

June 04,2025　　Room No.1 (Room05, 2F)

Session	[Civil Engineering1]
Chair	Tomokazu Kurihara (Hakusan Corporation)

Jun.4	10:10 - 10:30 "The capacitively coupled resistivity method is a mobile near-surface prospecting technique that is suitable for long-distance surveys. This technique can be used to find structurally weak points along a river levee. For example, it is effective for delineating the soil structure of river levees or assessing the risk of piping failure caused by foundation leakage. We have developed a new capacitively coupled resistivity survey system which can perform two types of measurements. The first measurement setup is using plate electrodes, and the second is using line electrodes. Plate electrodes are used for a detailed survey of the shallow part of the resistivity structure to assess the risk of piping failure. Line electrodes are used to delineate the soil structure from the levee crown to the foundation ground. This paper introduces an overview of the development."	1) Development of a capacitively coupled resistivity survey system (Part 1): Overview of the development
		*Hiroshi Kisanuki・Chisato Konishi・Kiichiro Sato・Yusuke Kunisue・Shinji Matsuda(1),Philip I. Meldrum・Oliver Kuras(2) 1:OYO,2:BGS
Jun.4	10:30 - 10:50 "We have developed a new capacitively coupled resistivity meter using plate electrodes to assess the risk of piping failure in a river levee. For this purpose, it is important to estimate the soil structure at the toe of the levee, especially the distribution of the permeable sand layer located beneath the impermeable clay layer. Using plate electrodes allows for shorter electrode spacing and a shorter distance between transmitter and receiver dipoles, enhancing the system’s capability of delineating soil structure in greater detail at shallow depth. In this paper, a numerical simulation and field test were conducted to assess the performance of the developed measurement system. As a result, the response of the plate electrodes could be approximated to that of the point electrodes located at the center of the plate electrodes. Furthermore, the developed system could detect non-metallic pipes buried near the surface and reconstruct a resistivity structure similar to that obtained from a more routinely used ERT survey. In conclusion, the measurement system using plate electrodes is an effective method for delineating the detailed shallow part of the resistivity structure."	2) Development of a capacitively coupled resistivity survey system (Part 2): Development of the shallow measurement system using plate electrodes
		*Hiroshi Kisanuki・Chisato Konishi・Kiichiro Sato・Yusuke Kunisue・Shinji Matsuda(1),Philip I. Meldrum・Oliver Kuras・Mihai O. Cimpoiasu(2),Adrian White(3) 1:OYO,2:BGS,3:University of Bristol
Jun.4	10:50 - 11:10 "Geophysical exploration is a technology that was developed by our predecessors, who constructed theories based on ideas and verified them through on-site verification. While we have a responsibility to continue and develop this exploration technology, we cannot imagine it regressing. This time, we summarized the questions about anisotropic arrays and linear arrays, and calculated the SPAC coefficients for five points on a circumference. 1) We found that no demonstration experiments were conducted on linear arrays, and their accuracy was not confirmed. 2) The exploration depth of a linear array is listed in the ""Basic Theory of Microtremor Array Exploration"" as the seismometer deployment length = exploration depth. We found the reason for the low resolution of linear arrays. 3) In the SPAC method experiment on five points on a circumference, the unidirectional SPAC coefficients changed over time. We were able to confirm that linear arrays have poor reproducibility. Linear arrays are listed in the standard cost estimate materials and are used in public works. We would like to have a fair forum for reviewing the theory, experiments, and exploration depth (resolution) of linear arrays.	3) Remarks on the number of observation points and depth of search for the spatial autocorrelation method （３）
		*Hisao Hayashi(1),Toshio Takagi(2),Tsuyoshi Haraguchi(3) 1:Geo-X Consultants corp.,2:Fukken co,.Ltd.,3:STORY
Jun.4	11:10 - 11:30 "Tomio Inazaki (2008) wrote about the use of integrated geophysical surveys in river levee safety assessments, ""For foundation leakage and embankment infiltration, the estimates are several tens to hundreds of meters, and for piping, the estimates are several centimeters to several meters."" Senoh Shinichi (2013) reported that ""with the current accuracy of integrated geophysical surveys, it is difficult to extract sections of only a few meters that are not safe from infiltration."" The velocity obtained by the MASW method is the average velocity of the seismometer deployment section, and the resolution is the seismometer deployment section. The procedure for CMP analysis is as follows. 1) Rearrange using the CMP method 2) Analysis using the MASW method If the resolution of high-precision surface wave surveys was the same as that of MASW, then what Hayashi Koichi (2001) wrote, ""We have developed a surface wave CMP analysis that can obtain velocity structures with higher resolution by developing MASW,"" would be incorrect."	4) Remarks on the number of observation points and depth of search for the spatial autocorrelation method （４）
		*Hisao Hayashi(1),Toshio Takagi(2),Tsuyoshi Haraguchi(3) 1:Geo-X Consultants corp.,2:Fukken co,.Ltd.,3:STORY
Jun.4	11:30 - 11:50 "A relationship between the array size and maximum observable wavelength is studied by simple exercises using a reverse procedure in the SPAC method. At first, the SPAC coefficient is calculated from a given phase velocity dispersion curve. Then, measurement error is added to the SPAC coefficient, and the phase velocity is estimated by the SPAC method. The maximum observable wavelength is calculated from the minimum frequency at which the error between the actual and estimated phase velocity falls in the acceptable range. The same calculation is carried out to several array sizes, and the result is shown with respect to array size. A difference between SPAC and ESPAC in the phase velocity estimation is described as a reference. "	5) Study on investigation depth and array size of microtremor array measurement
		*Chisato Konishi(1) 1:OYO
Jun.4	11:50 - 12:10 "If Love wave phase velocity can be used in microtremor array surveys, it will help improve the accuracy of model estimation. In addition, a triangular array is generally used for microtremor observations, but if a linear array can be used, the work can be made more efficient. In this study, the phase velocity and power ratio of Love waves were estimated by the three-component spatial autocorrelation analysis using microtremor records observed with a densely arranged array of 19 three-component velocity meters at 5m intervals in a straight line at the ground of Iwate University. The estimated phase velocity of Love waves was ranging from 450 m/s to 200 m/s in the frequency range from 4Hz to 11Hz. The Love wave power ratio was approximately 50 to 80 %. The estimated phase velocities were almost consistent with those calculated from the Vs model. It was also consistent with the phase velocity of previous studies that analyzed using a triangular array. This study demonstrated the effectiveness of an use of a linear array in Love wave phase velocity analysis in microtremor array surveys."	6) Estimation of phase velocity of Love wave based on microtremor records observed with a linear array by three-component spatial auto-correlation method
		Ayumi Omukai・*Hidekazu Yamamoto・Tsuyoshi Saito(1),Katsuya Noda・Rohei Manya・Takashi Suzuki(2) 1:Iwate Univ.,2:Geosys
Jun.4	12:10 - 12:30 "We are developed a new seismic wave analysis tool (phase coherence filter), which detect weak but coherent signals through reducing incoherent noise for array seismic data. This tool uses the ""Phase slant stack"" which is based on the ""Phase weighted stack"" technic. Phase slant stack is derived from the local slant stack for phase component of analytical trace recorded in neighboring receivers and it measures coherence (phase coherence). Phase slant stack analysis generates new 2 attributes. First one is “maximum coherence” in slowness scan range. Second one is “apparent local slowness” at which phase coherence takes maximum. Using these attributes, we can apply “phase coherent filter”. Also, applying restricted apparent slowness range, this tool can reduce coherent noise."	7) Seismic data analysis using phase coherence
		*Makoto Okada (1) 1:NC Geophysical survey


Session	[Urban Geology][Earthquake1][Disaster Prevention1]
Chair	Kunikazu Yoshida (University of Fukui)

Jun. 4	13:50 - 14:10 "This paper compares the cross-correlation function obtained by applying seismic interferometry to the vertical components of a two-dimensional linear array microtremor record with the phase velocity obtained by surface wave exploration. It is known that the two-dimensional linear array microtremor records can be used to estimate the depth of the ground deeper than the depth that can be explored by the surface wave method, but the consistency between the two methods is not clear. Therefore, the authors conducted two-dimensional linear array microtremor measurements and surface wave exploration on a road in the Higashiyama Campus of Nagoya University. Two-dimensional linear array microtremor recordings showed phase velocities from 3 to 16 Hz, which corresponded to the theoretical phase velocity of Rayleigh waves based on nearby PS logging data. On the other hand, the surface wave method obtained phase velocities from 10 to 50 Hz, but the surface wave method gave slower velocities in the frequency range common to both methods. The surface wave survey recorded slower propagation closer to the excitation point, which may be a reason for the slower phase velocity evaluation."	8) A Study on Application of Microtremor Records for Estimating Two-Dimensional S-wave Velocity Structure Part 1: Comparison with phase velocity by surface wave method
		*Hirohito Takahashi(1),Haruhiko Suzuki(2),Takashi Hirai・Kotaro Sueki(3),Masafumi Mori(4) 1:Meijo University,2:OYO corporation,3:University of Hyogo,4:Nagoya University
Jun. 4	14:10 - 14:30 "This paper presents an attempt to infer phase velocities from cross-correlation functions obtained by applying seismic interferometry to the horizontal components of two-dimensional linear array microtremor records. The cross-correlation functions between array stations for the horizontal components of the microtremor records show that the phase propagation of the radial component is similar to that of the vertical component, while the transverse component propagates slightly faster than the vertical component. Applying MASW analysis to the cross-correlation function, vertical and radial components generally coincide at frequencies below 5 Hz, but in the lower frequency range, the phase velocity of radial component is slightly faster than the phase velocity of UD components due to the influence of higher-order modes. Comparing the phase velocity of the Love wave with that of the transverse component, the observed data tended to be slightly faster. The phase velocities of the cross-correlation functions between the vertical and radial components were generally consistent with the phase velocities of the vertical component."	9) A Study on Application of Microtremor Records for Estimating Two-Dimensional S-wave Velocity Structure　Part 2: Detection of phase velocity using horizontal components
		*Haruhiko Suzuki(1),Hirohito Takahashi(2),Takashi Hirai ・Koutaro Sueki(3),Masafumi Mori(4) 1:OYO corporation,2:Meijo University,3:University of Hyogo,4:Nagoya Univ.
Jun. 4	14:30 - 14:50 "The 2024 Noto Peninsula earthquake on Jan 1st 2024 caused a lot of building damage and landslides at Machino-machi, Wajima-City. We carried out active and passive surface wave methods and single station three-component microtremor measurements at the Machino-machi to delineate three-dimensional S-wave velocity (Vs) structure of the area. The surface wave methods yielded dispersion curves at two-sites and the single station three-component microtremor measurements yielded horizontal to vertical spectral ratio (H/V) at 50 sites. Peak frequencies of H/V ranged between 1 Hz and 7 Hz, and several sites along the Machino-river have particularly clear peak between 1 Hz and 3 Hz. We carried out the active and passive surface wave methods at the central part and eastern edge along the mountain of alluvial plain in Machi-machi. Dispersion curves from the two sites are clearly different. Phase velocity is approximately 100 m/sec at 6 Hz at the central part, whereas it is 200 m/sec at 10 Hz at the eastern edge along the mountain. Joint inversion estimated Vs profiles at two sites. Depth to a stiff layer with Vs of 200 m/sec is approximately 18 m and 6m deep at the central part and eastern edge along the mountain respectively."	10) Activ and passive surface wave methods and single station three-component microtremor measurements at Machino-machi Wajima City
		Kentaro Yamada・Gen Furuya(1),*Koichi Hayashi・Issei Doi・Gonghui Wang(2) 1:Toyama Prefectural University,2:DPRI Kyoto University
Jun. 4	14:50 - 15:10 "We conducted microtremor surveys in the northwestern adjacent area of Mt. Tsukuba for estimating near-surface 3-D S-wave velocity structure. Single-point microtremor measurements were conducted up to 355 points to calculate H/V spectral ratio (HVSR) curves. Surface topography of the surveyed area, about 6 km N to S and 6 km W to E, is basically flat but has a small stock of basement rocks cropping out in terrace sediments. The basement rocks are widely exposed on the northwestern flank of Mt. Tsukuba and were inferred to be buried underneath the terrace. As a result, characteristic HVSR curves having peaks in the relatively high-frequency zone were identified at the northwestern flank part but also at the surrounding zone of the basement rock stock. Making use of public boring database, we first built 1D Vs models of the points near the boring points. Next, we estimated 1D Vs models to all points based on the HVSR spectral patterns, stratigraphic and geomorphological information. Finally, we successfully reconstructed a dense 3D near surface Vs model of the area based on a deep neural network learning procedure."	11) Nearsurface 3D Vs modeling of the northwestern adjacent zone of Mt. Tsukuba from dense H/V measurement data.
		*Inazaki Tomio(1),Hayashi Koichi(2) 1:unaffiliated,2:DPRI, Kyoto Univ.
Jun. 4	15:10 - 15:30 "We conducted microtremor array explorations to estimate Rayleigh-wave phase velocities, and electrical explorations to measure apparent resistivity at the temporary strong-motion stations in Antakya for aftershocks of the 2023 Southeastern Turkey earthquake to investigate the strong ground motion characteristics. The SPAC method was applied to retrieve Rayleigh-wave phase velocities. Joint inversion of Rayleigh-wave phase velocity and apparent resistivity was used to reveal 1D shallow S-wave velocity structures. Most S-wave velocity profiles in Antakya have thin surface layers with S-wave velocities of around 200 m/s and thicknesses of less than 10 m. The depths to the top of the layers with S-wave velocities of above 450 m/s ranged from 10 to 20 m at most of the stations, and gradually increased toward the center of plain from hilly areas. The peak frequencies of the amplification factors, calculated from the profiles with S-wave velocities of below 600 m/s, were mainly concentrated in a high frequency range above 2.5 Hz. The deep part effects are important to explain the amplification effects in a low frequency range below 1.0 Hz in the damaged areas of Antakya."	12) Micrtremor Explorations in Affected Areas of the 2023 Southeastern Turkey Earthquake
		*Towa Ono・Hiroaki Yamanaka・Seiji Tsuno(1),Nobuo Takai(2),Masayuki Yoshimi(3),Hiroe Miyake(4),Kentaro Kasamatsu(5),Oguz Ozel(6),Ozgur Tuna Ozmen(7),Deniz Caka(8),Pinar Duran(6), et al. 1:Institute of Science Tokyo,2:Hokkaido Univ.,3:AIST,4:Tokyo Univ.,5:Kajima Technical Research Institute,6:Istanbul Univ.,7:AFAD,8:Kocaeli Univ.
Jun. 4	15:30 - 15:50 "The March 11, 2011 Tohoku-Pacific Ocean Earthquake caused serious localized building damage in Monou-cho, Ishinomaki City, Miyagi Prefecture. Past studies have indicated that seismic motions were likely amplified locally in this area due to differences in surface ground and subsurface structures. Therefore, in this study, we are conducting super dense seismic observations in Monou-cho in order to clarify the local changes in seismic motions. We installed seismometers in 40 sites. Observation period is about one year from June 2024 to June 2025. Using the observation data, we evaluated the site amplification characteristics and estimated the seismic motion of Tohoku-Pacific Ocean Earthquake of each observation point. The Fourier spectral ratios of seismic waves observed at each of the temporary station near the permanent station and other 39 temporary stations were obtained to evaluate site amplification characteristics of each station. The results show that relatively amplified frequency bands of seismic motion vary with observation points. The seismic motion of Tohoku-Pacific Ocean Earthquake of each observation point were estimated by multiplying the Fourier spectrum of waveform of Tohoku-Pacific Ocean Earthquake observed at the permanent station by the Fourier spectral ratio between the two stations"	13) Suer dense seismic observation and evaluation of site amplification characteristics in Monou-cho, Ishinomaki City, Miyagi Prefecture
		*Daichi Aoki・Hiroyuki Azuma(1),Toshiki Watanabe(2),Kazuya Shiraishi(3),Yoshiya Oda(1) 1:TMU,2:NU,3:JAMSTEC


June 04,2025　　Room No.2 (Room04, 2F)

Session	[Slope][Infrastructure Maintenance Management]
Chair	Keiichi Suzuki (Fukada Geological Institute)

Jun.4	10:10 - 10:30 "For the estimation of S-wave velocity structure model of the landslide area, we performed microtremor array measurement and estimated phase velocity dispersion curves at two landslide sites in Tokushima, Japan. At both sites, the microtremor amplitude and coherence was relatively low but peak appeared in H/V curves. We applied SPAC method but probably due to the effects of higher modes and low coherence, it was hard to select one dispersion curve, therefore possible several curves were used in inversion analysis and several models were estimated. These models are similar each other and good comparison with the S-wave velocity structure model of PS-logging. Especially all the models of near surface were almost same. We found low S-wave velocity layer at landslide site which was not found out of the landslide area."	24) S-wve velocity structure model estimated using array microtremor method at landslide sites, Tokushima, Japan
		*Kosuke Chimoto・Kento Fujii・Shuichi Hasegawa・Minoru Yamanaka・Atsuko Nonomura・Hiroyuki Araki(1),Masaki Ooku・Suzune Aono・TSUYUGUCHI KOJI (2) 1:Kagawa Univ.,2:YON-C
Jun.4	10:30 - 10:50 "To study the adaptability of microtremor exploration in landslide areas, We performed microtremor array measurement at two landslide sites in Shikoku, Japan. The array shape is an equilateral triangle. We applied the extended SPAC method to estimate the phase velocity dispersion curves. The estimated model shows an increase in S-wave velocity structure around 20 or 45 m depth, which is consistent with previous study. At both sites, the peak frequency of the H/V spectra appeared at 3Hz. The S-wave velocity structures estimated from H/V spectra and microtremor array measurements are similar. Some of the phase velocity dispersion curves are discontinuous, indicating that the ground may be heterogeneous. Microtremor array measurements suggested to be effective in landslide area."	25) A case study of microtremor exploration in landslide area in Shikoku
		*Ooku Masaki・Tsuyuguchi Koji・Aono Suzune(1),Hasegawa Shuichi・Yamanaka Minoru・Nonomura Atsuko・Araki Hiroyuki・Chimoto Kosuke(2),Ikeda Tatsunori(3),Nagata Tomohiro(4) 1:YONDEN CONSULTANTS co.,Inc,2:Kagawa University,3:Kyushu University,4:Naiba co.,Inc
Jun.4	10:50 - 11:10 "The subsurface resistivity depends on water saturation and electrical conductivity of pore water, and it becomes possible to pre-detection of slope failures by implementing resistivity monitoring in real-time using electrical resistivity surveys. In this study, long-term monitoring for early detection of slope failures using the electrical resistivity method was conducted. Additionally, a 1D forward modeling program specialized for the resistivity monitoring equipment is implemented, achieving improved calculation speed. Furthermore, a 1D inversion program using ART-RCG (ART: Alterable Resistivity and Thickness) method is newly implemented and found to be applicable as an inversion method for the resistivity monitoring. For future resistivity monitoring, it is necessary to simultaneously measure groundwater levels to evaluate the validity of the inversion results. It is also important to examine the analytical conditions in the inversion to achieve more accurate and faster analysis."	26) Long-term Monitoring for Early Detection of Slope Failure Using Electrical Exploration and Investigation of Data Analysis Methods
		*Yusuke Iwasaki(1),Toranosuke Miyamoto(2),Takumi Ueda(1),Daijiro Uehara・Kazuhiro Takeda(3) 1:Waseda Univ.,2:Graduate School, Waseda Univ.,3:CKC
Jun.4	11:10 - 11:30 "The drone electromagnetic survey was conducted in the vicinity of power lines and towers to investigate how the facilities affect the measurements. The results showed attenuation of received waveforms due to induced currents in overhead ground wires. These effects can be minimized by moving the grounded wire-type transmission source as far away from the power lines as possible or by using a loop-type transmission source. Although periodic waves associated with the power lines were also shown, it can be solved by stacking process. The waveform of a ground loop transmitter attenuates as it moves away from the transmitter source. Increasing the magnetic moment of the loop transmitter source is expected to improve the waveform. The application of two-plane flight measurements is also considered effective."	27) Influence of power lines on drone electromagnetic survey
		*Yohei Morifuji・Kenji Kubota(1),Akira Jomori(2),Genki Nakamura・Takumi Ueda(3) 1:CRIEPI,2:NEOSCIENCE,3:Waseda Univ.
Jun.4	11:30 - 11:50 "Drone-based airborne electromagnetic surveys have emerged as an effective method for small-scale investigations and shallow subsurface exploration compared to conventional helicopter-borne systems. This study examines data inversion techniques for drone-borne transient electromagnetic (TEM) systems with towed transmitter-receiver configurations. While nonlinear least squares methods are commonly used for ground/airborne TEM inversion, continuous data acquisition generates extensive datasets that challenge computational efficiency. Although deep learning (DL) approaches have shown potential for processing large airborne electromagnetic datasets, their application to drone-based surveys remains largely unexplored. Our research addresses this gap by performing one-dimensional inversions of actual drone TEM data using the Regularized Conjugate Gradient (RCG) method and various DL network models. We present a comparative analysis of these methods, evaluating their performance characteristics and result quality, thereby contributing to advancing processing methodologies for drone TEM surveys.	28) Application of Deep Learning Inversion for Time-Domain Airborne Electromagnetic Method Using UAVs
		Genki Nakamura・Tamaki Nishino(1),*Takumi Ueda(2),Yohei Morifuji・Kenji Kubota(3),Akira Jomori(4) 1:Graduate School, Waseda Univ.,2:Waseda Univ.,3:CRIEPI,4:NEOSCIENCE Co., Ltd.
Jun.4	11:50 - 12:10 "In Japan today, infrastructure facilities are aging, making infrastructure renewal urgent. Additionally, with the promotion of Digital Transformation (DX), integrating multiple information sources using Ge-ographic Information Systems (GIS) is becoming increasingly crucial in infrastructure development. Therefore, in this research, we aimed to enhance water pipe corrosion surveys using the very-low-frequency band alternating current (VLF-AC) electrical resistivity prospecting system devel-oped by the National Institute of Advanced Industrial Science and Technology (AIST). First, we examined high-efficiency continuous measurement with UGV towed VLF-AC through field experiments and nu-merical simulation results. It was demonstrated that subsurface structure estimation is possible with a single device traverse, and measurement data from curved survey lines can be utilized. Next, we worked on integrating exploration data with geographic information. As a result, it was shown that point data displays can retain exploration data for each measurement point, while texture mapping methods enable visualization of data across all depths."	29) High-Efficiency Continuous Measurement in Traction-Type VLF-AC Exploration and Integration of Exploration Data with Geographical Information System
		*Yume Kamiyama(1),Masayuki Ichikawa(2),Takumi Ueda(1),Motoharu Jinguji・Toshiyuki Yokota(3) 1:Waseda Univ.,2:Graduate School, Waseda Univ.,3:AIST


Session	[Geothermal Energy][Resource Exploration][Radioactive Waste]
Chair	Hiroshi Kisanuki(OYO)

Jun. 4	13:50 - 14:10 "In this study, we have investigated the inverse problem of Time-Domain Electromagnetic (TDEM) data, using a grounded wire source and a SQUID magnetometer. As regularized inversion methods, the RCG (Regularized Conjugate Gradient) method and the RRCG (Re-weighted Regularized Conjugate Gradient) method incorporating a weighting parameter have been adopted to compare stability and accuracy. We have conducted various numerical simulations of TDEM inversion with three-layer artificial resistivity models. The results showed that the RRCG method with a weighting parameter demonstrated high sensitivity to low-resistivity areas and provided better resistivity fitting at shallow depths com- pared to RCG inversion. Additionally, it was confirmed that the RRCG method can be applied to the analysis of field data targeting geothermal resources."	30) Application and Evaluation of Regularized Conjugate Gradient Inversion (RCG and RRCG Methods) for Time-Domain Electromagnetic Data using Grounded Wire Source
		*Kazuki Mitsui(1),Shintaro Yuki(2),Takumi Ueda(1) 1:Waseda Univ.,2:Graduate School, Waseda Univ.
Jun. 4	14:10 - 14:30 "In geothermal reservoir exploration, it is important to estimate the location of highly productive fractures. Electromagnetic exploration has the potential to do this, and resistivity distribution can be used to estimate the area where open fractures are concentrated (Dens fracture zone) within the geothermal reservoir under cap rock. In this study, we used data from previous research on the relationship between fluid temperature and resistivity (Kummerow and Raab, 2015) to examine the method of estimating rock resistivity using Archie's equation for appropriate modeling of geothermal reservoirs. From this, we confirmed that the resistivity of rocks in geothermal reservoirs depends on porosity, temperature, and fluid properties, and found that the effect of porosity is greater than that of temperature. Using the resistivity model created from this relationship, we evaluated the resistivity anomaly due to “Dens fracture zone” from the apparent resistivity of the 3D modeling results of the MT method, and also discussed the possibility of monitoring."	31) Reistivity Model and MT Response in Geothermal Reservoirs
		*Hideaki Ban・Toshiaki Tanaka・Hideki Mizunaga(1) 1:Kyushu University
Jun. 4	14:30 - 14:50 "This study focuses on developing a new potential electrode for measuring electric fields in the Magnetotelluric (MT) method. Conventional non-polarizing electrodes, such as lead-lead chloride, require maintenance and are prone to degradation over time. The study evaluated the stability, noise characteristics, and durability of different materials under different conditions, including iron, stainless steel, conductive resin, and titanium. Both laboratory and field experiments demonstrated that conductive resin and titanium electrodes have the potential to perform similarly to conventional lead-lead chloride electrodes concerning electric field measurements in the MT method. The results suggest that these new materials are promising candidates for long-term monitoring in MT surveys."	32) Fundamental Study on the Development of a New Potential Electrode for the MT Method
		*Toshiaki Tanaka・Hiroyuki Furukawa・Hideki Mizunaga・Koji Hashimoto(1) 1:Kyushu Univ.
Jun. 4	14:50 - 15:10 "Electromagnetic (EM) methods have been widely accepted for the investigation of various geological formations for many purposes, including “geological disposal”. However, the application of EM methods for potential disposal sites, particularly in coastal areas, can be challenging for both data acquisition and analysis due to artificial EM noise from human activities.	33) Field Application and Data Analysis of TDEM Method in Densely Populated Areas for Groundwater Structure Investigation in Coastal Regions
		*Hana Momozu・Takumi Ueda(1),Hidehiko Watanabe・Hidehiro Ishikawa(2),Reo Ikawa(3) 1:Waseda Univ.,2:MINDECO,3:AIST


June 04,2025　　Core Time: Room05, 2F, Exhibition: Room03, 2F

Session	[Poster Sessions: Core Time]
Chair	Toshiaki Tanaka (Kyushu University)

Jun. 4	16:10 - 17:50 "In this study, we investigated whether DC resistivity survey can be applied to visualizing internal human anatomical structures, especially for fracture diagnosis. A similar technique, known as Electrical Impedance Tomography (EIT), is already being used in the medical science. The EIT can visualize internal human structures by applying a weak electrical current to the body's surface and mapping the resistivity distribution, primarily targeting tissues like the lungs and fat since they have higher resistivity than other tissues. However, EIT suffers from low resolution in deep tissues, and the movements of the electrode positions by the expansion and contraction of highly deformable organs like the lungs; therefore, the application of EIT in clinical diagnosis has not yet become widespread both domestically and internationally. Here, we focused on the possibility of determining fracture healing based on temporal changes in resistivity structure of the arms/legs. We performed the electrical resistivity tomography on the surface of a human simulating sample, and found the possibility of detecting the temporal changes at the fractured bone from the resistivity distributions just after fracturing and after the healing of fractures."	P-1) Application of Electrical Resistivity Tomography in Medicine -Fundamental Experiments for Fracture Diagnosis -
		*Yuki Oshima・Tadanori Goto(1) 1:University of Hyogo
Jun. 4	16:10 - 17:50 "We have conducted the building damage investigation and microtremor array surveys in Mashima, Sakaemachi and Kitaomachi, Himi City, Toyama Prefecture, following the Noto Peninsula earthquake of January 1, 2024. The damage assessment was conducted by five persons, and the final judgment was made while revising the judgment criteria, which revealed localized damages. Microtremor array surveys were also conducted and the S-wave velocity structure was estimated at 19 points, which showed a relationship with the results of the damage assessment. Furthermore, the liquefaction potential index, PL was calculated using estimated S-wave velocity structure. The calculated PL values in the study area are generally high tending to be higher on the north side, although some points showed low values. It is possible that liquefaction was dominant in the damage throughout the study area, while there is an area where strong ground motions could be the cause of the severe damages."	P-2) Building damage and subsurface structure in Mashima, Sakaemachi and Kitaomachi, Himi City during the 2024 Noto Peninsula Earthquake
		Souma Kanayama・Yugo Sato(1),Michio Miyano・Eisuke Ikuta(2),Tsutomu Ochiai・Takahisa Enomoto・Yoshiharu Shumuta(3),Nobuhiro Hasegawa(4),Hiroyuki Azuma・*Yoshiya Oda(1) 1:TMU,2:OMU,3:KU,4:TDU
Jun. 4	16:10 - 17:50 "During the 2024 Noto Peninsula earthquake (Mw7.5), strong ground motions and significant crustal deformation were observed in the northern part of the Noto Peninsula. We carried out microtremor array surveys around KiK-net Togi (ISKH04; ISKH04 array) and K-NET Wajima (ISK003, WJM array). Phase velocities were obtained in the frequency range of 0.4--6 Hz at Togi and 0.7--3.4 Hz at Wajima. Comparison between the observed and the theoretical phase velocities shows reasonable agreement at Togi, but further improvement of the model is needed. At Wajima, Horikawa et al. (2010) model agrees well, but slight differences at higher frequencies ($>$ 1 Hz). Displacement waveforms calculated from the three KiK-net and one JMA acceleration records indicated significant crustal deformation correlated with that estimated by GNSS or InSAR."	P-3) Strong Ground Motion Characteristics and Microtremor Survey at Togi, Shika Town, and Wajima City in the Noto Peninsula
		*Kunikazu Yoshida・Fumika Sato・Noa Nagatsuma(1),Kazuhiro Somei(2),Susumu Kurahashi(3) 1:University of Fukui,2:Geo-Research Institute,3:Aichi Institute of Technology
Jun. 4	16:10 - 17:50 "The accuracy of determining the propagation velocity of electromagnetic wave is an important subject for ground-penetrating radar (GPR) in recent civil engineering field. Therefore, we numerically evaluated the effects of basic analytical procedures to estimate velocity and depth. Zero-offset processing is unnecessary in general analysis, but it is effective in improving depth accuracy. The estimation accuracy of the three types of velocity analysis methods is sufficiently high, and the main estimation error is due to other factors, for example the choice of events for analysis. The input velocity for the migration processing should be higher than the actual propagation velocity in normal situations."	P-4) A study on improvement of the analysis procedures of ground-penetrating radar based on wave propagation analysis in subsurface ground
		*Kyosuke Onishi・Takuya Ueda(1) 1:PWRI
Jun. 4	16:10 - 17:50 "In order to evaluate for the effectiveness of an environmentally friendly seismic source using underwater speaker as a permanent seafloor seismic source, we conducted a vibration experiment using an underwater speaker and DAS observation system in the 3000m-class deep observation well. As a result, we confirmed that direct waves could reach a depth of approximately 640 m."	P-5) Underwater speaker oscillation experiment for "development of a permanent seafloor seismic source"
		Yasuhiro Asai(1),Hitoshi Tsukahara(2),*Tomokazu Kurihara・Takuya Maeda・Tsutomu Yamate・Toru Kuroda(3),Tetsuro Tsuru(4),Fumitoshi Murakami(2),Minoru Yoshida(3) 1:Tokyo Power Technology Ltd.,2:JGI, Inc.,3:Hakusan Corporation,4:Shonan Institute of Geology & Geophysics


June 05,2025　　Room No.1 (Room05, 2F)

Session	Executive Sessions
Chair	Koichi Hayashi, Tetsuya Kogure (Kyoto University)

Jun. 5	13:30～13:40	Explanation of aim

Jun. 5	13:40～14:40	Atsushi Yashima (Gifu University)

Jun. 5	14:40～15:40	Minoru Yamanaka (Kagawa University)


Session	Special Sessions
Chair	Koichi Hayashi, Tetsuya Kogure (Kyoto University)

Jun. 5	16:00 - 16:20 "Identifying the depth and geometry of the slip surface is crucial when designing countermeasures for landslides. However, in highly active landslide blocks where geological drilling cannot be conducted, direct confirmation of the slip surface is not feasible. In this study, microtremor array measurements and surface wave methods were performed both inside and outside the landslide block to attempt to delineate the boundary between the moving landslide mass and the stable bedrock. As a result, clear phase velocity changes in the dispersion curves were observed at several measurement locations within the landslide block. Nevertheless, it was not possible to clearly differentiate the S-wave velocities between the moving landslide mass and the slopes outside the block. Further detailed analysis is required to achieve more definitive characterization."	101) Expectations of geophysical exploration for landslide control design.
		*Hayato Ishida(1) 1:Nippon Koei Co., Ltd.
Jun. 5	16:20 - 16:40 "The authors previously examined the potential frequency dependence of subsurface electric current flow, which may be influenced by cracks, voids, and underground moisture. This frequency-dependent behaviour can be attributed to the displacement current term (i.e., the permittivity term) in Maxwell’s equations. Therefore, inverting measurement data to estimate variations in permittivity enables subsurface evaluation using physical properties beyond conventional resistivity. This approach is expected to provide new insights, particularly in the study of groundwater behaviour. In the present study, this method was applied to areas vulnerable to landslides and slope failures. Geological and groundwater conditions were interpreted using existing data in conjunction with resistivity and permittivity measurements."	102) Analysis of Frequency-Dependent Effects (Displacement Current Term) in Drone-Based Airborne Electromagnetic Survey and Geological and Groundwater Interpretation – Application to Landslide Areas –
		*Akira Jomori・Tetsuya Toyama(1),Kentaro Kanayama(2),Atsuko Nonomura(3),Atsuhiko Kinoshita(4) 1:Neo Science,2:Dia Nippon Engineering Consultants,3:Kagawa Univ.,4:MLIT
Jun. 5	16:40 - 17:00 "This study reports the results of slope-deformation monitoring with distributed fiber optic sensing. Considering that slope disasters are closely related to the presence of water, it is important to elucidate the relationship between the changes in groundwater level and strain change. The changes in groundwater level can be detected as temperature changes during the active heating method, which is achieved by heating a metallic wire installed in a borehole. We adopted the phase-noise compensated optical frequency domain reflectometry (PNC-OFDR) method, whose data acquisition time is several milliseconds. A laboratory test confirmed the effectiveness of the PNC-OFDR method. It successfully detected the location of high saturation zones on the surface of a mortal specimen with a diameter of 77 mm and length of 2,000 mm, showing possible application to slope-deformation monitoring in a mountain. Then, fiber optic cables have been installed into a 50 m-deep borehole together with a heating cable. Data has now been analyzed to understand the slope deformation process."	103) Monitoring slope deformation based on the measurements of temperature and strain changes with fiber optic sensing
		*Tetsuya Kogure(1),Ashis Acharya・Daiki Tanimura・Chao Zhang・Fumihiko Ito(2),Toshihiro Sakaki(3),Mitsuru Komatsu(4),Issei Doi(1) 1:DPRI, Kyoto Univ.,2:Shimane Univ.,3:ESE Consulting,4:Okayama Univ.
Jun. 5	17:00 - 17:20 "Microtremor array measurements were conducted on a slope next to the location where the rainfall-induced landslide occurred in the past. Fifteen receivers were deployed every 2 m along the slope, and we observed ambient noise for 15 to 20 minutes. The observed data were analyzed using the CMP-SPAC method. The maximum receiver spacing for the data analysis was limited to 20 m to maintain a high spatial resolution. Inverse analysis by the non-linear least square method was carried out to obtain S-wave velocity profile at every 4 m interval, and a two-dimensional S-wave velocity profile was obtained. The result indicates lower velocity zones at some distances corresponding to the weathered layer, confirmed by sounding tests. The S-wave velocity profile estimated by a linear array might be deviated from actual S-wave velocity if the ambient noise comes from only specific directions. However, we can detect low-velocity zones along the slope, and it is acceptable to find weak locations for mitigating landslide damages."	104) Microtremor array measurements on a slope of landslide area
		*Chisato Konishi・Masao Nemoto(1) 1:OYO


June 06,2025　　Room No.1 (Room05, 2F)

Session	[CO2_1][Earthquake2][Disaster Prevention2]
Chair	Kosuke Chimoto (Kagawa University)

Jun. 6	9:00 - 9:20 "Cosmic-ray muography enables non-invasive imaging of internal density structures, with laboratory-scale experiments gaining attention for validating new applications. However, muon count rates are susceptible to meteorological variations, limiting measurement accuracy. To address this, we implemented a reference measurement system comprising two identical muon detectors: one measuring the target material and the other recording background cosmic-ray flux. By normalizing target measurements against the background, we achieved substantial improvement in data reliability. We evaluated this method by measuring an acrylic target with varying thicknesses (20?80 cm) and an aluminum cube. Bayesian estimation was applied to the transmission data for density evaluation. The estimated density for aluminum was 2.713 ± 0.454 g/cm?, closely matching the true value of 2.700 g/cm?, with an error of only 0.5%. Our results demonstrate that incorporating reference measurements effectively mitigates environmental influences, enhancing the precision of laboratory muography experiments. This approach lays the groundwork for future applications, including borehole muography for carbon capture and storage (CCS) monitoring, where accurate density measurements are critical for assessing subsurface changes."	14) High-Accuracy Optimization of Laboratory Muography Experiments through Reference Measurements
		Hamid Basiri(1),Masashi Kodama(2),*Jun Matsushima(1),Toshiyuki Yokota(2),Mohammed Y. 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
Jun. 6	9:20 - 9:40 "In recent years, climate change and extreme weather have caused significant damage to human societies and ecosystems, prompting an international movement to regulate emissions of major greenhouse gases such as image.png (carbon dioxide). However, since fossil fuels remain the primary energy source in present, achieving a rapid reduction in image.png emissions remains a major challenge. Carbon dioxide Capture and Storage (CCS) is a technology designed to separate and store image.png underground. In CCS, monitoring image.png behavior using geophysical exploration plays a crucial role, as well as drilling and injection processes. Full Waveform Inversion (FWI) is one of the relatively recent seismic imaging techniques for CCS monitoring, which enables high-resolution subsurface imaging by utilizing full waveform datasets for analysis. In this study, we first implemented Time-Domain FWI codes using the adjoint state method. Then, we performed numerical analyses using velocity models that simulate CCS monitoring scenarios to assess the effectiveness of FWI in detecting velocity reductions associated with image.png. The results showed that FWI captured approximately 50-70% of the actual velocity decrease, regardless of its magnitude."	15) Time-Domain FWI numerical simulation on the detection rate of velocity decrease for CCS models
		*Kento Kamimura(1),Shohei Minato・Toshiyuki Yokota・Masashi Kodama(2),Takumi Ueda(3) 1:Grad School of Waseda Univ.,2:AIST,3:Waseda Univ.
Jun. 6	9:40 - 10:00 "Kozushima Island, a volcanic island located in Tokyo, is one of the 51 active volcanoes designated by JMA for continues monitoring to prevent volcanic disasters. In historical times, the region has experienced several earthquake swarms, including a notable one in 2000 triggered by the eruption of Miyakejima Island. This event was accompanied by crustal deformation and magma dike intrusions. As a result, previous studies have attempted to estimate the subsurface structure, suggesting the possible existence of a magmatic body beneath Kozushima Island and a relationship between magmatism and seismicity. In this study, we estimated the three-dimensional velocity structure beneath Kozushima Island by Double-Difference Tomography method with dense seismic observation data collected from October 2020 to March 2021. The aim was to reassess the possibility of a subsurface magmatic body and to contribute additional insights for volcanic disaster prevention. The tomography results allowed us to image the velocity structure down to depths of approximately 8km. At depths from 0 to 8km directly beneath Kozushima Island, a vertical low-Vp zone was detected, however, the Vp/Vs ratio in this area was also low. Therefore, we conclude that our results do not support the presence of a magmatic body beneath Kozushima Island."	16) Three-dimensional velocity structure beneath Kozushima Island, estimated by Double-Difference Tomography method with dense seismic observation data
		*Jiro Nakajima・Adrianto Widi Kusumo・Hiroyuki Azuma・Yoshiya Oda(1) 1:TMU
Jun. 6	10:00 - 10:20 "We have conducted seismic surveys throughout the Nankai Trough to reveal the geological structure of the seismogenic zone. The eastern Nankai Trough is the area where the 1944 Tonankai Earthquake occurred, and slow earthquakes occurred repeatedly in the shallow part of the trench side. In addition, the detailed shape and spatial continuity of the subducting Paleo-Zenisu Ridge were unclear. We conducted intensive seismic reflection surveys with R/V KAIMEI along dense survey lines in 2022?2024 to investigate the basement topography on the subducting plate and the internal structures in the overriding plate from offshore Kumano-nada to offshore Enshu-nada. The results suggest that the Paleo-Zenisu Ridge may extend farther west than previously inferred. The characteristics of fault distribution in the accretionary complex and the southern part of the Kumano forearc basin, which have been affected by significant topographic undulations of the subducting basement, are clarified."	17) Dense seismic survey of crustal structure in the Eastern Nankai Trough
		*Kazuya Shiraishi・Ryuta Arai・Ryo Miura・Tetsuo No・Yasuyuki Nakamura・Gou Fujie・Seiichi Miura(1) 1:JAMSTEC
Jun. 6	10:20 - 10:40 "The penetrator developed in the LUNAR-A project has continued to be improved to extend its observation range from “possible” to “ wanted” observation areas in extreme environments such as volcanoes and Antarctica after the cancellation of the project. The penetrator itself functions as an observation probe, and can be penetrated into the ground by a drone to set up an observation site. This study introduces the concept and applications of penetrators as a geophysical exploration tool in extreme environments. As a case study, we introduce the observational results obtained during the Japanese Antarctic Research Expedition (JARE) 64th to 66th. These observations provided positioning data of glacier flow as well as seismic and infrasound data associated with ice quakes. Based on the results from the geodetic penetrator deployed at Shirase Glacier, Antarctica, we discuss the mechanical components and mechanisms necessary to ensure stable observations using penetrators in future applications."	18) Penetrator-Based Glacier Flow Positioning and Future Mechanical Design Considerations
		*Kodai Yamamoto(1),Masa-yuki Yamamoto・Yasuhiro Nishikawa・Takamasa Hiratsuka(2),Kazuto Saiki・Ryota Taniguchi(3),Satoshi Tanaka(4) 1:Kochi University of Technolog(KUT),2:KUT,3:Ritsumeikan University,4:JAXA


Session	[CO2_2][Methane Hydrate]
Chair	Kazuya Shiraishi (JAMSTEC)

Jun. 6	11:00 - 11:20 "DAS-VSP is widely used as an efficient method for monitoring injected CO2 behavior in CCS projects. While permanently installing fiber optic cables behind casing provides optimal data quality and repeatability, practical constraints often prevent this installation approach in field settings. To address this limitation and optimize CCS monitoring, we conducted a two-year experimental study using the wireline method for DAS-VSP data acquisition and obtained time-lapse datasets. The results showed that DAS-VSP data, acquired in stable downhole environments isolated from the near-surface weathering effects, showed high repeatability in both field records and imaging results even with the wireline method, demonstrating the effectiveness of wireline DAS-VSP monitoring"	19) Time-lapse data acquisition experiment using wireline DAS-VSP
		*Yuki Imai・Takao Nibe(1),Masafumi Katou(2) 1:JAPEX,2:JGI, Inc.
Jun. 6	11:20 - 11:40 "In monitoring methods for CO? geological storage projects, it is essential to employ techniques capable of detecting decreases in seismic velocity within the reservoir caused by CO? injection. In particular, the area surrounding the injection well has been recognized as a high-risk zone for CO? leakage pathways and therefore requires more frequent evaluation. This study focused on 3D travel-time tomography using DAS-VSP and evaluated its applicability through the acquisition and analysis of field data at a test site, as well as numerical simulations. The analysis using only VSP data successfully estimated a 3D P-wave velocity structure that was generally consistent with known geological features and also detected low-velocity zones associated with a reversed velocity gradient. Moreover, numerical simulations assuming temporal velocity reduction also confirmed the ability to reproduce the velocity reduction zones. These results indicate that 3D travel-time tomography using DAS-VSP shows great potential as a CO? monitoring technique capable of detecting reductions in seismic velocity in regions near wells."	20) A Study on 3D Travel-Time Tomography Using DAS-VSP for CO₂ Monitoring
		*Rei Sato・Ryunosuke Kikuchi (1),Shinya Asakawa・Norifumi Narita・Hiroyuki Takaoka(2) 1:4D GeoTek,2:Dia Nippon Engineering Consultants
Jun. 6	11:40 - 12:00 "A scenario revealing the occurrence, growth, and disappearance of shallow methane hydrate in three different areas (off-Joetsu, off-Tango Peninsula, and off-Sakata) along eastern margin of Sea of Japan was constructed, based on high-resolution acoustic investigation. Despite the geological characteristics of the three areas are seemingly different each other, the rise and fall scenario of the shallow methane hydrate in a shallow subseafloor suggests consensus through the different characteristics, by dividing individual cases: it is considered that tectonic faults play an important role in transporting methane-bearing fluids from deep to shallow areas, these fluids contribute to grow methane hydrate at the shallow subseafloor, and the methane hydrate could be dissociated and flow out below the seafloor and then yield pockmark on seafloor."	21) A formation and dissociation scenario of shallow methane hydrate: Examples from off-Sakata, off-Joetsu, and off-Tango Peninsula, along eastern margin of the Sea of Japan
		*Miho Asada・Ayumu Miyakawa(1) 1:AIST
Jun. 6	12:00 - 12:20 "Comprehensive seismic reflection surveys were conducted in areas containing shallow methane hydrate using multiple scale acquisition methods: conventional two-dimensional seismic, high-resolution three-dimensional seismic, deep towed seismic, and Ocean Bottom Node (OBN) seismic survey. These surveys enhanced our understanding of shallow methane hydrates accumulation and formation mechanisms. Our study adopted a multi-scale approach using three seismic sources with distinct effective frequency bands: large Airgun (4-150 Hz), GI-Gun (4-300 Hz), and Sub-Bottom-Profiler (500-2,400 Hz). This survey strategy enabled unprecedented visualization of subsurface structures across scales ranging from centimeters to kilometers. Here, we present the detailed data acquisition parameters, survey equipment configurations, and seismic records obtained through each survey method. This integrated approach is expected to provide valuable insights into the distribution and characteristics of shallow methane hydrates."	22) Multi-scale seismic methods applied in a shallow methane hydrate field (Part 1: data acquisition)
		Shutaro Satio・Osamu Iobe・Yousuke Teranishi・Norio Sato・Kengo Aoki・Fumitoshi Murakami・*Kenichi Akama(1),Toshiyuki Yokota・Kazuo Yaguchi・Manabu Tnahashi(2), et al. 1:JGI, Inc.,2:AIST
Jun. 6	12:20 - 12:40 "Comprehensive seismic reflection surveys were conducted in areas containing shallow methane hydrate using multiple scale acquisition methods: conventional two-dimensional seismic, high-resolution three-dimensional seismic, deep towed seismic, and Ocean Bottom Node (OBN) seismic survey. These surveys enhanced our understanding of shallow methane hydrates accumulation and formation mechanisms. Our study adopted a multi-scale approach combining three seismic sources with distinct effective frequency bands: Large Airgun (4-150 Hz), GI-Gun (4-300 Hz), and Sub-Bottom-Profiler (500-2,400 Hz). This survey strategy enabled unprecedented visualization of subsurface structures across scales ranging from centimeters to kilometers. Here, we report on the data processing specifications for various exploration methods and the processing elements that contributed to improved imaging quality. By comparing imaging results from each method, we evaluate their effectiveness."	23) Multi-scale seismic methods applied in a shallow methane hydrate field (Part 2: data processing)
		Yousuke Teranishi・Shutaro Saito・Osamu Iobe・*Kenichi Akama(1),Toshiyuki Yokota・Kazuo Yamaguchi・Manabu Tnahashi・Masashi Kodama・Shohei Minato(2) 1:JGI, Inc.,2:AIST


June 06,2025　　Room No.2 (Room04, 2F)

Session	[Buried Object][Ground Water][Civil Engineering2]
Chair	Kyosuke Onishi (PWRI)

Jun. 6	9:00 - 9:20 "We developed a new algorithm for a dual sensor that combines GPR and metal detector. The dual sensor we developed solves the problem of false signals caused by radar clutter, which is a problem in GPR, by applying migration to the GPR signal for reconstructing 3D images and displaying them in a C-scan. We found that this approach can reduce the clutter. This was achieved by creating a system that can obtain location information even though it is hand-scanned manually. Deminers can observe the horizontal shape of the objects on the C-scan. The dual sensor we developed is in operation for humanitarian demining in landmine-affected countries including Ukraine and Cambodia."	34) Humanitarian Demining in Ukraine by Dual Sensor
		*Motoyuki Sato・Ryuma Sito(1)
Jun. 6	9:20 - 9:40 "To estimate buried object shapes from Ground-Penetrating-Radar (GPR) data, we defined reflection image shapes from three representative types of buried structures (single circular cross-section, single rectangular cross-section, and multiple circular cross-sections) as object reflection models. The model accuracy was evaluated based on the fitting score using the data generated by electromagnetic wave simulations. We performed model fitting on experimentally obtained radar data using the nonlinear least squares method and verified the identification of buried object shapes based on the coefficient of determination. By applying a pre-estimation method for initial parameters to enhance convergence during fitting, we confirmed a classification accuracy of 100% (2/2) for single circular cross-section structures and 67% (2/3) for single rectangular cross-section structures."	35) Estimation of Buried Object Shapes using Ground Penetrating Radar
		*Ryotaro Kawahara・Atsushi Isobe・Ai Kiriyama・Tadashi Okumura・Takashi Kawamoto(1) 1:Hitachi, Ltd.
Jun. 6	9:40 - 10:00 "To estimate 3D underground objects from ground-penetrating radar (GPR) surveys, we propose a technique for identifying reflection images originating from the same buried object. Our method extracts reflection images from GPR data, then inputs them into a neural network-based feature extraction model to calculate feature vectors. Extracted features are clustered by applying k-means algorithm. The proposed method was validated using simulation data that contains two types of buried pipes. As a result, 85% (171/200) of the reflection images were correctly identified. Furthermore, identification performance improved to 92% (185/200) when a mask corresponding to the shape of the reflection image was applied prior to feature extraction. In addition, we conducted tests using experimental data that included three types of buried objects. The accuracy rate of the proposed method was 75% (6/8), and we confirmed that this accuracy can be further improved by fine-tuning the feature extraction model."	36) Identification of Buried Objects using Feature Extraction Model for Ground Penetrating Radar
		*Ai Kiriyama・Ryotaro Kawahara・Tadashi Okumura・Atsushi Isobe・Takashi Kawamoto(1) 1:Hitachi, Ltd.
Jun. 6	10:00 - 10:20 "It is possible to estimate the distribution of the volumetric water content of the soil, which is highly correlated with the relative permittivity of the soil, by obtaining the electromagnetic wave velocity structure of the soil layer from the received waveform data of ground-penetrating radar. To obtain high-resolution relative permittivity distributions, full-waveform inversion is required. However, full-waveform inversion is computationally intensive in the numerical analysis part and requires spatially dense data. Therefore, the object of this study is to predict electromagnetic wave propagation and relative permittivity distribution in soils from received waveform data on the surface and sides of the soil layer by using physics-informed neural networks for full-waveform inversion. In this study, we used full-waveform inversion to obtain the relative permittivity distribution of two layers in soils for the electromagnetic wave propagation of 1 GHz pulse waveforms in TM mode emitted from a point source located on the surface."	37) Application of physics-informed neural networks for full-waveform inversion of ground-penetrating radar data
		*Koki Oikawa(1),(2)・Hirotaka Saito(1) 1:TUAT,2:JSPS
Jun. 6	10:20 - 10:40 "The road collapse accident that occurred in Yashio City, Saitama Prefecture, has become a social problem. In order to prevent road collapses, ground penetrating radar (GPR) has been used to detect cavities under the road surface. Considering that the depth of the sewage pipe where the collapse occurred is 10 m, the depth that can be detected by GPR is shallow, about 1 to 2 m, and it is necessary to improve the detection depth by GPR. However, is it possible to detect 10 m deep with GPR ? To achieve this, it is necessary to consider the hardware function of the GPR and the attenuation characteristics of radio waves in underground. However, expectations for the detectable depth are increasing without sufficient discussion of these issues. In this paper, the feasibility of detecting 10 m deep are considered, focusing mainly on the attenuation characteristics of radio waves in underground."	38) Considerations on radio wave attenuation in ground penetration radar
		*Keiichi Suzuki(1) 1:Fukada Geological Institute


Session	[Earthquake3][Disaster Prevention3][Other]
Chair	Chisato Konishi (OYO)

Jun. 6	11:00 - 11:20 "Artificial Neural Networks (ANNs) were applied to an inversion of a phase-velocity dispersion curve to estimate an S-wave Velocity (Vs) structure. A new ANN was developed with smooth transitional weights from the input neurons of the phase velocities at neighbor frequencies. We trained the smoothed ANNs using synthetic Rayleigh wave phase velocities for randomly generated three-layered models. Using unseen test datasets, we found that the smoothed ANN has the ability to approximate the true Vs profiles with a misfit of less than 10%. Using synthetic test dispersion curves with different Gaussian noises, we observed that the smoothed ANN is more robust against high-amplitude noises than the conventional ANN. The smoothed ANN was applied to actual dispersion curves observed at three sites in the Nile Delta, Egypt. Good agreement is detected between the observed dispersion curves and the calculated curves for shallow Vs profiles estimated in the smoothed ANN."	39) Phase Velocity Inversion using Artificial Neural Networks with Smoothing Constraint for Shallow Shear Wave Velocity Profiling
		*Mohamed Maklad(1),Hiroaki Yamanaka・Seiji Tsuno(2) 1:Science Tokyo,NRIAG,2:Science Tokyo
Jun. 6	11:20 - 11:40 "Surveillance systems using cameras have been widely deployed. However, they suffer from limitations such as privacy concerns, blind spots, and reduced detection accuracy during nighttime or under bad weather conditions. Monitoring with seismometers is one of the methods that can solve the problems of vision-based systems. In this study, we investigated the feasibility of using seismic data to classify and track moving objects (vehicles and pedestrians) for security applications. A Convolutional Neural Network (CNN) applied to spectrograms achieved a classification accuracy of 92.6%, and false detections were significantly reduced through post-processing. Moreover, epicenter detection using cross-correlation between multiple seismometers demonstrated tracking regardless of whether the source was located inside or outside the seismometer array. The combined processing time for classification and epicenter detection was approximately 0.08 seconds per 5-second data segment, confirming the feasibility of real-time application for security purposes."	40) Detection, Classification and Tracking of Moving Objects Using Vibration Data Analysis and AI
		*Yuki Oi・Takeshi Tsuji・Ahmad Bahaa Ahmad(1),Masatoshi Nomura・Ryota Nomura(2) 1:Tokyo Univ.,2:Wavelet, Inc.
Jun. 6	11:40 - 12:00 "Earthquake damage can be highly localized, necessitating detailed seismic observations; however, constructing such dense networks is often impractical due to high costs and logistical constraints. This study introduces DeepONet, a machine learning approach that predicts seismic waveforms at arbitrary locations using only limited reference data. DeepONet effectively captures spatial distributions by utilizing branch network inputs formatted as 2D images, allowing it to represent complex spatial patterns efficiently. Numerical experiments using synthetic models demonstrate that even under challenging subsurface conditions, the method delivers accurate waveform predictions. These promising results suggest that DeepONet could be a valuable tool for enhancing seismic hazard assessment and improving our understanding of earthquake dynamics."	41) An attempt to predict earthquake waveforms using machine learning
		*Matsuoka Toshifumi(1),Azuma Hiroyuki・Oda Yoshiya(2) 1:Fukada Geological Inst.,2:Tokyo Metropolitan Univ.
Jun. 6	12:00 - 12:20 "This study aims to reconstruct the seismic motion of past damaging earthquakes at high spatial resolution and to compare the results with localized damage patterns. To achieve this, we integrate ultra-dense temporary seismic observations with machine learning techniques in areas that have previously experienced localized damage. An ultra-high-density seismic observation has been conducted in Ishinomaki City, Miyagi Prefecture. Based on records from a limited number of reference observation points, the ground motion at other observation points was predicted using a machine learning model. The model was trained on both observed earthquake data and synthetically generated data produced via data augmentation. Using the trained model, seismic motion was predicted at all other observation points under two conditions: one utilizing three reference stations, and the other utilizing a single station. The predicted waveforms were then compared against actual measurements. The results demonstrated good agreement, with correlation coefficients of 0.77 and 0.65 for the three- and one-point cases, respectively.	42) Development of Virtual Seismic Network using machine learning　- A method of setting up an AI model for each observation point -
		*Hiroyuki Azuma・Shota Nonaka・Koki Tanimura(1),Toshiki Watanabe(2),Kazuya Shiraishi(3),Yoshiya Oda(1) 1:TMU,2:Nagoya Univ.,3:JAMSTEC

VENUE
	BLDG.63, 2F,NISHIWASEDA CAMPUS, 3-4-1 Okubo, Shinjuku-ku, TOKYO, JAPAN

SCHEDULE
	Wednesday, June 4, 2025
		Openning Speech	Room No.1 (Meeting Room 05, 2F)	10:00-10:05
		__Speaker:	Jun MATSUSHIMA (Univ. of Tokyo, GSFS; President of SEGJ)
		Technical Sessions	Room No.1 (Meeting Room 05, 2F)	10:10-15:50
		Technical Sessions	Room No.2 (Meeting Room 04, 2F)	10:10-15:10
		Poster Core Time	Room No.1 (Meeting Room 05, 2F)	16:10-17:50
		Exhibition	Room No.3 (Meeting Room 03, 2F)	11:00-17:50

	Thursday, June 5, 2025
		General Meeting	Room No.1 (Meeting Room 05, 2F)	10:00-11:40
		Executive Sessions	Room No.1 (Meeting Room 05, 2F)	13:30-15:40
		__Chair:	Koichi HAYASHI & Tetsuya KOGURE (Kyoto University)
		__Presentation(1):	Expectations for Geophysical Surveys in SHM (Structural Health Monitoring) of Road Earthwork Structures Atsushi YASHIMA (Gifu University)
		__Presentation(2):	Application of Geophysical Exploration in the Evaluation of Stability of Castle Stone Walls - Focusing on Failed Cases Minoru YAMANAKA (Kagawa University)
		Special Sessions	Room No.1 (Meeting Room 05, 2F)	16:00-17:20
		Banquet	Cafeteria (BLDG.63, 1F)	17:45-19:45
		Exhibition	Room No.3 (Meeting Room 03, 2F)	09:30-17:00
	Friday, June 6, 2025
		Technical Sessions	Room No.1 (Meeting Room 05, 2F)	09:00-12:40
		Technical Sessions	Room No.2 (Meeting Room 04, 2F)	09:00-12:20
		Exhibition	Room No.3 (Meeting Room 03, 2F)	09:00-12:00

Registered and Paid		Pre-Registration (until May 13, 2025)	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 5,500-**	JPY 6,600-**
Conference Meeting	Student	JPY 3,300-**	JPY 3,300-**

LIST OF EXHIBITORS
	ACT Electronics Corp. Geofive Co.,Ltd. Hakusan Corporation Cosmos Shoji Co., Ltd.

LIST OF ADVERTISEMENTS
	Geophysical Surveying Co., Ltd.(GSC) ITOCHU Techno-Solutions Corpration(CTC) Japan Petroleum Exploration Co., Ltd.(JAPEX) JGI, Inc.

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