


Dec.4 　　Room No.1 (Gallery 1, 4F)

Session	[CO2][Resource Exploration1]
Chair	Tetsuo No (JAMSTEC)

Dec.4	10:20 - 10:40 "This study addresses the growing concern over geomechanics associated with CO2 geological storage (CCS) for carbon neutrality. Several operational CCS projects worldwide have reported surface deformation. Extracting subsurface pressure and stress changes from InSAR-observed surface displacement would significantly benefit geomechanical assessment of CO2 injection. This requires constructing a geomechanical model from the surface to the underburden formation. However, data acquisition in oil and gas development has historically focused on reservoir intervals. To address the lack of data for shallow formations and overburden layers, we investigated the relationship between depth and porosity, and used this to estimate elastic constants via a rock physics model. We utilized the Hertz-Mindlin model, uncemented sand model, and constant-cement model to characterize elastic wave velocity distributions, considering mechanical compaction and cementation effects. This provides guidance for future geomechanical model construction. We also demonstrated the effectiveness of reducing uncertainty in overburden mechanical properties for estimating subsurface stress states from surface deformation using coupled geomechanical modeling"	1) Rock physics-based 1D geomechanical modeling from surface to depth for investigating ground deformation during CO2 injection
		*Koji Kashihara・Hidehiko Shimizu(1) 1:JAPEX
Dec.4	10:40 - 11:00 "In the development of carbon-neutral projects, such as CCS-CCUS, the construction of accurate subsurface digital twins is an intrinsically important issue from the perspective of understanding and predicting the time history of subsurface fluid flow and verifying it with monitoring data. In this study, we present the basic concept and workflow for constructing subsurface structure-property models by extracting various wavefield information, using domestic multi-scale, multi-mode seismic data and related synthetic waveform data as case studies."	2) Integrated analysis of various wavefield information to improve the accuracy of subsurface models
		*Susumu Abe・Masafumi Kato・Kimiaki Ochi・Keisuke Teranishi(1)・Hidehiko Shimizu(2)・Hiroshi Sato・Tatsuya Ishiyama(3) 1:JGI,Inc,2:JAPEX,3:Univ. of Tokyo
Dec.4	11:00 - 11:20 "Monitoring injected CO2 within its reservoir is essential for predicting the risk of leakage, enhancing storage efficiency, lowering costs, and minimizing the risk of induced seismic activity.	3) Real-Time Monitoring System for Offshore CO2 Storage Sites
		*Takeshi Tsuji・Tarek Imam・Ahmad Ahmad・Kazutoshi Sakamoto・Arata Kioka(1)・Masaharu Ueki・Tadashi Ito(2)・Yuichi Machijima・Yuuma Ebihara(3) 1:U. Tokyo,2:UETAX,3:LAZOC
Dec.4	11:20 - 11:40 "A large-scale CCS project has been carried out at Sleipner in the North Sea, and a 4D geological model and detailed physical property distribution based on 4D seismic reflection surveys acquired before and after CO2 injection have been made publicly available. Using this 4D geological model, we will demonstrate the effectiveness of the integrated exploration of muography and seismic waves on a real field scale. Although more statistics are needed, these preliminary results, based on comparisons of muon counts, standard deviations, and energy spectra, suggest promise. This indicates the potential to distinguish between different saturation levels using cosmic-ray muons. To further reduce computation time, we propose using codes such as MUSIC and EcoMug, implementing a staged simulation process to significantly shorten the overall computation time while maintaining accuracy."	4) Coupled exploration of muography and seismic waves using 4D geological model of Sleipner CCS project
		*Jun Matsushima・Hamid Basiri(1)・Masashi Kodama・Toshiyuki Yokota(2)・Mohammed Ali・Fateh Bouchaala・Ahmed Eleslambouly(3)・Hiroyuki K.M. Tanaka(4) 1:Univ. of Tokyo, GSFS,2:AIST, GSJ,3:Khalifa University,4:Univ. of Tokyo, ERI
Dec.4	11:40 - 12:00 "Reservoir monitoring is essential for the successful implementation of CCS（Carbon Capture and Storage）/CCUS（Carbon Capture, Utilization and Storage）, In this presentation, we will begin by reviewing the development history of the Portable Active Seismic Source (PASS) and the innovative design of PASS-M1, leading to a sufficient depth of investigation for CCS. We will share our findings that vibrations from PASS reached a depth of 2,200 meters, as recorded through optical fiber cables installed in the experimental wells at the Minami-Aga Field of INPEX. This demonstrates the potential of PASS as a highly effective tool for CCS monitoring."	5) PASS Signal Reaching a Depth of 2,200 Meters: Towards Continuous Monitoring for CCS
		*Akihisa Takahashi(1)・Takeshi Tsuji(2)・Junji Kinoshita(3)・Takashi Hamajima(1)・Shotaro Nakayama(4)・Takuji Mouri(5) 1:Wavelet, Inc.,2:The University of Tokyo,3:Kyushu University,4:INPEX,5:JOGMEC


Session	[Resource Exploration2][Metal]
Chair	Atsushi Suzuki (JX Metals Resources Exploration ＆ Development Co., Ltd.)

Dec.4	13:30 - 13:50 "In this paper we introduce an effective and practical method to evaluate the induced polarization (IP) effect, caused by the seafloor hydrothermal deposits, by using seabed transient electromagnetic (TEM) survey data. The apparent conductivity and its time derivatives calculated from TEM data can be used to detect the IP effect by comparing with TEM forward modeling results. We have applied this method to the TEM data acquired over the area including hydrothermal deposits, and the results show that our method can qualitatively evaluate the IP effect with lower computational costs."	6) Effective and practical interpretation of marine transient EM data (1)
		*Keiko Nakayama(1)・Masashi Endo(2)・Akira Saito(3) 1:GeoBless Co., Ltd.,2:RedStoneGEO, LLC,3:Waseda Univ.
Dec.4	13:50 - 14:10 "Effective and practical technique for the quantitative interpretation of marine transient electromagnetic data for the exploration of sea-bottom mineral ore deposits is demonstrated. Because the acquired data may be distorted by the strong induced polarization effect, not only the conductivity but also the IP effect need to be solved. The results show that more reliable sea-bottom mineral ore deposits can be quantitatively evaluated by the interpretation techniques for the limited practical data."	7) Effective and practical interpretation of marine transient EM data (2): Quantitative interpretation
		*Masashi Endo(1)・Keiko Nakayama(2)・Akira Saito(3) 1:RedStoneGEO,2:GeoBless,3:Waseda Univ.
Dec.4	14:10 - 14:30 "Sulfide minerals are often confirmed in seafloor hydrothermal fields. However, the lateral and vertical extent of these sulfide mineral deposits remains unknown based on the camera observations. Since the massive sulfide exhibits low resistivity, electrical resistivity surveys is a powerful tool for delineating the subseafloor distribution of the sulfide minerals. We conducted a direct current (DC) resistivity survey with a vertical electrode array (i.e., the marine vertical DC resistivity survey system) in the hydrothermal vent area off the Aogashima island, one of the Ogasawara Islands, where the sulfide minerals with high gold content have been found on the seafloor. The vertical cable suspended from a remotely operated vehicle incorporates an electrode array, enabling the near-seafloor exploration even with rough topography. This system also allows the simultaneous measurement of self-potential field together with the seafloor video images. Based on the measured apparent resistivities, the subseafloor resistivity structure was obtained by a two-dimensional inversion scheme. In the inversion result, a low resistive zone with the horizontal extent of about 100 m and with the thickness of about 20 m was revealed. We suggest that this low resistive zone possibly reflects the buried sulfide mineral deposits below the seafloor."	8) Resistivity structure inferred from a marine vertical DC resistivity survey system in the Aogashima hydrothermal region
		*Ryoichi Kitatani・Keiichi Isizu・Tada-nori Goto(1)・Hisanori Iwamoto(2)・Takahumi Kasaya(3) 1:University of Hyogo,2:NME,3:JAMSTEC
Dec.4	14:30 - 14:50 "Seafloor massive sulfide deposits are attracting attention as new sources of industrially important metals. Methods for detecting these deposits using a multi-beam echo sounder (MBES) was previously demonstrated, with recent interest in automating this detection using object detection models. However, conventional models often produce numerous false positives due to the sparse occurrence of hydrothermal signals during actual explorations. Hence, we incorporated a simple time-series analysis into the outputs of conventional object detection models. An object detection model YOLOv8 was utilized to detect hydrothermal signals from time-series MBES data obtained by autonomous underwater vehicles (AUVs). A 5-term moving average was applied to the confidence scores, followed by binary classification to determine the presence of hydrothermal signals in each frame. Cross-validation using data from 13 dives showed an improvement in precision from 0.425 to 0.582 at the frame level and from 0.142 to 0.541 at the hydrothermal event level. Additionally, an evaluation method considering practical aspects of hydrothermal exploration, such as deployment frequency and discovery rates, was developed. This method more accurately assesses the practical utility of hydrothermal exploration. The results indicate that the proposed algorithm, leveraging time-series information through a moving average, is potentially effective for practical hydrothermal exploration."	9) Developing a new and precise method to detect seafloor hydrothermal activities from AUV MBES images
		*Takayuki Genda(1)・Kazuhide Mimura(2)・Kentaro Nakamura(1)・Takeshi Nakatani・Kazuya Kitada(3)・Kazutaka Yasukawa・Yasuhiro Kato(1) 1:Univ. of Tokyo,2:AIST,3:JAMSTEC
Dec.4	14:50 - 15:10 "The marine vertical DC resistivity survey system developed by JAMSTEC can simultaneously detect self-potential anomaly area using vertical electric fields and resistivity structure. This system also has HD camera system and CTD sensor, and enabling highly efficient exploration for hydrothermal deposits. In this presentation, we will overview the improved vertical DC resistivity survey system, and a new operation method for survey vessel of a private company will be introduced. As the results of test observation cruises, we obtained the consistency results with the existing results."	10) Application of a marine vertical DC resistivity survey system
		*Takafumi Kasaya(1)・Hisanori Iwamoto(2) 1:JAMSTEC,2:NME


Dec.4 　　Room 2 (Main Conference Room, 4F)

Session	[Civil Engineering1][Disaster Prevention1][Earthquake1]
Chair	Keiko Nakayama (GeoBless Co., Ltd.)

Dec.4	10:20 - 10:40 "In regions where buildings and houses were severely damaged during the 2024 Noto Peninsula Earthquake, microtremor measurements were conducted at strong motion seismograph sites and heavily damaged areas. Examples of the measurement results are demonstrated. In Kawai-machi, Wajima City, microtremor measurement and visual damage inspection along a 250 m long EW line through the seismometer K-NET Wajima (ISK003) were carried out. They revealed the contrast of damage and that slight damage or no damage to houses on the foothills where ISK003 is located, on the contrary collapse and very heavy damage to houses in the city center side on the flat ground. Moreover, spatial distributions of both the heavy damage ratio and predominant period of the ground are harmonized."	27) Characteristics of Microtremors at Seismograph Sites and Damaged Sites in the 2024 Noto Peninsula Earthquake
		*Shinichiro Mori(1)・Takumi Hayashida(2) 1:Ehime University,Building Research Institute
Dec.4	10:40 - 11:00 "The advantage of the microtremor survey is that it can obtain the velocity structure directly below the seismometer array. This feature allows the detection of minute velocity structures, such as underground cavities. The survey depth of commercially available microtremor 　survey devices is the same as the deployment length of the seismometer, and devices with a small survey depth do not take advantage of the excellent features of the microtremor survey. Microtremor surveys are used in the design and planning of public works. It is necessary to disclose the conditions for applying microtremor array surveys, the range of velocity structures, and the performance of the survey, such as the survey depth and resolution. In measuring microtremors, a heavy, highly sensitive seismometer is fixed to the ground to avoid the effects of wind and sound and to faithfully record the minute vibrations of the ground. SPAC coefficients were obtained at five points around a circumference in the field in December and May. When the SPAC coefficients for each direction were compiled, there were no identical values, but the circularly averaged SPAC coefficients for December and May were the same. The repeatability of the circularly averaged SPAC coefficients was confirmed."	28) Remarks on the number of observation points and depth of search for the spartial autocorrelatin method(2)
		*Hisao　Hayashi(1)・Toshio Takagi(2)・Tsuyoshi　Haraguchi(3) 1:Geo-X Gonsultants Corp.,2:Fukken co., Ltd.,3:STORY
Dec.4	11:00 - 11:20 "Infrared thermography is close to being put into practical use to detect lifting and peeling of bridge structures, but it is difficult to judge the tunnel lining concrete, where temperature changes are minimal. Several methods have been proposed to artificially heat the lining concrete, but there are problems with how to raise the temperature in a short period of time and with the heating equipment. In this study, we changed heating approach and decided to cool the lining concrete, created test specimens simulating deformation, and examined detection methods and confirmed the detection accuracy of lifting and peeling. In this paper, we report a case study in which the method was applied to deformation in a sheet pile tunnel as a verification test in an actual tunnel."	29) Verification of Detection Method for Floating Tunnel Lining Concrete Using Infrared Thermography
		*Makoto Nakamura・Sota Shimohama・Ryoya Kojima(1) 1:West Nippon Expressway Engineering Kansai
Dec.4	11:20 - 11:40 "We conducted a time-lapse resistivity survey to monitor a real-scale experimental embankment using an artificial rainfall simulator, and successfully monitored the resistivity changes during embankment failure. This paper presents the findings obtained through the monitoring results. The monitoring was conducted twice using different rainfall intensities; one caused the embankment to collapse, and the other did not. Two types of datasets were obtained by the two monitoring experiments. Two distinctions were found between the two datasets. One was that the contact resistance of some electrodes showed a stepped change only when collapse occurred. Second, the resistivity increased at the toe and crown of the embankment only when collapse occurred. These observations suggested the creation of deformation, including changes in porosity and surface cracks, before the collapse. The time-lapse resistivity survey may have the capability to detect early warning signs of a slope collapse."	30) Resistivity monitoring of an embankment using the artificial rainfall simulator
		*Hiroshi Kisanuki・Chisato Konishi・Tsuyoshi Kobayashi・Mitsuru Yabe・Takanori Ishikawa(1)・Naoki Sakai(2)・J.E. Chambers・P.I. Meldrum・P.B.Wilkinson ・O.Kuras(3) 1:OYO,2:NIED,3:BGS
Dec.4	11:40 - 12:00 "GEM2 (Geophex, Ltd.) is a device that can easily perform Slingram electromagnetic exploration. However, it is difficult to measure background noise, and zero adjustment by bias noise removal is unstable, making it difficult to handle the data. Therefore, this paper proposes a new response value setting method. This method assumes that the ground is homogeneous, performs calibration measurements at three heights of 0.5, 1.0, and 1.5 m, calculates the approximate resistivity, and then sets the response value of each frequency based on the resistivity. This stabilizes the correlation between the frequencies of the in-phase and quadrature components, making it possible to perform stable resistivity analysis with fewer errors. Here, we introduce an example of a survey using the response value setting method."	31) Suggestion of phase-response-value setting method for multi-frequency electromagnetic survey system（GEM-2）
		*Naofumi Nakamura(1) 1:NGP


Session	[Civil Engineering2][Disaster Prevention2][Earthquake2]
Chair	Shinichiro Mori (Ehime University)

Dec.4	13:30 - 13:50 A deep marine seismic survey was conducted in the eastern part of the source area of the 2024 Noto Peninsula earthquake (M 7.6) to study the crustal structure related to earthquake source fault. We will reveal characteristics of the crustal structure related to the formation of earthquake source fault based on the seismic profiling and P-wave velocity structures obtained from this seismic survey in the near future.	32) Deep marine seismic survey across the eastern edge of hypocentral region of the 2024 Noto Peninsula earthquake
		*Tetsuo No・Gou Fujie・Yasuyuki Nakamura・Tsutomu Takahashi・Koichiro Obana(1)・Tatsuya Ishiyama(2)・Kenichi Akama(3) 1:JAMSTEC,2:ERI,3:JGI
Dec.4	13:50 - 14:10 "For improving shallow SH reflection method, especially, getting velocity fields with higher accuracy and resolution, we focus on full waveform inversion (FWI) technique, write a time domain FWI program using python’s packages, devito, scipy, etc. and carry out basic numerical experiments to investigate its applicability. The velocity field obtained by velocity analysis in conventional CMP stacking method, is interpolated and used as initial models in the FWI experiments. The results of these experiments show that the reconstructed fields have detailed velocity structures compared to initial models but also many assignments to tackle remain for getting reasonable fields stably. We recognize FWI could be a one technique for improving shallow SH reflection method and would step forward firmly to make this approach become a practical tool."	33) Basic numerical experiments of FWI for improving shallow SH reflection method
		*Takashi Imayoshi・Tetsuya Takemoto(1) 1:Hanshin Consultants
Dec.4	14:10 - 14:30 "Seismic interferometry using microtremors is used for various purposes, such as imaging and monitoring of underground structures. Seismic interferometry assumes an isotropic wave field, but in many cases the actual wave field is not isotropic, and this can cause errors in the analysis results. In this study, we applied the components-coherency-weighted stack (CCWS) method, which selects data whose arrival direction of Rayleigh wave is within the spatial-phase zone (SPZ). We estimated the arrival direction of Rayleigh wave using Hi-net data from 2014 to 2017. We selected segments whose arrival direction was within the SPZ and stacked the cross-correlation function. As a result, the SN ratio was improved by the CCWS method for some station pairs. On the other hand, the results suggest that the effect of the CCWS method may be limited in areas where the correlation coefficient between the phase-shifted radial and vertical components is low. This method is expected to contribute to improving the accuracy of seismic interferometry, especially in environments where the directionality of the waves is strong."	34) Seismic wave interferometry considering the direction of Rayleigh wave by using CCWA method
		*Hiro Nimiya(1) 1:AIST
Dec.4	14:30 - 14:50 "In the center of Morioka City, microtremor surveys were carried out densely using arrays with radii of 0.6m and 10m, and S-wave velocity structure models were estimated up to a depth of 30m. As a result, it was revealed that S wave velocities of a surface layer were high in the center area. 30m average S-wave velocity were calculated, and site ground amplification factors were evaluated. From a comparison of the observed amplification factor with the J-SHIS’s one, and the questionnaire seismic intensity distribution, it was found that no amplification was observed in the center area of Odori district, where a high amplification factor was assumed in the J-SHIS. The site amplification factor obtained from the previous microtremor observations carried out in the northwestern part of Morioka city and the results of the center area were integrated to evaluate the amplification factor distribution in the Morioka city area. From a comparison with the J-SHIS and the questionnaire seismic intensity, both showed high values in the northwestern area of Morioka city, and low values in the center area, so that the site amplification factor and the seismic intensity were consistent."	35) Evaluation of site amplification factors in Morioka area by microtremor array surveys
		Kenshiro Oikawa・*Hidekazu Yamamoto・Tsuyoshi Saito(1) 1:Iwate University
Dec.4	14:50 - 15:10 "The Noto Peninsula earthquake that occurred on January 1, 2024, caused damage to many wooden houses and infrastructure facilities in Wajima City and Shika Town, Ishikawa Prefecture, with a maximum intensity of 7 on the Japanese seismic scale. The authors visited the area several times from late January to late March after the earthquake to investigate the damage and its causes. Here, single-point microtremor observations and microtremor array surveys were conducted mainly in two areas in Nanao City where the damage to two buildings was very different (downtown Nanao and Tazuruhama area). In the single-point observation, the H/V spectral ratio is used for analysis. In the array survey, phase velocity was obtained and the S-wave velocity structure was estimated by inverse analysis. From the single-point microtremors, it was confirmed that the seismic characteristics were different in the two districts. The phase velocity obtained from the array survey also showed significant differences between the two districts. In the future, we plan to investigate the relationship between the site amplification and building damage based on the estimated ground properties."	36) Microtremor array survey in the disaster area of 2024 Noto Peninsula earthquake
		*Tsutomu Ochiai(1)・Yoshiharu Shumuta・Yoshiya Oda(2)・Nobuhiro Hasegawa(3)・Takahisa Enomoto(1) 1:Kanagawa-u.,2:Tokyo Metropolitan Univ.,3:Tokyo Denki Univ.
Dec.4	15:10 - 15:30 "We carried out surface wave methods, and single station three-component (3C) microtremor measurements at Kyoto Basin to delineate three-dimensional (3D) S-wave velocity (Vs) structure. Dispersion curves were obtained by surface wave methods at approximately 25 sites, and horizontal to vertical spectral ratios (H/V) were obtained by single station 3C microtremor measurements at approximately 270 sites. H/V peaks are ranging 0.4~2.0 Hz and 0.2~0.4 Hz in the northern and southern portion of the Basin respectively. We estimated Vs structure based on deep learning. Firstly, we estimated one-dimensional (1D) Vs profiles by the inversion of dispersion curves. Secondly, the first stage deep learning predicted Vs profiles using the 1D Vs profiles estimated in the first step as training data, at the sites where only H/V were observed. Thirdly, we used 1D Vs profiles predicted in the second step as initial profiles and applied non-linear inversion using H/V. Finally, the second stage deep learning predicted Vs profiles with 100 m grid intervals, using the training data consisting of Vs profiles estimated in the third step, coordinate, geomorphological and geological information etc. The resultant 3D model delineated different shallow Vs structures between the north and south of the Basin."	37) Active and passive surface wave methods and single station three-component microtremor measurements at Kyoto Basin
		Koichi Hayashi(1)・Toru Suzuki・Koki Yokozawa・*Kei'ichiro Sakanishi(2)・Tomio Inazaki(3)・kenji Mima(4)・Chisato Konishi・Haruhiko Suzuki(5) 1:Kyoto University,2:Mony Exploration,3:Non-affiliated, 4:Ohta Geo Research,5:OYO Corporation


Dec.4 　　Core Time: Room 1 (Gallery 1, 4F), Exhibition: Room 3 (Gallery 2, 4F)

Session	[#Poster]
Chair	Takeshi Tsuji (The University of Tokyo)

Dec.4	15:50 - 17:50 "Analyzing and utilizing camera movies during shakings by earthquake hold value for understanding seismic ground motion and disaster prevention research. In this study, we tried to analysis in-vihicle camera movies recorded during the 2024 Noto Peninsula Earthquake using object tracking technology to evaluate seismic ground motion and related phenomena captured. As a result, we could qualitatively show the characteristics of seismic motion and the time characteristics of structural damage by plotting time history waveforms and spectra. These results suggest that camera movies during earthquake could be used as a means to understand the spatial characteristics of seismic motion, and it may serve as a complementary tool to strong ground motion observation network."	P-1) Analysis of events due to strong ground motion using camera movies during the 2024 Noto Peninsula Earthquake
		*Kazuma Moriya・Nobuyuki Yamada(1) 1:Kochi Univ.,Kochi Univ.
Dec.4	15:50 - 17:50 "The validity of Distributed Acoustic Sensing (DAS) recordings using optical fibers placed on the ground surface can be evaluated by comparing them with geophone recordings, which are conventional sensors. In this paper, we reconsider the theoretical equation for comparing velocity-type geophone and surface-DAS recordings, and compare actual data and simulation results with two different equations: one based on the three-square theorem to account for strain in directions other than the optical fiber axis, and the other based on the spatial derivative of the horizontal velocity, which has been used conventionally. The results were compared with actual data and simulation results. As a result, it was found that there is no difference between the two equations when the amplitude of waves generated by a Kakeya oscillation is small, but there is a difference when the amplitude is large. In addition, a comparison of strain rates between geophones and S-DAS showed that there was a difference between waves with large and small propagation velocities. When the geophone spacing was closer to the gauge length, no difference was observed between waves with high and low propagation velocities, suggesting that appropriate geophone spacing should be considered when comparing geophone and DAS recordings."	P-2) Theoretical, numerical, and real data comparison of DAS measurements using optical fibers installed on the ground surface and three-component velocity-type geophone recordings
		*Mori Keishiro(1)・Kobayashi Yuki・Naruse Ryohei(2)・Ikeda Tatsunori(1) 1:Kyushu University,2:INPEX
Dec.4	15:50 - 17:50 "Adjoint state method can be used to obtain gradient vector of objective function. We developed a 3D analysis code for MT inversion using this method. We also validated the code using some test models. As a result, we could confirm that the code can analyze MT inversion problems."	P-3) Development of a three-dimensional inversion code for magnetotellurics using adjoint state method
		*Atsushi Suzuki(1) 1:JX Metals Resources Exploration ＆ Development Co., Ltd.
Dec.4	15:50 - 17:50 "Oil and gas reservoirs exhibit high resistivity below the seafloor. Therefore, marine electromagnetic survey methods using controlled source are widely used for their explorations. The accuracy of modeling of the electrical resistivity structure has been evaluated by various methods, focusing on the electromagnetic survey data and its measurement error. However, the dependence of accuracy of estimated resistivity on the water depth in the survey area has not been discussed quantitatively. In this study, we used a Markov chain Monte Carlo (MCMC) method to estimate the error in the accuracy of inferred electrical resistivity. Here, assuming a horizontal layered structure, the received electric field amplitude values synthetized by numerical forward calculations. Determination of both the resistivity structure and its accuracy were evaluated by MCMC method. As a result, we quantitatively evaluated and discussed the degrees of modeling accuracy both in the shallow-water and deep-water areas."	P-4) Evaluation of the accuracy of structural estimation in marine controlled-source electromagnetic survey using Markov chain Monte Carlo methods
		*Naoki Takahashi・Tatsuya Kado ・ Tada-nori Goto(1) 1:Univ. Hyogo
Dec.4	15:50 - 17:50 "Hydrothermal circulation analysis is crucial for geothermal energy resource utilization. However, there are a few examples of the analyses based on the complex subsurface resistivity structure that have actually been obtained by magnetotelluric method. This study aims to simulate numerically around the Unzen hot spring area, Nagasaki Prefecture, Japan, where the detailed three-dimensional resistivity structure is available. At the first attempt, we reproduce a hydrothermal convection model consistent with the resistivity structure of hydrothermal areas through hydrothermal convection simulations. We simplified the subsurface resistivity structure in the Unzen hot spring area, using spatially dense audio-magnetotelluric survey data. The notable feature is the spatial discrepancy between an active fault and fumaroles. In general, the fault plays a role of a conduit for upcoming hydrothermal fluid; however, a number of fumaroles are obvious on the surface only at the southern side of fault, and are not observed at the northern side. The resistivity structure also indicates the difference across the fault, corresponding to the surface hydrothermal activity. For understanding the discrepancy and resistivity features, an open software “HYDROTHERM” was used. We investigated how subsurface structure, especially the hydraulic structure along the fault, influences hydrothermal circulation through various numerical calculations."	P-5) Numerical simulation of hydrothermal circulation based on AMT surveys in the Unzen geothermal area
		*Mao Monden・Nagi Yamashita・Tada-nori Goto(1) 1:Univ. Hyogo
Dec.4	15:50 - 17:50 "Ground penetrating radar (GPR) survey is useful for determination of buried locations of subsurface objects. However, it is difficult for beginners to identify the buried objects from the raw GPR image obtained by the conventional profile measurements (so-called B-scan). It is also difficult to estimate the depth of buried objects without the wide-angle GPR measurements, which is generally used to determine the radio wave velocity below the ground surface. Semblance analysis has been used as a simple method to overcome these problems (e.g., Aoike et al., 2019); it allows the estimation of radio wave velocity and also the depth and location of the target based on the GPR profile measurement alone. A few previous studies adopted the semblance, but the effectiveness has not been quantitatively evaluated. In this study, the synthetic GPR data was prepared by numerical calculations using the FDTD method. Then, the semblance analysis was applied to the synthetic data to verify the effectiveness of semblance. As a result, the buried objects were appropriately and easily detected by using the semblance, and their horizontal positions could also be accurately identified. In a simple model, the depth of buried objects was determined within an accuracy of 10-20%."	P-6) Effectiveness of semblance analysis in identifying locations of buried objects using profile-measurement in GPR
		Shino Nouchi・*Tada-nori Goto(1) 1:Univ. Hyogo
Dec.4	15:50 - 17:50 "Efficient detection of underground cavities and buried objects using ground-penetrating radar (GPR) is critical for ensuring road infrastructure integrity and safety. Traditionally, this process depends on skilled technicians manually interpreting extensive GPR datasets, which is labor-intensive and time-consuming. Recent advances in machine learning (ML), particularly convolutional neural networks (CNN), have been employed to automate detection processes. However, these methods require substantial amounts of labeled training data, which is challenging to collect due to the variability in the shapes and sizes of buried objects and diverse regional noise. In response to these challenges, this study introduces a convolutional autoencoder (CAE) for anomaly detection in GPR data, offering a novel solution that circumvents the need for labeled training data. The CAE method learns and models background noise patterns, enabling the identification of reflection anomalies that may indicate the presence of subsurface features. Initially presented at EAGE 2023, preliminary results demonstrated the method’s effectiveness with limited data. This presentation extends those findings, incorporating more diverse datasets and providing an in-depth analysis of the challenges of detecting anomalies under varying noise conditions."	P-7) An AI Method for Detecting GPR Reflectors with Generative Model
		*Shinichiro Iso(1) 1:Fukada Geological Institute
Dec.4	15:50 - 17:50 "In surface wave exploration, the constrained least-squares method has been used primarily for estimating subsurface S-wave velocity structure by inversion of observed phase velocity data. The sparse estimation method has recently been recognized as an alternative to this method and has been utilized in various fields. Fused lasso, an extension of lasso, which is a representative sparse estimation method, can be used for the inversion of observed phase velocity data in surface wave exploration and has advantages over conventional methods. When the alternating direction method of multipliers (ADMM) is applied to solve the fused lasso, there are two hyperparameters, and different S-wave velocity structure models are obtained depending on these values. In selecting the optimal hyperparameters, i.e., the optimal model, we attempted to apply several information criteria. Several numerical examples are used to compare and discuss the information criteria in selecting the optimal model."	P-8) Inversion of Surface Wave Apparent Phase Velocity Data Using Fused lasso (2) - Model Selection Based on Information Criteria -
		*Shigeki Kawamura(1) 1:unaffiliated
Dec.4	15:50 - 17:50 "We reported a summary of the results of the 2022 survey, which was conducted jointly by the party for Microtremor. The H/V spectra and phase velocity data from this survey are available to the public in https://seisimager.com/. We believe that sharing the observation data will enable a diverse discussion. We will continue to compile a database of the data measured at the party for microtremor and make it available to the public."	P-9) Estimation of S-wave velocity structure of shallow sedimentary layers using microtremor array measurements in Ozu city.
		*Haruhiko Suzuki(1) 1:OYO [Voluntary members of The Party for Microtremor]
Dec.4	15:50 - 17:50 "In previous studies, I have reported the results of small-scale microtremor array observations and S-wave velocity structure estimation along a measuring line of about 2.5 km in length that runs north-south across the Kochi Plain, passing near Kochi Castle. In this presentation, I'll report the results of the survey at a slightly higher elevation point at the edge of the plain, a downtown area in the center of the plain, and a strong-motion observation point, which have not been conducted so far."	P-10) Microtremor exploration at the edge of the Kochi Plain
		*Nobuyuki Yamada(1) 1:Kochi Univ.


Dec.5 　　Room 1 (Gallery 1, 4F)

Session	[Oil & Gas][Resource Exploration3]
Chair	Tadanori Goto (University of Hyogo)

Dec.5	9:30 - 9:50 "Zero-offset VSP data (ZOVSP) is widely used not only for estimating time-depth relationship and for creating synthetic seismograms but also for estimating Q values. To accurately estimate Q values, a parametric study of one-dimensional wave propagation modeling using ZOVSP data acquisition geometry was conducted. It was found that time/spatial sampling intervals affect Q value estimation. Considering the results of the parametric study, various one-dimensional velocity models were constructed, and preliminary results evaluating seismic wave attenuation characteristics using the spectral ratio method will be reported at the SEGJ conference"	11) Parametric study of 1D seismic wave propagation modeling for Q-value estimation: Evaluation of the seismic wave scattering and intrinsic attenuation properties
		*Hiromu Otsu・Jun Matsushima(1) 1:The university of Tokyo,
Dec.5	9:50 - 10:10 "To obtain high-quality seismic imaging, the National Program for Oil and Gas Prospecting has adopted pre-stack depth migration (PSDM) as an alternative to pre-stack time migration (PSTM) since 2023. We present the first PSDM result in this Program, which is acquired in a highly folded and thrusted area. A velocity model for PSDM is constructed using beam migration and travel-time tomography, and the model is additionally refined by full waveform inversion applied to the shallower portions to delineate localized velocity heterogeneity. Compared to PSTM, PSDM successfully addresses imaging challenges in thrusted areas such as sub-thrust structures which are potential candidates for hydrocarbon traps. The improved structural imaging contributes to reducing the uncertainty of data interpretation and extracting new leads, unlocking new hydrocarbon potentials."	12) Depth Migration in the National Program for Oil and Gas Prospecting
		*Yuki Kawano(1)・Kenji Nakajima・Waka Komatsu(2)・Shun Harigaya・Toshiko Furukawa(1)・Andrew Wu・Steve Novosel(2) 1:JOGMEC,2:OGF
Dec.5	10:10 - 10:30 "This paper treats the code construction in order that in underground survey, multiple signals from vibration sources at the respective separated positions are transmitted simultaneously and the object signals are detected without interference by the receivers at the other positions. Derived from discrete Fourier transform, periodic orthogonal real-valued sequences with low magnitude and a zero-correlation-zone are generated. The parameters of sequence period, sequence family and zero-correlation zone are selective. A code is made from a train with block pulse weighted by sequence value. The performance of this method is verified by the simulation that for an underground reflection model of horizontal distance 20[m], depth 5[m] and attenuation 1[dB/m], two codes from the sequences with period 635 and maximum magnitude 1.74 are transmitted simultaneously and detected independently under existence of noise. This method of code division multiplexing can escape the long measurement time as conventional chirp method."	13) Source Waveform Coding Method for Multi-Channel Seismic Survey by Simultaneous Exciting of Seismic Sources
		*Yoshihiro Tanada(1)・Masato Iguchi(2)・Tomoki Tsutsui・Haruhisa Nakamichi(1) 1:DPRI Kyoto University,2:Kagoshima City Office
Dec.5	10:30 - 10:50 "Seismic wavefield gradients are becoming increasingly accessible in the field due to advancements in seismic sensors such as rotational sensors and distributed acoustic sensing (DAS). A key characteristic of wavefield gradients is their significant sensitivity to sub-wavelength heterogeneities compared to conventional seismic measurements of translational motions. In this work, we explore the potential of wavefield gradients for locating small-scale subsurface anomalies, with a particular focus on the use of DAS for detecting such heterogeneities. "	14) Locating small scale heterogeneities with DAS
		*Kota Mukumoto(1)・Yann Capdeville(2)・Tatsunori Ikeda(3)・Donatienne Leparoux(4)・Tsuji Takeshi(5) 1:JAMSTEC,2:Nantes Université, CNRS, Laboratoire de Planétologie et Géosciences,3:Kyushu University,4:GERS-GeoEND,Université Gustave Eiffel,5:Tokyo University
Dec.5	10:50 - 11:10 "We are developing a system to conduct active seismic exploration using a single ultra-compact seismic source and a single seismometer.Although the seismic source developed in this study is small, it continuously generates signals, which are then stacked to transmit the source signal over long distances. By installing the seismic source and seismometer on a rover and a lander, we can reveal the three-dimensional geological structure (S-wave velocity) down to a depth of 10 meters through surface wave analysis. Our field experiment in Mt Fuji demonstrates that 2D S-wave velocity model can be estimated from this source-receiver system. Furthermore, by equipping two rovers with both a seismic source and a seismometer, we are trying to develop an autonomous seismic exploration system capable of investigating depths of several hundred meters using reflection and refraction seismic methods. These seismic surveys utilizing longer-offset data enable the exploration of deeper subsurface structures in extraterrestrial environments, such as the Moon, Mars, and other solid planetary bodies."	15) Autonomous Exploration System Using Small Rovers on the Moon and Earth
		*Takeshi Tsuji・Imam Tarek・Arata Kioka・Kazutoshi Sakamoto・Keisuke Onodera(1)・Fumitoshi Murakami・Hitoshi Tsukahara・Kimiaki Ochi・Naoshi Aoki・Susumu Abe(2)・Satoshi Tanaka・Junichi Haruyama(3) 1:U. Tokyo,2:JGI,3:JAXA
Dec.5	11:10 - 11:30 "The use of Distributed Acoustic Sensing (DAS) measurement with fiber optic cables is promising for monitoring CO2 underground storage due to its suitability for long-term installation and high-density reception. Surface Distributed Acoustic Sensing (S-DAS) measurements, which primarily monitor shallow subsurface areas by deploying cables on the ground surface, raise concerns about the impact of coupling and installation direction on amplitude. When applying S-DAS measurements to natural earthquake observations, these impacts could affect the estimation of earthquake magnitude.	16) Impact of Fiber Cable Installation Conditions in S-DAS Measurements on Earthquake Magnitude Estimation
		*Ryohei Naruse・Yuki Kobayashi(1) 1:INPEX


Session	[Geothermal Energy1][Volcano1]
Chair	Tsutomu Ochiai (Kanagawa University)

Dec.5	13:00 - 13:20 "A seismic experiment and its products are reported. The seismic experiment includes airgun blasting in a pit which is constructed in pumice layers in Sakurajima, south Kyushu, as a pilot experiment for Time-lapse Seismic Volcano Monitoring (TSVM). TSVM aims active monitoring of magma or volcanic fluid movement with using controlled source seismic method. It is fundamental to prepare stable seismic source with steady source signature over repeating experiments for precise evaluation of seismic response from depth. The funnel shaped airgun pit with 10 meters depth and 2.5 meters diameter was provided with heavily reinforced concrete for the experiment. Twenty detonations were made and seismograms were obtained in the range up to about six and half kilometers. Relative body wave efficiency and the final state of the pit are presented, and what is next will be presented."	17) Seismic airgun blasting in a pit within pumice layers, as a pilot experiment for Time-lapse Seismic Volcano Monitoring
		*Tomoki Tsutsui(1)・Masato Iguchi(2) 1:Kyoto University,2:Kagoshima City
Dec.5	13:20 - 13:40 "One of the subsurface changes that occur with production activities such as geothermal power generation and hot spring use is the pressure drops inside geothermal reservoirs and gas saturation increase due to excessive production. To sustainably utilize geothermal resources, it is important to develop and improve methods for monitoring such changes in reservoir conditions. We conducted repeated micro-gravity measurements and microtremor observations in Beppu geothermal area. Irregular gravity and velocity changes were observed during the measurement period in the active production area. This is due to changes in saturation in the reservoir caused by production activities, and the period of rapid decrease in velocity is considered to indicate vaporization in the reservoir. Using both methods together has the advantage that the analysis conditions (bandpass filter, lag time) that reflect the saturation change can be estimated while referring to the gravity change when calculating the velocity change. The velocity change of the microtremor is able to supplement the information on the phase change."	18) Geothermal Reservoir Monitoring by Repeated Micro-gravity Measurements and Microtremor Observations
		*Yohei Morifuji(1)・Hiroaki Sato・Masayuki Kuriyama・Kenji Kubota(2)・Jun Nishijima(3) 1:CRIEPI,Kyushu University,2:CRIEP,3:Kyushu University
Dec.5	13:40 - 14:00 "We carried out the second geophysical survey in Kijiyama geothermal field using optical fiber in a geothermal well. We obtained temperature depth profile using DTS (Distributed Temperature Sensor) and seismic record by DAS (Distributed Acoustic Sensor) and surface seismic seismometers for twelve seismic excitations surrounding the wellhead. The temperature was 296?C at 2,070 m depth. We used the DAS records at the depth up to 1,665 m where temperature did not exceed 270?C. We obtained a 3D Vp structure model using the borehole DAS and surface seismometer records in 2022 and 2024. The synthetic waveforms of DAS and surface seismic records using the 3D Vp model satisfy the first P arrivals of seismic dataset. The new 3D Vp structure is updated from the results obtained in 2022, and covers the much wider area than that in 2022. In the western side of Kijiyama field, the higher Vp layer than 4.5 km/s reached 500 m depth. In the northern area, Vp = 3.5 km/s exists at the depth to 1 km."	19) The second geothermal exploration using the DAS in the Kijiyama geothermal borehole, Yuzawa, Akita.: Preliminary report
		*Junzo Kasahara・Yoko Hasada(1)・Masaru Suzuki・Tomohiro Takahashi(2)・Hisashi Kadonokuchi(1)・Yoshihiro Fujise(3) 1:ENAA,2:TOUSEC,3:WELMA
Dec.5	14:00 - 14:20 "Temporary seismic observations were conducted twice at Hachijojima, from September 2019 to March 2020 and from September 2021 to March 2022. The purpose is to explore the internal structure of Hachijojima Volcano. This study calculated the H/V spectral ratio from the three-component continuous seismic records observed in these observations and estimated the subsurface velocity structure. To investigate the similarity of the shape of the H/V spectral ratio among the stations and its spatial distribution, we used clustering using Ward's method, a type of hierarchical agglomerative clustering with the cross-correlation coefficient as the distance. The velocity structure was estimated from the H/V spectral ratio using the Monte Carlo method. The spatial distribution of the clusters, the velocity structure of each cluster, and their correspondence with the volcanic geology are not necessarily clear, there may be some correspondence with the formation age of Higashiyama and Nishiyama volcanoes and the distribution of lava flows."	20) Spatial distribution and velocity structure of H/V spectral ratio obtained using seismic observation records on Hachijojima island
		*Toshiki Watanabe(1)・Yoshiya Oda・Hiroyuki Azuma(2) 1:Nagoya Univ.,2:Tokyo Metropolitan Univ.
Dec.5	14:20 - 14:40 "We applied two different earthquake detection models based on the machine learning to extract earthquakes from the observation results of seismometers temporarily installed on a volcanic island. One model treats earthquake waveforms as images, while the other treats them as time series data. The former treats the P-wave initial motion, S-wave initial motion, and noise as images, respectively, and uses a convolutional neural network (CNN) to determine the initial motion of the earthquake. On the other hand, the latter treats the seismic waveform as data that has noise, P-wave, and S-wave as like the order of natural language, and uses the self-attention technology to determine the initial motion. On the island, there is frequent and strong noise caused by the swaying of trees due to waves and strong winds. Furthermore, temporary earthquake observation is carried out with the assumption of removal, so it is easy to pick up noise. As a result of applying both methods to these observation records, the method that treats them as series data showed higher detection performance than the method that treats them as image data."	21) Evaluation of the earthquake detection performance of machine learning models using temporary earthquake observation records in Hachijojima
		*Hiroyuki Azuma(1)・Hikaru Kunimasa(2)・Adrianto Widi Kusumo・Yoshiya Oda(1)・Toshiki Watanabe(3)・Toshifumi Matsuoka(4) 1:Tokyo Metropolitan University, 2:Tokyo Gas Co., Ltd.,3:Nagoya University,4:Fukada Geological Institute


Session	Executive Lectures
Chair	Terumasa Yamane (Geophysical Surveying Co., Ltd.)

Dec.5	15:00～16:00	Noriaki Higashi (Saitobaru Archaeological Museum of Miyazaki Prefecture)
Dec.5	16:00～17:00	Masahito Suiko (University of Miyazaki, The Center of Food Safety Analysis)


Dec.5 　　Room 2 (Main Conference Room, 4F)

Session	[Groundwater][Civil Engineering3][Soil]
Chair	Kunio Aoike (OYO Corporation)

Dec.5	9:30 - 9:50 "The phenomenon of induced polarization (IP), which is caused by capacitive materials when an electric current is applied to the ground, is being used in the U.S. and Europe to improve the accuracy of structural interpretation, such as the evaluation of hydraulic conductivity. However, the geological structure in Japan is complex compared to the stable geological structure in Europe and the U.S. Therefore, the latest findings can be applied to Japan. Therefore, we conducted a study in the Nishi-Niregawa River basin, where a clayey layer with IP effect exists, to confirm whether the latest findings are applicable to Japan. The measurement results were analyzed using pyGIMLi, an open source library, and discussed based on borehole investigations and resistivity surveys conducted in the area. As a result, anomalies that could not be identified in the resistivity distribution were identified in the charge rate distribution, suggesting the possibility of selectively detecting clayey layers by measuring the IP effect."	38) Time-domain IP electrical survey for accurate interpretation of subsurface structure: a case study in the Nishi-Niren River basin
		*Watanabe Aoi・Komori Shogo・Kamimura Kento・Ichikawa Masayuki(1) 1:AIST
Dec.5	9:50 - 10:10 "To enhance the accuracy of geological structure interpretation, we are advancing the DCIP method, which can reveal subsurface IP characteristics in addition to traditional resistivity. A robust method has been developed to convert time-domain data obtained from time-domain IP (TDIP) method into spectral IP characteristics. This paper reports the results of applying this method to TDIP electrical exploration data conducted in the Nishinire River area, where river sediments are present."	39) Application of advanced time domain IP (TDIP) method in sedimentary layers
		*Shogo Komori・Aoi Watanabe(1) 1:AIST
Dec.5	10:10 - 10:30 "Ground-penetrating radar (GPR) is a device which measures the scattering response of electromagnetic waves at a boundary with different dielectric constant. Therefore, it has high sensitivity to detect moisture, which significantly changes the dielectric constant of the ground. However, GPR is frequently difficult to detect the moisture transition zone (MTZ) above the groundwater table, because shallow ground has many scatterers. Therefore, the authors proposed a time-shift method for detecting MTZ using 2-D cross-correlation analysis of GPR records acquired in the fluctuation of groundwater levels. Our results show the time-shift method can detect MTZ in the ground with many scatterers. GPR which can acquire the groundwater distribution will be a useful survey technique for ground condition management."	40) Detecting water-table fluctuations by two-dimensional cross-correlation analysis of ground-penetrating radar sections
		*Kyosuke Onishi・Nozomu Suzuki(1) 1:Public Works Research Institute
Dec.5	10:30 - 10:50 "Physically-informed neural networks (PINNs) are beginning to be widely used as a new simulation method. However, conventional networks lack the ability to flexibly respond to applied conditions (generalization ability). This is because they cannot handle continuous functions for the network input and output. To solve this problem, several methods have been proposed that can learn the deep learning mapping operator itself. In this study, we report on the use of one such method, DeepONet, to solve the problem of calculating hydraulic head values from hydraulic conductivity distribution specified boundary conditions."	41) On the generalization ability of physics-Informed Neural Networks
		*Matsuoka Toshifumi(1) 1:Fukada Geological Institute
Dec.5	10:50 - 11:10 "Fault zone conductors along active faults can be visualized by magnetotelluric (MT) method. However, the spatial resolution of MT surveys is not sufficient to distinguish the detailed three-dimensional (3D) fault structure such as heterogeneous rupture distributions at earthquakes. In this study, we conducted spatially high-density audio-frequency MT (AMT) survey around the Futagawa fault, where distinct surface ruptures exist in 2016 earthquakes. We estimated 3D resistivity structure from the surface to the depth of about 1 km by using a 3D inversion procedure. As a result, at about 100 m below the surface, we found a discontinuous distribution of small-scale conductive bodies along the surface ruptures. At the deeper depth, two independent conductive bodies are found along both outsides of the Kiyama-Kashima graben. We also found that those conductive bodies are connected to each other at a depth of about 1 km. The former discontinuity suggests that the high pore zone in the shallow subsurface is related to the heterogeneous distribution of near-surface ruptures due to past earthquakes. The latter is considered to be visualized as the branching of shallow sub-faults from the main deep fault, and also suggests that the distribution of fractures is asymmetric along the fault."	42) Relationship between the near-surface resistivity structure and distribution of surface rupture around the Futagawa fault, Japan.
		*Nagi Yamashita・Tada-nori Goto・Keiichi Ishizu・Rei Amano・Souma Yamamoto・Yasuhiro Sugitani・Nana Fujiwara・Naoki Takahashi・Mao Monden(1)・Satoru Yamaguchi(2) 1:University of Hyogo,2:Osaka City University


Session	[Infrastructure Maintenance Management][Buried Object][Structure]
Chair	Yasutomo Yamauchi (Dia Nippon Engineering Consultants)

Dec.5	13:00 - 13:20 "While gravity methods are typically used in qualitative manners, there are several approaches to quantitatively estimate the depths of anomaly sources from gravity measurements. Among those, we applied three empirical methods, two graphical methods and a power spectrum-based method, to estimate the depth of lava tunnels. The results successfully delineate low gravity anomalies that well correlate with the known shape and depth of the lava tunnel with the accuracy of several meters. In this paper, we review the methods and discuss the accuracy in the estimates from each quantification method."	43) Delineation of subsurface cavity by using microgravity method
		*Masatoshi Yagi・Yuto Sasaya・Ken Yokota(1)・Souichirou Sawada・Katsuya Noda(2) 1:JGI, Inc.,2:GEOSYS, Inc.
Dec.5	13:20 - 13:40 "Recently, an estimation equation based on surface wave attenuation has been proposed as an efficient method for estimating the depth of surface cracks in concrete structures. In a previous study, the attenuation of surface waves was measured using a concrete specimen with a simulated crack, and the crack depths were estimated based on this estimation formula. The results showed that the estimated depths tended to be deeper than the actual depths. The reason for this is suggested to be a significant loss of energy during the passage of the simulated crack, and may complicate the wave propagation. In this study, we performed measurements again using concrete specimen with simulated crack in order to visualize the wave field of surface waves and to understand their behavior in detail. The results showed that the surface waves propagated in concentric rings, were partially disrupted, and attenuated significantly when they passed through the crack. A difference of 50 m/s in the propagation velocity was observed between the two areas bounded by the cracks, indicating that there may be a 10% difference in the coarse aggregate volume fraction."	44) Visualization of Surface Wave Propagation Behavior in Cracked Concrete Specimens
		*Nahoko Akiyoshi・Hiroyuki Azuma・Kentaro Ohno・Yoshiya Oda(1) 1:Tokyo Metropolitan Univ.
Dec.5	13:40 - 14:00 "The author has developed a new method that determines not only buried pipelines but also the signs of the reflection coefficients automatically in dense GPR data. If it is calculated the averaged cosine of the instantaneous phase along the hyperbolic wave front, the cosine approaches to the absolute value 1 on the line of buried pipe. From the result of applying the measurement data at our test site, the sign of the reflection coefficient could be estimated from the pattern of the cosine of the instantaneous phase. I think that the method will provide an important key for identifying the type of pipes."	45) Simultaneous automatic determination of buried pipelines and reflection coefficients sign using instantaneous phase of GPR data
		*Kunio Aoike(1) 1:OYO Corporation
Dec.5	14:00 - 14:20 "In this study, to test the usefulness of sparse coding with dictionary learning, we considered a situation in which the density structure of the subsurface was estimated by muon tomography and ran into an inferior decision problem due to insufficient data. We showed that ADMM with dictionary learning can be applied in this situation to reconstruct the target subsurface density model with essentially the same accuracy as ADMM with Total Variation regularization. We showed that ADMM with dictionary learning can provide more accurate estimation than ADMM with Total Variation regularization, especially for the subsurface density model with low sparsity. Future prospects include the validation of the effectiveness of each method for various possible situations in actual geophysical exploration and the improvement of the accuracy of dictionary learning."	46) Muon tomography with sparse coding using dictionary learning
		*Ryohei Nakano(1)・Masashi Kodama・Toshiyuki Yokota(2)・Jun Matsushima(1) 1:The University of Tokyo, National Institute of Advanced Industrial Science and Technology,National Institute of Advanced Industrial Science and Technology,The University of Tokyo
Dec.5	14:20 - 14:40 "The island-arc-scale subsurface resistivity structure in Japan is required to predict and prevent disasters caused by geomagnetically induced currents (GIC) effectively. No nationwide electromagnetic observations have ever been conducted in Japan, and no such large-scale resistivity structure was obtained. As is known well, both resistivity and seismic velocity are functions of temperature, and the large-scale three-dimensional structure of seismic velocity is available in Japan. Therefore, we focus on an image-based deep learning technique. In this study, using deep learning, we try to estimate the resistivity structure from seismic velocity by learning the relationship between subsurface resistivity images and seismic velocity images. As the deep learning, pix2pix (Isola et al., 2017) was used: an image generation tool based on the adversarial generative network (GAN). The data used here is 1200 paired images of synthetic resistivity and seismic velocity, which are calculated from various subsurface temperature patterns. The estimation results by pix2pix indicates high accuracy for prediction of resistivity structures. The average error of estimation is within a few Ωm. In future, the evaluation of resistivity structure in the Aso volcanic region, Kyushu, will be tested for validation of the effectiveness of our scheme."	47) An attempt to infer resistivity structure from seismic velocity structure using deep learning
		*Souma Yamamoto・Tada-nori Goto(1) 1:Univ.Hyogo


Dec.6 　　Room 1 (Gallery 1, 4F)

Session	[Resource Exploration4][Geothermal Energy2][Other]
Chair	Naofumi Nakamura (NGP)

Dec.6	9:30 - 9:50 "The Geological Survey of Japan (GSJ), AIST has been conducting developments of drone magnetic survey systems and has established the special attention applying to drone magnetic survey. Based on the special attention, drone magnetic surveys have been conducted to collect the information related to the risk assessment of landslide: one over the Yoshioka area, Minamiaso Village, Kumamoto Pref. on the western flank of central cones of Aso volcano and the other over a landslide area in Yufu City, Kumamoto Pref. Although these survey areas comprise volcanic rocks attributable to high magnetic anomalies in general, relatively low magnetic anomalies were observed over the fumarolic and landslide areas in Minamiaso Village and over the landslide area in the sediment disaster special alert areas of Yufu City. Once these low magnetic anomalies are caused by paramagnetic cray minerals formed by hydrothermal alteration, there is a possibility to estimate hydrothermally altered aeras by ultra high-resolution aeromagnetic survey."	22) Drone magnetic surveys for the risk assessment of landslide applied to mapping of hydrothermal alteration areas
		*Shigeo Okuma・Ayumu Miyakawa・Keiichi Sakaguchi・Hideo Hoshizumi・Tomoya Abe・Keiya Yoneoka・Hiroaki Koge(1)・Hikari Yonekura(2)・Daisaku Kawabata・Yoshinori Miyachi(1) 1:AIST,2:Previously AIST
Dec.6	9:50 - 10:10 "Assessment of geothermal resource potential requires geological information of geothermal fluids, source and reservoir which constitute three main elements of hydrothermal system. The distribution of the latter two elements can be evaluated appropriately through applying gravity and aeromagnetic data for stand-alone and integrated correlation analysis. The case study in Shimokita peninsular, Tohoku district shows the potential regions where vertical fracture reservoirs are to be formed by rhyolite/dacite intrusions, some formed volcano into tuff layers as well as those of horizontal caused by lava deposit with thermal joints. Low flight height and high acquisition density aeromagnetic survey is recommended to conduct to improve the obtained preliminary assessment."	23) Gravity Aeromagnetic Integrated Analysis in Volcanic Area
		*Shigeki Mizutani(1) 1:KGE
Dec.6	10:10 - 10:30 "This paper shows preliminary results of Curie point depth (CPD) analysis of the Okinawa sea area using East / Southeast Asia magnetic anomaly map compiled by GSJ. The analysis method is Bouligand, et al. (2009) based on fractal theory. This analysis result was combined with the heat flow data. CPDs in the case of 50 km window size are ranging 7-10 kmBSL or 7-9 km below sea floor. CPD is shallower than 8 kmBSL at the Iheya Minor Ridge and about 9-10 kmBSL at the Iheya North Knoll. The heat flow data show local thermal structures which are not detected by CPD analysis due to the average effect. A challenge is conducting CPD analysis using additional observation data obtained by drones, etc., to contribute to a model of submarine geothermal system for resource assessment."	24) Curie point depths analysis for submarine geothermal resources in Okinawa sea area
		*Yasukuni Okubo・Shoichi Yamano・Kazumi Osato・Masatake Sato・Tatuya Sato(1)・Takeya Nakabayashi(2) 1:Geothermal Energy Research & Development Co. LTD.,2:Mitsui O.S.K. Lines, Ltd.
Dec.6	10:30 - 10:50 "S-DAS is a DAS measurement using optical fibers installed on the ground surface and is one of the important sensing technologies. To further improve the usefulness of S-DAS, we applied a machine learning approach to estimate the vertical velocity field measured by a geophone from the S-DAS records, corresponding to a horizontal strain rate. In the machine learning model, the S-DAS records were used as an input and the vertical velocities were used as an output. LSTM was used for the neural network architecture for learning and validation. We applied our neural network architecture for both pseudo synthetic and real data. As a result, the vertical velocity could be estimated well from the S-DAS records using synthetic data. We also found that the number of S-DAS records used for learning has a large effect on the estimation accuracy. The application to real data allowed the vertical velocity to be estimated well in some sections. In the future, it would be possible to further improve the estimation accuracy by improving the quality of the recorded data. This research demonstrated the possibility to estimate vertical velocity field from S-DAS records even in real data."	25) Estimation of vertical velocity from horizontal strain rate measured by surface DAS records using machine learning
		*Takuto Amano(1)・Yuki Kobayashi・Ryohei Naruse(2)・Tatsunori Ikeda(1) 1:Kyushu Univ.,2:INPEX
Dec.6	10:50 - 11:10 "We analyzed temporal velocity changes (dv/v) over 10 months using coda wave interferometry with a continuously operating vibration source, namely Accurately Controlled Routinely Operated Signal System (ACROSS). The coda waves generated by ACROSS were recorded by a seismic array located approximately 3 km away in western Shizuoka Prefecture (Morimachi). We calculated the transfer function of the ACROSS signal and subsequently identified and extracted the coda waves after the surface wave arrival. Coda wave interferometry was applied to extract dv/v. By comparing the extracted dv/v with environmental factors such as rainfall, temperature, and seasonal changes, we found sinusoidal-like long-term and clear short-term changes associated with rainfall. We removed the long-term trend and then analyzed the short-term changes, which can be attributed to pore pressure changes induced by rainfall."	26) Estimation of temporal changes in seismic wave velocity using coda wave interferometry with an accurately controlled seismic source
		*Feng Chen・Toshiki Watanabe(1)・Ryouya Ikuta(2)・Koshun Yamaoka(1)・Shuhei Tsuji(3) 1:Nagoya University,2:Shizuoka University,3:Japan Agency for Marine Earth Science and Technology


Dec.6 　　Room 2 (Main Conference Room, 4F)

Session	[Civil Engineering4][Earthquake3][Disaster Prevention3]
Chair	Haruhiko Suzuki (OYO Corporation)

Dec.6	9:30 - 9:50 "This study focuses on effects of reflected and refracted waves on Rayleigh wave phase velocity estimation in two-layered horizontally ground model. The theoretical amplitude attenuation of Rayleigh and reflected waves are calculated, considering geometric attenuation, inelastic attenuation and reflection coefficients. Rayleigh waves attenuate at higher frequencies and larger propagation distance compared to reflected waves. Synthetic waves on the model surface are also calculated. F-K spectra of the synthetic waveform include not only spectra of Rayleigh waves but also those of reflected or refracted waves, which overestimates the phase velocity of Rayleigh waves. If the velocity boundary is closer to the surface and the velocity contrast is greater, the effect of reflected and refracted waves can be larger to generate biases in the phase velocity estimation."	48) Effect of reflected and refracted waves on Rayleigh wave phase velocity estimation in horizontally layered ground
		*Shuntaro Miyanaga(1)・Hiroaki Yamanaka・Seiji Tsuno(2) 1:Taisei Corporation,2:Tokyo Inst.
Dec.6	9:50 - 10:10 "To monitor variations in the soil characteristics of a collapsed slope, an optical fiber cable was installed near the collapse site. In this study, surface wave exploration was performed using distributed acoustic sensing (DAS) measurements through the common midpoint (CMP) cross-correlation method to estimate the S-wave velocity structure. Furthermore, continuous observational data - including active source records and ambient noise - were analyzed via CMP processing, with frequency-phase panels computed from cross-spectral gathers for each CMP. The dispersion curves derived from both the active and quasi-passive explorations exhibited strong consistency, indicating that passive exploration using DAS is a viable approach for monitoring the soil properties of slopes."	49) Estimating S-wave Velocity Structure Using Distributed Acoustic Sensing with Fiber Optics in a Shallow Subsurface for slope Monitoring
		*Yasutomo Yamauchi(1)・Yoshihiro Sugimoto(2)・Hiroyuki Takaoka・Shoji Seno・Michio Imai・Yuichi Yoshimura(3)・Makoto Nishigaki(4)・Nishimura Akira(5) 1:Dia Nippon Engineering Consultants ,2:geotomo-lab,3:Kajima Corporation,4:IMTERA,5:Okayama Soil Laboratory
Dec.6	10:10 - 10:30 "We have conducted an observation of earthquake ground motion for an acquisition of basic data for building of models for deep sedimentary layers to predict long-period strong motion of anticipated earthquakes in Lima, Peru. The observation instrument which consists of a high-sensitivity 3-component accelerometer, a vertical velocity meter, and a data logger was carefully selected to observe long-period motion due to distant events. Seven instruments have installed in the southern part of Lima since August 2022. Earthquake records including long-period motion were obtained from 30 distant events in the last 1 year. We found a large amplification of the long-period ground motion in a frequency range from 0.3 to 1 Hz at the stations near the coast of Lima. A high-frequency amplification is dominant at the inland stations suggesting minor effects of the deep sediments."	50) Observation of Long-Period Ground Motion for Model-Building of Deep Sedimentary Layers in Lima, Peru
		*hiroaki yamanaka・Hiroe Miyake・Koji Miyakawa・Miwako Ando(2)・Hisao Kondo(3)・Gerson CARRASCO・Carlos GONZALES・ Zenon AGUILAR(4) 1:Tokyo Inst. Tech.,2:Earthq. Res. Inst., The Univ. Tokyo, 3:Geological Survey of Japan, AIST, 4:Japan Peru Center for Earthquake Engineering Research and Disaster Mitigation
Dec.6	10:30 - 10:50 "We estimated a two-dimensional S-wave velocity structure of the deep sedimentary layers for major urban areas in Bursa, Turkey with a waveform inversion to reproduce the strong ground motion generated by the M7.1 earthquake in 1855. Observation records show that Love waves with a predominant frequency of approximately 1 Hz are propagated in areas slightly away from the edge of the basin. It was found that these Love waves can be reproduced with the model whose sedimentary layers become thick away from the edge of the basin."	51) Evaluation of 2D Deep S-wave Velocity Structure with Waveform Inversion of Earthquake Ground Motion Record in Bursa, Turkey
		*Kentaro Kasamatsu(1)・Hiroaki Yamanaka(2)・Hiroe Miyake(3)・Masashi Morita(4)・Daiki Sato(2) 1:Kajima Tech. Res. Inst.,2:Tokyo Inst. Tech.,3:Earthq. Res. Inst., Univ. Tokyo,4:Yokohama National Univ.
Dec.6	10:50 - 11:10 We carried out the surface wave exploration by multi-channel active source and microtremor array measurements to evaluate the phase velocity change under groundwater level fluctuation by water injection. We set the artificial irregularity by sand backfilling it to determine the detection performance for irregularity and the effect of underground water level. We injected water into this backfilled trench. We observed the surface wave method with short interval geophones and array measurement with a short radius to grasp the phase velocity changes. We can see that the recorded waveforms are changed with increasing water levels. The phase velocities of the high water level are higher than those of the lower level.	52) Evaluation of the Phase Velocity Change in the Multi-Channel Surface Wave Exploration Method Under Groundwater Level Fluctuation by Water Injection
		*Nobuo Takai(1)・Michiko Shigefuji(2)・Seiji Tsuno(3)・Naohumi Nakagawa(1)・Shingo Nomoto・Tetsunori Kishikawa(4)・Jun Horita(5)・Syunzo Kawajiri(6)・Takayuki Kawaguchi(7)・Hiroaki Yamanaka(3) 1:Hokkaido Univ.,2:Kyushu Univ.,3:Tokyo Inst.Tech.,,4:Geo-Technical Research Co.,Ltd.,5:Kyushu Inst.Tech.6:Kyushu Univ.,7:Kitami Inst.Tech.
Dec.6	11:10 - 11:30 "For evaluating the effect of groundwater level fluctuation on the shallow subsurface properties, we repeatedly carried out the electrical survey and the GPR survey raising ground water level by water injection. The results are as follows. 1) The electrical survey: As the groundwater level rises,	53) Evaluation of results obtained from electrical survey and GPR survey under groundwater level fluctuation by water injection
		*Shingo Nomoto・Tetsunori Kishikawa(1)・Jun Horita(2)・Hiroaki Yamanaka(3)・Syunzo Kawajiri(4)・Seiji Tsuno(3)・Nobuo Takai・Naofumi Nakagawa(5)・Michiko Shigefuji(6)・Takayuki Kawaguchi(7) 1:Geo-Technical Research Co.,Ltd.,2:Kei Corp.,3:Tokyo Inst.Tech.,4:Kyushu Inst.Tech.,5:Hokkaido Univ.,6:Kyushu Univ.,7:Kitami Inst.Tech.

VENUE
	Miyazaki Citizen's Plaza, 1-1-2 Tachibana-Dori, Miyazaki City, MIYAZAKI, JAPAN [Access Map]

SCHEDULE
	Wed. Dec. 4, 2024
		Openning Speech	Room No.1 (4F)	10:10-10:15
		__Speaker:	Jun MATSUSHIMA (Univ. of Tokyo, GSFS; President of SEGJ)
		Technical Sessions	Room No.1 (Gallery No1, 4F)	10:20-15:10
		Technical Sessions	Room No.2 (Main Conference Room, 4F)	10:20-15:30
		Poster Core Time	Room No.1 (Gallery No1, 4F)	15:50-17:50
		Exhibition	Room No.3 (Gallery No2, 4F)	11:00-17:20

	Thu. Dec. 5, 2024
		Technical Sessions	Room No.1 (Gallery No1, 4F)	09:30-14:40
		Technical Sessions	Room No.2 (Main Conference Room, 4F)	09:30-14:40
		Executive Sessions	Room No.1 (Gallery No1, 4F)	15:00-17:00
		__Chair:	Terumasa YAMANE (Geophysical Surveying Co., Ltd.; Vice-President of SEGJ)
		__Presentation(1):	Ground Penetrating Radar Survey at The Saitobaru Archeological Museum of Miyazaki Prefecture Noriaki HIGASHI (The Saitobaru Archeological Museum of Miyazaki Prefecture)
		__Presentation(2):	Miyazaki's Strengths: The Appeal of Authentic Shochu - From production to tasty drinking, functionality and alcohol constitution Masashito SUIKO (University of Miyazaki, The Center of Food Safety Analysis)
		Exhibition	Room No.3 (Gallery No2, 4F)	09:30-17:00
		Banquet	MRTmicc (4F) [Access Map to MRTmicc]	18:00-20:00
	Fri. Dec. 6, 2024
		Technical Sessions	Room No.1 (Gallery No1, 4F)	09:30-11:10
		Technical Sessions	Room No.2 (Main Conference Room, 4F)	09:30-11:30
		Exhibition	Room No.3 (Gallery No2, 4F)	09:30-11:00
		Field Trip	Saitobaru Burial Mounds and The Saitobaru Archeological Museum of Miyazaki Prefecture	12:30-16:30

Registered and Paid		Pre-Registration (until Nov. 4, 2024)	Onsite Registration
Conference Meeting	Member / Non-member	JPY 7,700-*	JPY 8,800-**
	Student (Member)	JPY 0,000-*	JPY 0,000-**
	Student (Non-member)	JPY 3,850-*	JPY 4,400-**
Conference Meeting	Member / Non-member	JPY 6,600-**	JPY 7,700-**
Conference Meeting	Student	JPY 3,300-**	JPY 3,300-**

**	Pre-registrant will receive PAPER Proceedings by mail before the conference.
**	PAPER Proceedings can be purchased at a price of JPY 1,650-.

DESTINATION
	Saitobaru Burial Mounds
		This is a park dotted with more than 300 burial mounds in a vast plateau, built from the end of the 3rd century to the 7th century.


	Sannai Maruyama Special Historical Site
		The museum is located near the Saitobaru Burail Mounds and is the main exhibition about this group of burial mounds.


SCHEDULE
	Fri. Dec 6, 2024
		Departure from VENUE after the monring technical sessions around 12:30. Visit to Saitobaru Burial Mounds and The Saitobaru Archeological Museum of Miyazaki Prefecture. Arrival at Miyazaki Airport around 16:30.


	More information about the field trip will be sent to those who have pre-registered the field trip.

CANCELLATION
	No Refund Will Be Made.

LIST OF ADVERTISEMENTS
	Geophysical Surveying Co., Ltd.(GSC) Hakusan Corporation ITOCHU Techno-Solutions Corpration(CTC) JGI, Inc. Kawasaki Geological Engineering Co. Ltd.(KGE) Sumiko Resources Exploration & Development Co.,Ltd.

1) Awards of the SEGJ Conference 2) Guide for Technical Session

LIST OF EXHIBITORS
	NANOXEED