目的とした。福島県の複数の河川において、プラスチックと河川底土の試料を採取した。プラスチックに付着したバイオフィルムを抽出するため、新規に開発した超音波アシスト抽出技術を適用した。バイオフィルム及び河川底土中のCs濃度は、ガンマ線スペクトロメトリで測定した。その結果、沿岸河川においてプラスチックが放射性物質の輸送媒体となることが示唆された。
Cs in a river-sea system boundary area高田 兵衛*; 和田 敏裕*; 脇山 義史*; 平尾 茂一*; 佐藤 俊*; 青野 辰雄*; 中西 貴宏; 御園生 敏治; 尻引 武彦
no journal, ,
The Cs sorption behavior on suspended particles was studied in river and coastal seawater, Fukushima Prefecture from June 2019 to October 2021. Although the suspended particle concentration was lower in the river than in seawater, the Cs activity on suspended particles in the river lager than that in seawater. Proportions of ion-exchangeable, organically bound, and refractory fractions of Cs on suspended particles were also determined by conducting sequential extraction method. The ion-exchangeable fraction was less than 1% at both areas. The organically bound fraction was a few %, resulting in that the refractory fraction accounted for 
90%. Thus, it is indicated that the mobility of Cs to marine biota is low in the studied areas.
下茂 道人*; 丹羽 正和; 宮川 和也; 安江 健一*; 徳永 朋祥*; 戸野倉 賢一*; Biraud, S.*
no journal, ,
本研究では、幌延地域の断層や褶曲を事例対象として、可搬型高精度ガス測定によって断層や褶曲における地下からのガス移行経路を把握するための調査技術の検証を行い、その有効性を示すことができた。
Malatesta, L.*; Huppert, K.*; 末岡 茂; Finnegan, N.*; Asiedu, R.*; Weiss, N.-M.*
no journal, ,
A dataset of over 6000 wave-cut marine terraces of presumed Last Interglacial high-stand age (~120 ka) around the Japan islands provides an unprecedented access to the controls on the generation and preservation of marine terraces. The data is a subset from the Atlas of Marine Terraces later digitized, and carefully corrected and redrawn by ourselves. The terrace dataset is complemented by wave power estimates from NOAA WaveWatch III and bedrock lithology information from the Geological Survey of Japan. Each individual terrace is matched with topographic information, local wave condition, lithology, and local relief. Along the subductions, terraces show an increase in elevation toward the trench reflecting non-recoverable deformation linked to the earthquake cycle. On the back arc side, terrace elevation can vary between ~0 and 150 masl over short distances (
20 km). We can identify the signature of the Niigata-Kobe Tectonic Zone responsible for the small block tilting noted by Ota and Yoshikawa (1978) along the coast of the back arc. Ongoing study of the dataset provides valuable insights to universal controls on marine terrace creation and preservation. We use their elevations as an indicator of relative patterns in rock uplift (precise ages and corresponding sea level stage are rarely available). At the time of abstract submission, we have identified the following: There are no large terraces preserved at low elevation as waves may more easily erode platforms residing in or near the swash zone. Terrace surface area reaches a maximum around 30 masl before declining again with higher elevation because faster rock uplift rates may reduce the time that waves have to erode any given bedrock elevation. The minimum area of terraces increases with elevation as subaerial erosion processes would tend to be more efficient under faster rock uplift. Lithology does not play a first-order role in controlling the distribution of terraces across elevation and wave power.
高井 静霞; 三箇 智二*; 島田 太郎; 武田 聖司
no journal, ,
中深度処分の安全評価(評価期間~10
年: 氷期・間氷期1サイクル)では、将来の長期にわたる地形変化の予測が不可欠である。沿岸域で将来の海水準変動の不確かさを考慮した評価を行うには、地形発達モデル(Landscape evolution models: LEMs)に基づく数値解析が有用と考えられる。しかし十万年スケールのLEMsの適用性は、沿岸域では検証されていない。原子力機構では、斜面域・河川域での土砂移動、テクトニクス、海域での堆積、気候・海水準変動、地質分布を考慮した、地形変化評価コード(JAEAsmtp)の開発を進めている。本研究では、本コードの最終氷期-間氷期サイクルにおける沿岸域の地形変化への適用可能性を検討した。対象地域は海成段丘(MIS5e, 7, 9)が広く分布する、上北地域(堆積岩地域)の一流域(解析範囲: 250km
)である。はじめに、海成段丘およびボーリング・音波探査データに基づき、標高(現地形及び古地形)・隆起速度・沖積層厚分布を推定した。次に、実地形および土質試験データから、LEMsのパラメータ値(河川侵食及び地質の受食性)を推定した。最後に、MIS5e(12.5万年前)から現在までの地形変化をシミュレートした。評価の結果、JAEAsmtpに新たに漂砂を導入することで、現在の汀線位置・堆積厚分布(埋没谷深度)を再現できる可能性を確認した。