Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Yamada Yasuhiro Last modified date:2022.04.19

Professor / Energy Resource Engineering / Department of Earth Resources Engineering / Faculty of Engineering

1. Yoshitaka Hashimoto, Shigeyuki Sato, Gaku Kimura, Masataka Kinoshita, Ayumu Miyakawa, Gregory F. Moore, Masaru Nakano, Kazuya Shiraishi, Yasuhiro Yamada, Decollement geometry controls on shallow very low frequency earthquakes, SCIENTIFIC REPORTS, 10.1038/s41598-022-06645-2, 12, 1, 2022.02, Recent studies have documented the occurrence of shallow very low frequency earthquakes (VLFE) in subduction zones. The heterogeneity of the materials or stresses that act on the plate interface results in the variable slip rate. Stress on the décollement can be controlled by the décollement geometry and the regional stress, which is also able to control the material properties. We determined the distribution of stress along the shallow portion of the décollement in the Nankai Trough using a three-dimensional (3D) seismic survey and regional stress analysis to construct maps of normalized slip tendency (Ts′) and dilation tendency (Td). Alignments of VLFEs trend parallel to the trends of T′s and Td. On the other hand, very low T′s and Td areas probably act as barriers that limit the number of VLFEs that can migrate towards the trench. Because the T′s and Td distributions are derived only from the décollement geometry and the regional stress without incorporating any data on sediment properties, the consistency between the trends suggests that the décollement geometry is the primary control on VLFE activity..
2. Massaro, L., Adam, J., Jonade, E., Yamada, Y., New granular rock-analogue materials for simulation of multi-scale fault and fracture processes, GEOLOGICAL MAGAZINE, 10.1017/S0016756821001321, 2021.12, In this study, we present a new granular rock-analogue material (GRAM) with a dynamic scaling suitable for the simulation of fault and fracture processes in analogue experiments. Dynamically scaled experiments allow the direct comparison of geometrical, kinematical and mechanical processes between model and nature. The geometrical scaling factor defines the model resolution, which depends on the density and cohesive strength ratios of model material and natural rocks. Granular materials such as quartz sands are ideal for the simulation of upper crustal deformation processes as a result of similar nonlinear deformation behaviour of granular flow and brittle rock deformation. We compared the geometrical scaling factor of common analogue materials applied in tectonic models, and identified a gap in model resolution corresponding to the outcrop and structural scale (1-100 m). The proposed GRAM is composed of quartz sand and hemihydrate powder and is suitable to form cohesive aggregates capable of deforming by tensile and shear failure under variable stress conditions. Based on dynamical shear tests, GRAM is characterized by a similar stress-strain curve as dry quartz sand, has a cohesive strength of 7.88 kPa and an average density of 1.36 g cm(-3). The derived geometrical scaling factor is 1 cm in model = 10.65 m in nature. For a large-scale test, GRAM material was applied in strike-slip analogue experiments. Early results demonstrate the potential of GRAM to simulate fault and fracture processes, and their interaction in fault zones and damage zones during different stages of fault evolution in dynamically scaled analogue experiments..
3. Tatsuo Nozaki, Toshiro Nagase, Yutaro Takaya, Toru Yamasaki, Tsubasa Otake, Kotaro Yonezu, Kei Ikehata, Shuhei Totsuka, Kazuya Kitada, Yoshinori Sanada, Yasuhiro Yamada, Jun-ichiro Ishibashi, Hidenori Kumagai, Lena Maeda, Subseafloor sulphide deposit formed by pumice replacement mineralisation, Scientific Reports, 10.1038/s41598-021-87050-z, 11, 1, 2021.12, AbstractSeafloor massive sulphide (SMS) deposits, modern analogues of volcanogenic massive sulphide (VMS) deposits on land, represent future resources of base and precious metals. Studies of VMS deposits have proposed two emplacement mechanisms for SMS deposits: exhalative deposition on the seafloor and mineral and void space replacement beneath the seafloor. The details of the latter mechanism are poorly characterised in detail, despite its potentially significant role in global metal cycling throughout Earth’s history, because in-situ studies require costly drilling campaigns to sample SMS deposits. Here, we interpret petrographic, geochemical and geophysical data from drill holes in a modern SMS deposit and demonstrate that it formed via subseafloor replacement of pumice. Samples from the sulphide body and overlying sediment at the Hakurei Site, Izena Hole, middle Okinawa Trough indicate that sulphides initially formed as aggregates of framboidal pyrite and matured into colloform and euhedral pyrite, which were replaced by chalcopyrite, sphalerite and galena. The initial framboidal pyrite is closely associated with altered material derived from pumice, and alternating layers of pumiceous and hemipelagic sediments functioned as a factory of sulphide mineralisation. We infer that anhydrite-rich layers within the hemipelagic sediment forced hydrothermal fluids to flow laterally, controlling precipitation of a sulphide body extending hundreds of meters..
4. Susumu Umino, Gregory F. Moore, Brian Boston, Rosalind Coggon, Laura Crispini, Steven D{ extquotesingle}Hondt, Michael O. Garcia, Takeshi Hanyu, Frieder Klein, Nobukazu Seama, Damon A. H. Teagle, Masako Tominaga, Mikiya Yamashita, Michelle Harris, Benoit Ildefonse, Ikuo Katayama, Yuki Kusano, Yohey Suzuki, Elizabeth Trembath-Reichert, Yasuhiro Yamada, Natsue Abe, Nan Xiao, Fumio Inagaki, Workshop report: Exploring deep oceanic crust off Hawai`i, Scientific Drilling, 10.5194/sd-29-69-2021, 29, 69-82, 2021.04, Abstract. For more than half a century, exploring a complete sequence of the oceanic
crust from the seafloor through the Mohorovičić discontinuity (Moho)
and into the uppermost mantle has been one of the most challenging missions
of scientific ocean drilling. Such a scientific and technological
achievement would provide humankind with profound insights into the largest
realm of our planet and expand our fundamental understanding of Earth's deep
interior and its geodynamic behavior. The formation of new oceanic crust at
mid-ocean ridges and its subsequent aging over millions of years, leading to
subduction, arc volcanism, and recycling of some components into the mantle,
comprise the dominant geological cycle of matter and energy on Earth.
Although previous scientific ocean drilling has cored some drill holes into
old (> 110 Ma) and young (< 20 Ma) ocean crust, our
sampling remains relatively shallow (< 2 km into intact crust) and
unrepresentative of average oceanic crust. To date, no hole penetrates more
than 100 m into intact average-aged oceanic crust that records the long-term
history of seawater–basalt exchange (60 to 90 Myr). In addition,
the nature, extent, and evolution of the deep subseafloor biosphere within
oceanic crust remains poorly unknown. To address these fundamentally
significant scientific issues, an international workshop “Exploring Deep
Oceanic Crust off Hawai`i” brought together 106 scientists and engineers
from 16 countries that represented the entire spectrum of disciplines, including
petrologists, geophysicists, geochemists, microbiologists, geodynamic
modelers, and drilling/logging engineers. The aim of the workshop was to
develop a full International Ocean Discovery Program (IODP) proposal to
drill a 2.5 km deep hole into
oceanic crust on the North Arch off Hawai`i with the drilling research vessel Chikyu. This drill hole would provide
samples down to cumulate gabbros of mature (∼ 80 Ma) oceanic
crust formed at a half spreading rate of ∼ 3.5 cm a−1. A Moho
reflection has been observed at ∼ 5.5 km below the seafloor at
this site, and the workshop concluded that the proposed 2.5 km deep
scientific drilling on the North Arch off Hawai`i would provide an essential
“pilot hole” to inform the design of future mantle drilling.
5. Verena B. Heuer, Fumio Inagaki, Yuki Morono, Yusuke Kubo, Arthur J. Spivack, Bernhard Viehweger, Tina Treude, Felix Beulig, Florence Schubotz, Satoshi Tonai, Stephen A. Bowden, Margaret Cramm, Susann Henkel, Takehiro Hirose, Kira Homola, Tatsuhiko Hoshino, Akira Ijiri, Hiroyuki Imachi, Nana Kamiya, Masanori Kaneko, Lorenzo Lagostina, Hayley Manners, Harry-Luke McClell, Kyle Metcalfe, Natsumi Okutsu, Donald Pan, Maija J. Raudsepp, Justine Sauvage, Man-Yin Tsang, David T. Wang, Emily Whitaker, Yuzuru Yamamoto, Kiho Yang, Lena Maeda, Rishi R. Adhikari, Clemens Glombitza, Yohei Hamada, Jens Kallmeyer, Jenny Wendt, Lars Wörmer, Yasuhiro Yamada, Masataka Kinoshita, Kai-Uwe Hinrichs, Temperature limits to deep subseafloor life in the Nankai Trough subduction zone, Science, 10.1126/science.abd7934, 370, 6521, 1230-1234, 2020.12, Microorganisms in marine subsurface sediments substantially contribute to global biomass. Sediments warmer than 40°C account for roughly half the marine sediment volume, but the processes mediated by microbial populations in these hard-to-access environments are poorly understood. We investigated microbial life in up to 1.2-kilometer-deep and up to 120°C hot sediments in the Nankai Trough subduction zone. Above 45°C, concentrations of vegetative cells drop two orders of magnitude and endospores become more than 6000 times more abundant than vegetative cells. Methane is biologically produced and oxidized until sediments reach 80° to 85°C. In 100° to 120°C sediments, isotopic evidence and increased cell concentrations demonstrate the activity of acetate-degrading hyperthermophiles. Above 45°C, populated zones alternate with zones up to 192 meters thick where microbes were undetectable..
6. G{'{e } }rard Lods, Delphine Roubinet, Jürg M. Matter, Richard Leprovost, Philippe Gouze, Groundwater flow characterization of an ophiolitic hard-rock aquifer from cross-borehole multi-level hydraulic experiments, Journal of Hydrology, 10.1016/j.jhydrol.2020.125152, 589, 125152-125152, 2020.10.
7. Cocomazzi, Grieco, Tartarotti, Bussolesi, Zaccarini, Crispini, Science Team, The Formation of Dunite Channels within Harzburgite in the Wadi Tayin Massif, Oman Ophiolite: Insights from Compositional Variability of Cr-Spinel and Olivine in Holes BA1B and BA3A, Oman Drilling Project, Minerals, 10.3390/min10020167, 10, 2, 167-167, 2020.02, Holes BA1B and BA3A were drilled into the Wadi Tayin Massif, southern ophiolite complex of Oman, a fragment of the Tethyan oceanic lithosphere obducted onto the Arabian continent. Within the sequence, we have studied a portion of the shallow mantle, composed mainly of strongly serpentinised harzburgite that embeds dunitic levels, the biggest being over 150 m thick. The formation of thick dunitic channels, already approached via published structural and mathematical models, is here investigated with a mineral chemistry approach. We focused on Cr-spinel, the only widespread phase preserved during serpentinization, whose TiO2 content displays a wide variability from low in harzburgite, (TiO2 < 0.25 wt. %), typical of non-metasomatised ophiolite mantle, to moderately high in dunite (TiO2 < 1.10 wt. %) characterizing a rock/melt interactions. The high variability of TiO2, accompanied by similar patterns of Cr# and Mg# is observed, in a fractal pattern, at all scales of investigation, from the whole channel scale to the single thin section, where it affects even single grain zonings. Our results suggest that the over 150 m thick dunite channel here investigated was formed by coalescence of different scale melt channels and reaction zones with different sizes, confirming the published structural model..
8. Yuki Ota, Hodaka Kawahata, Junichiro Kuroda, Asuka Yamaguchi, Atsushi Suzuki, Daisuke Araoka, Ayako Abe‐Ouchi, Yasuhiro Yamada, Akira Ijiri, Toshiya Kanamatsu, Masataka Kinoshita, Kyaw Thu Moe, Weiren Lin, Saneatsu Saito, Yoshinori Sanada, Yohei Hamada, Yasuyuki Nakamura, Yuichi Shinmoto, Hung Yu Wu, Naokazu Ahagon, Kan Aoike, Koichi Iijima, Hideaki Machiyama, Maria Luisa Tejada, Keita Umetsu, Yoichi Usui, Yuzuru Yamamoto, Shuro Yoshikawa, Francisco Jimenez‐Espejo, Satoru Haraguchi, Nobuharu Komai, Hisami Suga, Natsue Abe, Lallan Gupta, Takehiro Hirose, Yuka Masaki, Shun Nomura, Takamitsu Sugihara, Wataru Tanikawa, Yusuke Kubo, Lena Maeda, Sean Toczko, Indian Monsoonal Variations During the Past 80 Kyr Recorded in NGHP‐02 Hole 19B, Western Bay of Bengal: Implications From Chemical and Mineral Properties, Geochemistry, Geophysics, Geosystems, 10.1029/2018gc007772, 20, 1, 148-165, 2019.01, Detailed reconstruction of Indian summer monsoons is necessary to better understand the late Quaternary climate history of the Bay of Bengal and Indian peninsula. We established a chronostratigraphy for a sediment core from Hole 19B in the western Bay of Bengal, extending to approximately 80 kyr BP and examined major and trace element compositions and clay mineral components of the sediments. Higher delta O-18 values, lower TiO2 contents, and weaker weathering in the sediment source area during marine isotope stages (MIS) 2 and 4 compared to MIS 1, 3, and 5 are explained by increased Indian summer monsoonal precipitation and river discharge around the western Bay of Bengal. Clay mineral and chemical components indicate a felsic sediment source, suggesting the Precambrian gneissic complex of the eastern Indian peninsula as the dominant sediment source at this site since 80 kyr. Trace element ratios (Cr/Th, Th/Sc, Th/Co, La/Cr, and Eu/Eu*) indicate increased sediment contributions from mafic rocks during MIS 2 and 4. We interpret these results as reflecting the changing influences of the eastern and western branches of the Indian summer monsoon and a greater decrease in rainfall in the eastern and northeastern parts of the Indian peninsula than in the western part during MIS 2 and 4..
9. Submarine slides and marine geohazards: the study results so far and current problems.
10. F. Inagaki, K.- U. Hinrichs, Y. Kubo, M. W. Bowles, V. B. Heuer, W.- L. Hong, T. Hoshino, A. Ijiri, H. Imachi, M. Ito, M. Kaneko, M. A. Lever, Y.- S. Lin, B. A. Methe, S. Morita, Y. Morono, W. Tanikawa, M. Bihan, S. A. Bowden, M. Elvert, C. Glombitza, D. Gross, G. J. Harrington, T. Hori, K. Li, D. Limmer, C.- H. Liu, M. Murayama, N. Ohkouchi, S. Ono, Y.- S. Park, S. C. Phillips, X. Prieto-Mollar, M. Purkey, N. Riedinger, Y. Sanada, J. Sauvage, G. Snyder, R. Susilawati, Y. Takano, E. Tasumi, T. Terada, H. Tomaru, E. Trembath-Reichert, D. T. Wang, Y. Yamada, Exploring deep microbial life in coal-bearing sediment down to  2.5 km below the ocean floor, Science, 10.1126/science.aaa6882, 349, 6246, 420-424, 2015.07, Microbial life inhabits deeply buried marine sediments, but the extent of this vast ecosystem remains poorly constrained. Here we provide evidence for the existence of microbial communities in similar to 40 degrees to 60 degrees C sediment associated with lignite coal beds at similar to 1.5 to 2.5 km below the seafloor in the Pacific Ocean off Japan. Microbial methanogenesis was indicated by the isotopic compositions of methane and carbon dioxide, biomarkers, cultivation data, and gas compositions. Concentrations of indigenous microbial cells below 1.5 km ranged from <10 to similar to 10(4) cells cm(-3). Peak concentrations occurred in lignite layers, where communities differed markedly from shallower subseafloor communities and instead resembled organotrophic communities in forest soils. This suggests that terrigenous sediments retain indigenous community members tens of millions of years after burial in the seabed..
11. Kazuya Ishitsuka, Takeshi Tsuji, Yasuhiro Yamada, Toshifumi Matsuoka, RECENT SURFACE DISPLACEMENT IN BANGKOK, THAILAND INFERRED FROM PERSISTENT SCATTERER SAR INTERFEROMETRY, 2013 IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM (IGARSS), 10.1109/IGARSS.2013.6723672, 3853-3856, 2013.07, In order to estimate recent surface displacement in Bangkok, we applied persistent SAR interferometry using ALOS/PALSAR images acquired October 2007 to December 2010. Previously, land subsidence due to excessive ground water pumping has been reported in this region. However, we detected that ground surface has rebounded during 3 years of the observation period. This rebounded surface can be interpreted as the response on the ground water recovery to confined aquifer due to the decrease in ground water usage. Since the rebounded areas correspond to past ground subsidence areas inferred from differential SAR interferometry using JERS-1/SAR images, it can be inferred that ground water recovery has especially occurred at the preceding subsidence areas..
12. Development of slope failures at thrust fault scarps in analogue models: application to submarine landslides.
13. Yamada, Yasuhiro, Oshima, Yusuke, Matsuoka, Toshifumi, Yamada, Y, Kawamura, K, Ikehara, K, Ogawa, Y, Urgeles, R, Mosher, D, Chaytor, J, Strasser, M, Slope Failures in Analogue Models of Accretionary Wedges, Submarine Mass Movements and Their Consequences, 10.1007/978-94-007-2162-3_31, 31, 343-353, 2012.01, Sandbox models commonly produce slope failures and mass-transport on the top free surface, which can be an analogue for submarine slides. We have been conducting shortening experiments to model accretionary wedges at subduction margins under several basement configurations of the subducting plate. Slope failures periodically occur when thrust faults reach the top surface of the models. These failures are triggered by steepening of slopes related to the displacement along the underlying thrusts. Internal stress field and physical property of materials may have little impact on the pattern and geometry of failures. Experiments with a topographic relief (e.g., horst) in the basement produce irregular distribution in time of thrusting. Long-lived thrusts, generally initiate at the foot of topographic highs, tend to form longer slopes with thick piles of failed sediments in the footwall. These suggest that anomalous amount of failed sediments in accretionary wedge regions can be used to assume topographic relief in the basement that affected the geometry of detachment. When subducted, such detachment geometries may not be easy to recognize with geophysical technique..
14. Yamada, Yasuhiro, Kawamura, Kiichiro, Ikehara, Ken, Ogawa, Yujiro, Urgeles, Roger, Mosher, David, Chaytor, Jason, Strasser, Michael, Yamada, Y, Kawamura, K, Ikehara, K, Ogawa, Y, Urgeles, R, Mosher, D, Chaytor, J, Strasser, M, Submarine Mass Movements and Their Consequences, Submarine Mass Movements and Their Consequences, 10.1007/978-94-007-2162-3_1, 31, 1-12, 2012.01.
15. Yamamoto, Yuzuru, Yamada, Yasuhiro, Yamashita, Yoshihiko, Chiyonobu, Shun, Shibata, Tadahiro, Hojo, Megumi, Yamada, Y, Kawamura, K, Ikehara, K, Ogawa, Y, Urgeles, R, Mosher, D, Chaytor, J, Strasser, M, Systematic Development of Submarine Slope Failures at Subduction Margins: Fossil Record of Accretion-Related Slope Failure in the Miocene Hota Accretionary Complex, Central Japan, Submarine Mass Movements and Their Consequences, 10.1007/978-94-007-2162-3_32, 31, 355-364, 2012.01, A comparative study of fossil sliding masses and the results of analog experiments indicates the systematic accumulation of submarine sliding masses at subduction margins. An analysis of sliding masses in the Middle Miocene Hota accretionary complex, Central Japan, combined with the results of analog experiments that simulated an accretionary wedge, revealed two types of slope failures at the toe of the accretionary wedge or at the head of an out-of-sequence thrust: relatively small but frequently developed failures on the lower parts of the slope (Type I failures), and relatively large but less frequent failures that affect the entire slope (Type II failures). The Type I slides are precursors of the larger Type II failures. These successive failure processes are recorded in the Hota accretionary complex as the following depositional sequence: three thin conglomerate layers containing small clasts (type I failure deposits) are overlain by a thick slope-failure deposit containing larger clasts (type II). In such an environment, carbonate-cemented and brecciated sandstones, which contain web structures, generally form at depth and behave as competent layers during failure. Clasts of such sandstones are indicative of large slope failures and are found only in type II failure deposits. Type II failures affect the sediment to a depth of similar to 2-10 m, whereas type I failures are surficial (<1 m depth), as inferred from the results of analog experiments and field observations. This systematic pattern of slope failure is important in terms of understanding the formation mechanism of submarine slope failures and in predicting such failures..
16. Numerical modeling of stress change related to fault activities in an accretionary wedge.
17. Experimental research of plagioclase (rock)-gas-water interaction at hydrothermal conditions for CO2 mineralization
Experiments on CO2-water-rock interaction at hydrothermal conditions have been performed to investigate mineral dissolution and precipitatior phenomena, mainly focusing on calcite deposition from the alteration of plagioclase and rocks during CO2 sequestration into geothermal fields. Plagioclase from Shiga and granodiorite from the Ogachi hot/dry rock field (7 g
grain size is 0.5 to 2 mm) were independently enclosed with Kyoto tap water in a Teflon reaction container. The container is filled with CO2 (10 MPa) or N2 gas after evacuating and heated up to 150 °C in an electric furnace with rotation (1 rpm). After 1 to 15 days, the solutions were analyzed for their chemical compositions after filtration and the mineral surfaces were observed by using SEM-EDS. The concentration of Ca in the solutions reacted with CO2 quickly increases within 1 day and is + ∼50 mg/L higher than those without CO2 (with N2 gas). The saturation index shows that the solutions with CO2 are saturated with respect to carbonate such as calcite and aragonite during the reaction. Newly formed calcium carbonate (possibly calcite) was detected by SEM-EDS observation on the plagioclase surfaces, but the other minerals such as kaolinite were not. These results indicate that Ca can be released from rocks (silicates) easily and might be removed as CaCO3 during CO2 sequestration into relatively high temperature (geothermal) fields. Also, Ca-rich plagioclase has a high potential of CO2 fixation as carbonate..
18. Estimation of gas hydrate saturation with temperature calculated from hydrate threshold at C0002 during IODP NanTroSEIZE Stage 1 expeditions in the Nankai Trough.
19. Estimation of strain accumulation around the Kumano Mega-Splay during IODP NanTroSEIZE Stage 1 expeditions in the Nankai Trough.
20. Yamada Yasuhiro, Yamashita Yoshihiko, Yamamoto Yuzuru, Matsuoka Toshifumi, Submarine Landslides at Submarine Margins: Insights from Physical Models, Bollettino di Geofisica teorica ed applicata, 49, 198-203, 2008.07.
21. Kinoshita, M., Tobin, H., Thu, M.K., Gaillot, P., Bourlange, S., Chang, C., Conin, M., Gulick, S., Rodriguez, M.J.J., Martin, K.M., McNeill, L., Miyakawa, A., Moore, J.C., Nakamura, Y., Saito, S., Sawyer, D.S., Tudge, J., Yamada, Y., NanTroSEIZE stage IA: NanTroSEIZE LWD transect, Integrated Ocean Drilling Program: Preliminary Reports, 10.2204/, 314, 1-63, 2008.03, Integrated Ocean Drilling Program (IODP) Expedition 314 was a milestone, both as the inaugural scientific drilling mission of the new vessel, Chikyu, and as the first step in the multistage Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE), an ambitious, coordinated, multiplatform, and multiexpedition drilling project designed to investigate fault mechanics and seismogenesis along subduction mega-thrusts through direct sampling, in situ measurements, and long-term monitoring. During Expedition 314, our primary goals were to obtain a comprehensive suite of geophysical logs and other downhole measurements at sites along a transect from the incoming plate to the Kumano forearc basin using state-of-the-art logging-while-drilling (LWD) technology. Drilling and logging was successfully completed at four sites, ranging in depth below the seafloor from 400 to 1400 m, with partial success at a fifth site. These sites included the frontal thrust and toe region of the outer accretionary prism near the trench, the fault zone and associated thrust sheet of a major out-of-sequence thrust system (the "megasplay" fault), 1 km thick forearc basin deposits, and highly deformed rocks of the interior of the accretionary prism. The principal goals of the LWD program were to document in situ physical properties
stratigraphie and structural features
sonic to seismic scale velocity data for core-log-seismic integration
and stress, pore pressure, and hydrological parameters through both scalar and imaging log measurements. All four sites are slated for continuous core sampling during subsequent IODP NanTroSEIZE expeditions. Depth objectives for this expedition ranged from ∼400 to 1400 meters below seafloor. Logging included the measurement of natural gamma radiation, azimuthal gamma ray density, neutron porosity, full waveform sonic velocity, azimuthal resistivity imaging, zero-offset vertical seismic profile, ultrasonic caliper, and annular fluid pressure, though not all logs in this suite were collected at all sites. Principal results of Expedition 314 include the following: 1. The megasplay thrust sheet is composed of highly deformed and fractured rocks that are anomalously well indurated relative to their present depth. 2. Present-day stress varies markedly along the NanTroSEIZE transect, and stresses in the upper 1.4 km are strongly compressional in the outer, active accretionary prism but extensional in the forearc basin. 3. The occurrence of gas hydrate as a cement preferentially located in sandy portions of turbidite beds above a bottom-simulating reflector was quantified. 4. Drilling at Sites C0001 and C0002 also provides important pilot hole information that will help prepare for the planned deep-riser sites for later stages of NanTroSEIZE drilling..
22. Study of interaction between wedge deformation and friction change in decollemant zone by Distinct Element simulations.
23. Estimation of permeability structure in an accretionary wedge by useing numerical simulation..
24. Numerical simulation to estimate the influence of structural deformation to fluid flow in a modeled accretionary wedge.
25. Onishi, K., Ishikawa, Y., Yamada, Y., Matsuoka, T., Measuring electric resistivity of rock specimens injected with gas, liquid and supercritical CO2, SEG Technical Program Expanded Abstracts, 10.1190/1.2369800, 25, 1, 1480-1484, 2006.09, CO2 sequestration in a deep aquifer is considered one of the most effective method to solve Global warming. We must understand the behavior of injected CO2 to confirm long-term stability and economic efficiency of CO2 sequestration. We tried to monitor the behavior of gas, liquid and supercritical CO2 injected into water-saturated sandstone by measuring the resistivity of rock specimens. CO2 of gas, liquid, and supercritical phases was flushed through the sandstone specimens at three different flow rates. We could monitor the time-lapse behavior of CO2 in water-saturated sandstones. Also, we tried to convert the resistivity data to the CO2 saturation using Archie's equation. The saturations estimated from resistivity becomes nearly equal to the values calculated from actual outflow volumes. This result indicates the high reliability of electric exploration to monitor CO2 saturation. © 2005 Society of Exploration Geophysicists..
26. Yasuhiro Yamada, Hitoshi Okamura, Yoshihiko Tamura, Futoshi Tsuneyama, Analog models of faults associated with salt doming and wrenching: Application to offshore United Arab Emirates, AAPG Memoir, 10.1306/1033718M852969, 85, 95-106, 2005.06, Regional stress has a significant impact on fault development during the formation of salt dome structures. To examine such effects of wrenching, we conducted a series of analog experiments of updoming using dry, granular materials and observed the deformation on the top free surface. The experiments included three deformation styles: (1) updoming followed by wrenching, (2) simultaneous updoming and wrenching, and (3) wrenching followed by updoming. In the first series of the experiments, the faults produced by simple updoming were overprinted by two strikeslip fault systems that were generated by the subsequent wrenching. The second series of experiments with the configuration of simultaneous updoming and wrenching generated normal faults in a direction perpendicular to relative extension by the wrench. In the third series of experiments, the Riedel and anti-Riedel shear faults formed by wrenching were deformed by the subsequent updoming and were overprinted by the faults related to the updoming. These experimental results are applied to the fault systems observed above dome structures in the United Arab Emirates region, where extensive faults in the northwest-southeast direction have developed. By analogy, these faults were probably formed during an updoming and simultaneous wrenching. The direction of simple shear inferred from a comparison of real faults and experimental results suggests that dextral wrenching caused by the Oman stress regime during the Late Cretaceous affected the region at the time of the updoming. Copyright © 2005 by The American Association of Petroleum Geologists..
27. Matsuoka, T., Hasegawa, T., Yamada, Y., Tamagawa, T., Ashida, Y., Computer simulation for sandbox experiments, SEG Technical Program Expanded Abstracts, 10.1190/1.1816301, 20, 1, 1187-1190, 2001.09, Structural deformation (e.g. folds and faults) of geological strata has been analyzed by analog modeling techniques for nearly a century. Recent knowledge suggests that sandbox experiment is the most appropriate to model brittle behavior of the upper crust. This type of physical experiments using granular materials can also be done as numerical simulation (digital modeling) on the computer with the Discrete Element Method (DEM). Two types of geological settings, the extension case and the contraction case, are investigated and compared with the sandbox experiments results. It is concluded that the DEM approach to the geological deformation study can be a powerful tool to simulate fault related structures..
28. Yamada, Y., McClay, K., Hangingwall deformation above inverted 3D listric fault systems - Insights from experiments and section-balancing techniques, SEG Technical Program Expanded Abstracts, 10.1190/1.1816712, 20, 1, 655-658, 2001.09, Fault geometry is a primary control on hangingwall deformation. In this study, a series of inversion analogue experiments was conducted by using rigid fault surfaces of spoon-like true 3D geometries. The hangingwall geometry on serial sections of the experiments was then examined with conventional 2D geometric models. The deformation geometry of the hangingwall has an along-strike variation corresponding to the 3D geometry of the underlying detachment. The apparent shear plane inclination and the estimated shortening also show a systematic change along strike. These changes suggest that the hangingwall displacement had an along-strike element during deformation
the hangingwall material moves from the regions above salients to those above embayments in the detachment surface during contraction. The data presented in this paper help us understand 3D geometric relations between the hangingwall deformation and the underlying detachment surfaces..