Osamu Tadai
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View article: Effect of particle characteristics on granular friction evaluated by dual-slip-plane friction tests
Effect of particle characteristics on granular friction evaluated by dual-slip-plane friction tests Open
The frictional properties of natural granular materials are important for understanding dynamic natural phenomena such as earthquakes and landslides. The coefficient of friction for natural granular materials varies significantly based on …
View article: Degradation of Excavated PVC Toys and Their Role as Technofossils in the Anthropocene
Degradation of Excavated PVC Toys and Their Role as Technofossils in the Anthropocene Open
View article: Correlation between induced polarization and sulfide content of rock samples obtained from seafloor hydrothermal mounds in the Okinawa Trough, Japan
Correlation between induced polarization and sulfide content of rock samples obtained from seafloor hydrothermal mounds in the Okinawa Trough, Japan Open
The physical properties of seafloor massive sulfides are crucial for interpreting sub-seafloor images from geophysical surveys, shedding light on the evolution of seafloor mineral deposits. While some studies have explored the relationship…
View article: The <i>Miharaishi</i> slate in Kochi Prefecture, Japan: Geological features of the source rock for Tosa-suzuri inkstone of Gendani
The <i>Miharaishi</i> slate in Kochi Prefecture, Japan: Geological features of the source rock for Tosa-suzuri inkstone of Gendani Open
Tosa-suzuri inkstone of Gendani, a traditional craft product of Kochi Prefecture, Japan, has been produced in Mihara Village, Hata District, using the Miharaishi slate that occurs in the Shimanto Belt. The slate-bearing sequence was though…
View article: Origins of sediments and fluids in submarine mud volcanoes off Tanegashima Island, northern Ryukyu Trench, Japan
Origins of sediments and fluids in submarine mud volcanoes off Tanegashima Island, northern Ryukyu Trench, Japan Open
Mud volcanoes are topographic features through which over-pressurized sediments are intruded upward and erupted, transporting fluids and sediments from the deep subsurface to the surface/seafloor. To understand material and biogeochemical …
View article: Correlation between induced polarization and sulfide content of rock samples obtained from seafloor hydrothermal mounds of the Okinawa Trough, Japan
Correlation between induced polarization and sulfide content of rock samples obtained from seafloor hydrothermal mounds of the Okinawa Trough, Japan Open
Physical properties of seafloor massive sulfides provide a basis for interpreting of sub-seafloor images obtained from geophysical surveys. They are useful for elucidating the evolution of seafloor mineral deposits. A few reports have desc…
View article: Influence of Pressure Generation Rate on Both Pore Size Distribution Measured by Mercury Porosimetry and Predicted Permeability
Influence of Pressure Generation Rate on Both Pore Size Distribution Measured by Mercury Porosimetry and Predicted Permeability Open
岩石の空隙径とその体積頻度分布は，岩石中を流れる流体の流れやすさの重要な指標である．空隙径分布を測定する方法の一つに水銀圧入法があるが，再現性および測定しやすさから現在も多くの分野で活用されている．一方，水銀の昇圧速度や昇圧方法の違いによる影響についてはあまり議論されていなかった．そこで4種類の岩石試料を用いて空隙径分布の昇圧速度依存性を評価した．連続昇圧実験と多段階ステップ昇圧実験の結果に大きな違いは認められなかった．花崗岩とドレライトは浸透率が小さいにも関わらず大きい空…
View article: Temperature response of water-saturated compact Longmenshan limestone and porous Rajasthan sandstone to changes in confining pressure
Temperature response of water-saturated compact Longmenshan limestone and porous Rajasthan sandstone to changes in confining pressure Open
Three data sets are stored in this data submission. The first data set includes the temperature response of water-saturated compact Longmenshan limestone (L27) and porous Rajasthan sandstone (RJS) to changes in confining pressure under dra…
View article: Temperature response of water-saturated compact Longmenshan limestone and porous Rajasthan sandstone to changes in confining pressure
Temperature response of water-saturated compact Longmenshan limestone and porous Rajasthan sandstone to changes in confining pressure Open
Three data sets are stored in this data submission. The first data set includes the temperature response of water-saturated compact Longmenshan limestone (L27) and porous Rajasthan sandstone (RJS) to changes in confining pressure under dra…
View article: Thermal Conductivity Profile in the Nankai Accretionary Prism at IODP NanTroSEIZE Site C0002: Estimations From High‐Pressure Experiments Using Input Site Sediments
Thermal Conductivity Profile in the Nankai Accretionary Prism at IODP NanTroSEIZE Site C0002: Estimations From High‐Pressure Experiments Using Input Site Sediments Open
Depth profiles of sediment thermal conductivity are required for understanding the thermal structure in active seismogenic zones. During the Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE), a scientific drilling project of the Inte…
View article: Thermal conductivity profile in the Nankai accretionary prism at IODP NanTroSEIZE Site C0002: estimations from high-pressure experiments using input site sediments
Thermal conductivity profile in the Nankai accretionary prism at IODP NanTroSEIZE Site C0002: estimations from high-pressure experiments using input site sediments Open
Depth profiles of sediment thermal conductivity are required for understanding the thermal structure in active seismogenic zones. During the Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE), a scientific drilling project of the Inte…
View article: Thermal conductivities of input site sediments from IODP Site 333-C0012 and 315-C0002
Thermal conductivities of input site sediments from IODP Site 333-C0012 and 315-C0002 Open
Two data sets are stored in this data submission. The first data set includes thermal conductivities of core samples measured under high confining and pore pressures from the sediments in IODP drilling site C0012 that overlay the in-coming…
View article: Geophysical constraints on microbial biomass in subseafloor sediments and coal seams down to 2.5 km off Shimokita Peninsula, Japan
Geophysical constraints on microbial biomass in subseafloor sediments and coal seams down to 2.5 km off Shimokita Peninsula, Japan Open
View article: Data Report for quantitative analysis of mineral composition using powdered X-ray diffraction method and RockJock program
Data Report for quantitative analysis of mineral composition using powdered X-ray diffraction method and RockJock program Open
岩石や堆積物を構成する鉱物の定量評価手法の一つとしてX線粉末回折データを用いた方法がある．米国地質調査所のEberl（2003）によって開発されたRockJockプログラムは無料で配布されていて，Excelマクロをベースとしたソルバーのため，比較的簡便に利用できる．定量可能な鉱物は90種以上もあるため，ほとんどの海底下掘削試料の分析に対応できる．一方，プログラムの解析精度と問題点についてはこれまであまり議論されてこなかった．さらに，微少量しか採取できない試料や，断層帯などに…
View article: Thermal conductivity changes in subducting basalt, Nankai subduction zone, SW Japan: An estimation from laboratory measurements under separate high-pressure and high-temperature conditions
Thermal conductivity changes in subducting basalt, Nankai subduction zone, SW Japan: An estimation from laboratory measurements under separate high-pressure and high-temperature conditions Open
Knowledge of rock thermal conductivity is necessary to understand the thermal structure in active seismogenic zones such as the Nankai Trough subduction zone, SW Japan. To estimate in situ thermal conductivity at the oceanic crust surface …
View article: Depth profiles of resistivity and spectral IP for active modern submarine hydrothermal deposits: a case study from the Iheya North Knoll and the Iheya Minor Ridge in Okinawa Trough, Japan
Depth profiles of resistivity and spectral IP for active modern submarine hydrothermal deposits: a case study from the Iheya North Knoll and the Iheya Minor Ridge in Okinawa Trough, Japan Open
Submarine hydrothermal deposits are one of the promising seafloor mineral resources, because they can store a large amount of metallic minerals as sulfides. The present study focuses on the electrical properties of active modern submarine …
View article: Experimental and numerical investigation of the temperature response to stress changes of rocks
Experimental and numerical investigation of the temperature response to stress changes of rocks Open
The temperature response to stress changes of rocks is key to understanding temperature anomalies in geoscience phenomena such as earthquakes. We developed a new hydrostatic compression system in which the rock specimen center can achieve …
View article: Electrical resistivity measurements of rocks under confining pressure condition
Electrical resistivity measurements of rocks under confining pressure condition Open
電気・電磁探査や孔内電気検層の比抵抗データを高い精度で解釈するためには，地下あるいは海底下の圧力・温度を再現した状態での掘削コア試料による比抵抗測定が必要不可欠である．本研究では圧力と比抵抗の関係について検討するため，封圧および間隙水圧を制御した状態で比抵抗測定ができるシステムを構築し，35 g/L塩化ナトリウム溶液で飽和した4種類の砂岩試料および2種類の火成岩試料について，最大80 MPaの有効拘束圧（間隙水圧：1 MPa）まで段階的に加圧したときの比抵抗を測定した．また…
View article: Trace element anomaly in fault rock induced by coseismic hydrothermal reactions reproduced in laboratory friction experiments
Trace element anomaly in fault rock induced by coseismic hydrothermal reactions reproduced in laboratory friction experiments Open
Friction experiments at high velocities (0.1 to 0.4 m/s) at room temperature under high pore fluid pressures (2 or 5 MPa) and trace element analyses of the run products were carried out on simulated fault gouge derived from the Chelungpu f…
View article: An Experimental Study on Measurement Methods of Bulk Density and Porosity of Rock Samples
An Experimental Study on Measurement Methods of Bulk Density and Porosity of Rock Samples Open
Density and porosity are fundamental and important physical properties of rocks in various geological problems, and affect the other physical properties. Therefore, measurements of density and porosity of rock samples are important investi…
View article: Experimental examination for electrical resistivity measurement using the alternative current impedance method
Experimental examination for electrical resistivity measurement using the alternative current impedance method Open
交流インピーダンス法による室内比抵抗測定は,電気探査や電気検層の比抵抗データの解釈,あるいは岩石や堆積物の基本的な電気的性質を明らかにするための有効な手段である.本研究では,交流インピーダンス法(二極法および四極法)による比抵抗測定の精度およびその有効性を検討するため,抵抗が既知の抵抗器(実験1),比抵抗が既知の電解質溶液(実験2),および海洋掘削コアを含む地質試料(実験3)を用いた実験を行った.実験1では,本測定システムの精度が装置の基本精度と同等であることを確認した.実…