
Wednesday, October 11, Ibuka Masaru Memorial Hall (1F)

Session	Anv. Sympo.: Resources (Oil, Gas, Metal, and Geothermal)
Conveners	Jun Matsushima (University of Tokyo, GSFS) and Eiichi Arai (JOGMEC)

October 11	10:10～11:40 Efforts for low-carbon and decarbonization toward a sustainable society are accelerating internationally. Clean energy technologies, which are important in this context, require more materials than power generation technologies that use fossil fuels. Achieving the climate change targets specified at the Paris Agreement will require the deployment of more of these clean energy technologies, which will result in even greater use of mineral resources. In the meantime, exploration for mineral resources is becoming increasingly difficult, and coupled with the trend to avoid initial exploration, the discovery rate of new mineral deposits has continued to decline in recent years. It is obvious that a lack of new deposits will lead to a lack of mineral resources in the future, and from a long-term perspective, it is necessary to leverage early exploration. In geophysical exploration technology, it is necessary to solve the challenges of (1) improving the economic efficiency of exploration, (2) obtaining truly necessary exploration information, and (3) obtaining information that cannot be obtained using conventional methods. To this end, it is essential to bring together the experience, knowledge, and wisdom of industry, government, and academia on an international scale.	1) Historical Review and Prospects on Geophysical Exploration Technologies for Mineral Exploration
October 11		*Kazuya Okada(1) Japan Organization for Metals and Energy Security
October 11	10:10～11:40 The Japanese government has supported development of the renewable energy including geothermal for battling against global warming and securing domestic energy resources since around 2012. Many conventional geothermal development activities have been conducted at promising sites with the government supports. New geothermal developing methods of EGS (Enhanced/Engineered Geothermal Systems) and supercritical geothermal resources have also been developed. Geophysical exploration technologies are essential to construct underground structures models and evaluate geothermal reservoirs for reducing geothermal development risk and monitoring environmental impacts. In this presentation recent geothermal development methods and geophysical exploration technologies applied not only to conventional geothermal resources, but also to EGS and supercritical geothermal resources are overviewed.	2) Geophysical Exploration Technologies for Geothermal Development
October 11		*Hideshi Kaieda(1) 1:CRIEPI,Kajima Corp.
October 11	10:10～11:40 The E&P business environment has changed dramatically in recent years, and its goal is set to achieve a carbon neutral society as well as a stable energy supply. In response, JOGMEC formulated a new technology business strategy, as well as the JOGMEC Law was amended. Technical themes related to the CCS business including CCS site survey and CO2 monitoring are expected to take significant contributions from the field of geophysical exploration. In the conventional E&P business, the geophysical exploration is expected to contribute, particularly in the areas of the advancement of technologies related to seismic data acquisition, processing, and analysis. In addition, technologies for mechanization, automation, efficiency, and cost reduction are also expected to be largely developed.	3) Initiatives in the oil and gas industry for realization of a decarbonized society and stable energy supply and contributions from exploration geophysics
October 11		*Ayato Kato(1) 1:Japan Organization for Metals and Energy Security
October 11	10:10～11:40 In oil and gas exploration, the reduction of greenhouse gas emissions in the exploration and development(E&P) is an important perspective to achieve both the social demand for carbon neutrality and stable resource supply. More business development of aquifer CCS and CCUS with enhanced recovery will become inevitable in the next 10 years. In addition, it is also crucial to improve the efficiency of E&P costs through the adoption of digital technology, and to monetize E&P projects at an early stage. Under these circumstances, the development of various technological elements for geophysical exploration including data acquisition, processing, analysis, and evaluation is indispensable for the generation of a sophisticated subsurface digital twin to improve the accuracy of understanding and predicting the time history of subsurface fluid flow over a period of decades or more.	4) Recent Advances in Oil and Natural Gas Exploration Technologies toward Achieving Carbon Neutrality
October 11		*Susumu Abe・Kenichi Akama(1) 1:JGI, Inc.


Session	Anv. Sympo.: Environment (Soil, Groundwater, CCS, and Geological Disposal)
Conveners	Yuji Mitsuhata (AIST) and Takao Nibe (JAPEX)

October 11	13:00～14:30 When construction work is carried out near saltwater wells, it is important to understand the groundwater flow pattern to assess construction impacts on well water. This research studies the result of the exploration of seepage path focusing on low resistivity of intruded saltwater using Simplified Three-Dimensional (3D) Electrical Resistivity Survey. Based on the generated 3D resistivity model, low resistivity zone assumed to be saltwater path is identified continuously from the target well to be preserved to the nearby construction site. Thus, the construction impacts to the well water are assessed as not negligible. The simplified 3D Electrical Resistivity Survey is a fast and inexpensive method to generate a simple 3D resistivity model, useful for simple identification of complex seepage characteristics such as rock fracture seepage.	5) Simplified Three-Dimensional Electrical Resistivity Survey for Groundwater Exploration
October 11		*Shinya Tanioka・Masaru Sasaki・Takeshi Yoshikawa・Yuji Hachino(1) 1:Kiso-Jiban Consultants Co., LTD
October 11	13:00～14:30 In site investigations for the geological disposal, it is necessary to select a geological environment in which the significant effects of natural phenomena are avoided and the favorable characteristics from the viewpoint of geological disposal are maintained stably over a long period of time. This paper describes the concept and procedure for selecting such a stable geological environment, also introduces the current state of geophysical exploration technology as techniques for investigating and evaluating the geological environment from the deep geological disposal requirement.	6) Current status of geophysical exploration techniques for selection of geological disposal site
October 11		*Toshiyuki Matsuoka(1) 1:Nuclear Waste Management Organization of Japan (NUMO)
October 11	13:00～14:30 Japan CCS Co., Ltd is conducting time-lapse seismic surveys in the Tomakomai CCS Demonstration Project commissioned by the Ministry of Economy, Trade and Industry (METI) until FY2017 and by the New Energy and Industrial Technology Development Organization (NEDO) thereafter. The water depth of the survey area is less than 10m to about 40m, and the main target reservoir for the survey is the Moebetsu Formation at a depth of about 1000m. Prior to CO2 injection, the 3D and 2D baseline surveys were conducted. Since the start of the CO2 injection, six monitoring surveys have been completed. During CO2 injection from Apr. 2016 to Nov. 2019, the 1st, 2nd, and 3rd monitor surveys were conducted. In the post-injection phase, the 4th, 5th, and 6th surveys were conducted by FY2022. In the 2nd ,3rd and 4th monitor surveys, time-lapse seismic processing results showed amplitude anomalies detected at cumulative CO2 injection of 65, 207, and 300 kilotons. Although the changes in the post-injection phase were smaller than the changes during injection, there is a possibility that the homogenization of CO2 saturation in the reservoir has been detected.	7) Time-lapse seismic surveys in the Tomakomai CCS Demonstration Project
October 11		*Ryuji Niiro(1),Hideo Saito・Hirokazu Ishige(2),Hisao Kato・Daiji Tanase(1) 1:Japan CCS Co., Ltd.,2:JGI, Inc.


Session	Anv. Sympo.: Geophysical Exploration from Space and Air (Remote Sensing and Drone Survey)
Conveners	Shuichi Rokugawa (NIED, University of Tokyo) and Naoki Sakai (NIED)

October 11	14:50～16:20 The use of satellite remote sensing data has entered a new phase as the rise of small commercial satellite industries. While the variety of available satellite data resources has increased the number of user options, it has become necessary to systemize an optimal data utilization plan for user needs. This paper discusses satellite applications for disaster management from the user's point of view. The importance of usage of satellite orbital elements (TLEs) and the close collaboration with the drone observation are emphasized.	8) New Phase for Utilization of Satellite Remote Sensing
October 11		*Shuichi Rokugawa・Hitoshi Taguchi・Naoki Sakai・Habura Borjigin(1) 1:National Research Institute for Earth Science and Disaster Resilience
October 11	14:50～16:20 To assess the risk of slope vulnerability due to rainfall, it is essential to know the internal structure of the ground and the movement of water. It is necessary to conduct rational risk assessment by integrating airborne and ground-based observation information. In order to efficiently promote rehabilitation and reconstruction, it is important to establish a 3D model created by processing various types of information using AI, and to assess it by physical simulation considering the environmental conditions.	9) Challenges in rational assessment of landslide risk by integrating airborne and ground-based observation information
October 11		*Naoki Sakai(1) 1:National Research Institute for Earth Science and Disaster Resilience
October 11	14:50～16:20 In recent years, disasters have become more severe due to climate change. In flood disasters, efforts are being made to grasp flood damage over a wide area using satellite data and to provide information. In the second phase of SIP, efforts have been made to quickly provide an overview of flood disasters, mainly using emergency observation data from ALOS-2. We report some of the efforts and results.	10) Advanced utilization of satellite data for disaster prevention
October 11		*Naruo Mushiake・Norichika Asada・Kenichi Honda(1) 1:Kokusai Kogyo Co., Ltd.
October 11	14:50～16:20 The Sediment Disaster Prevention Technology Center, together with the Kii Sankei Sabo Office, is studying methods of dealing with large-scale sediment disaster such as deep-seated landslide. In this paper, we report on the application of airborne electromagnetic surveys and SAR images in the Kii Mountains. By using airborne electromagnetic survey technology, it was found that the effect of faults on the behavior of groundwater can be visualized, so it is highly applicable to structural surveys inside slopes. It was confirmed that the utilization of SAR images is useful for investigating the occurrence of large-scale sediment disasters in a wide area and conducting rapid facility inspections.	11) Efforts for the response of large-scale sediment disaster in Kii Mountains using airborne electromagnetic survey and SAR images
October 11		*Wataru Takeshita(1),Masanao Kobayashi・Yuki Kishimoto(2), Takao Yamakoshi(1) 1:NILIM, Sediment Disaster Prevention Technology Center,2:Sediment Disaster Prevention Technology Center,Kii Sankei Sabo Office


Wednesday, October 11, Room No.1 (3F)

Session	SEGJ Conf.: Poster Sessions (Core Time First Half)
Chair	Yuji Mitsuhata (AIST)
[Volcano][Geothermal]
October 11	16:30～17:30 JOGMEC has recently drilled a heat hole in the Shibetsu aera, eastern Hokkaido to estimate geothermal potential of the area. In this study, we have made laboratory measurements of density, magnetic susceptibility and natural remanent magnetization (NRM) of rock samples extracted from drill cores in the heat hole at an interval of 5 m. All the specimens from Miocene andesitic Churui Formation indicate high magnetic susceptibilities and low NRM intensities and Qn ratios. This relationship is similar to that of plutonic rocks like granites. Two-thirds of the specimens show negative NRM inclinations (reverse polarity). Whereas specimens from basaltic dikes represent high magnetic susceptibilities, high NRM intensities and Qn ratios, and negative NRM inclinations. Both normal and reverse type magnetic anomalies are distributed in the study area and magnetic anomalies with a reverse polarity can be attributed to reversely magnetized basaltic dikes. It is noted that old formations like Churui Formation can be subject to the magnetic anomalies with a normal polarity instead of young Quaternary volcanic products in the study area.	P-1) Petrophysical study on core samples from a heat hole
October 11		*Shigeo Okuma・Yoshihiro Ishizuka(1),Keiichi Shibuya(2) 1:AIST,2:previously AIST
October 11	16:30～17:30 In this study, we focused on the magnetic structure related to the hydrothermal system at Oana Crater of Mt. Azuma, which is at risk of eruption in the Tohoku region, NE Japan. In Azuma volcano area, an airborne EM and magnetic survey using manned helicopter was conducted in 2013 (MLIT, 2014). In a limited area close to Oana Crater, a drone magnetic survey has been conducted by the research group headed by Tohoku Univ. in 2021 (Yonekura et al., 2023). In order to determine the progression of volcanic activity at Oana Crater, a temporal change of magnetic anomaly was extracted from aeromagnetic data measured in 2021 and 2013 using the generalized mis-tie control method (Nakatsuka and Okuma, 2006). This method can efficiently extract a temporal change at the intersections of two survey lines while considering changes in elevation. The results will be reported in our presentation.	P-2) Estimation of a temporal change of the magnetic structure in Mt. Azuma, northeast Japan
October 11		*Hikari Yonekura(1),Masahiro Ichiki(2),Shigeo Okuma・Ayumu Miyakawa(3),Ryo Tanaka(4),Toshiki Kaida(2),Ayuta Tsuge(4),Toyonobu Ohta(5),Takeshi Hashimoto(4) 1:Tohoku Univ.,AIST,2:Tohoku Univ.,3:AIST,4:Hokkaido Univ.,5:Tierra Tecnica
October 11	16:30～17:30 We have introduced a 3D inverse scheme for the magnetotelluric (MT) problem using the non-linear conjugate gradient method. Merely two or three forward modeling operations and one adjoint calculation per frequency are typically necessary to effectuate the model update at each iteration. This efficiency is realized through the integration of a straightforward line search process, which advocates for a significant reduction in the objective function, rather than pinpointing its minimum along a specific descent trajectory. Another benefit in the scheme is sought by integrating a regularization divergence-free and multi-resolution approach to accelerate solution convergence. Despite these efficiencies, the authenticity and intricacy of the solution remain constrained by the speed and memory capacity of serial processors. To surmount this hurdle, the inversion scheme also accommodates parallel computing and proves the stability of the inversion algorithm.	P-3) Three-dimensional magnetoelectric inversion based on nonlinear conjugate gradient method using accelerated forward and adjoint calculation technique
October 11		*Jian Li(1),Yasuo Ogawa(2),Jianxin Liu・Rongwen Guo・Xulong Wang・Jingdao Xu(3) 1:Central South University and Tokyo Institute of Technology,2:Tokyo Institute of Technology,3:Central South University
October 11	16:30～17:30 The magnetotelluric (MT) method is an electromagnetic exploration method that uses natural electromagnetic field variations to estimate the resistivity structure of the subsurface based on the ratio of the electric and magnetic fields. The MT method is used not only for geothermal exploration but also for mineral resource exploration and petroleum exploration. Furthermore, the MT method's ability to probe deep subsurface has been utilized in geophysical studies of the crust and mantle. In this study, we focus on the data processing of time series data for the MT method to deepen our understanding of the method and to examine the problems of the previous methods. For this purpose, we developed an improved cascade decimation program and a program to create artificial MT time series data. In the process of developing both programs, we discovered that the conventional apparent resistivity equation was incorrect.	P-4) Common sense and uncommon sense in magnetotelluric method
October 11		*Hideki Mizunaga・Toshiaki Tanaka・Koji Hashimoto(1) 1:Kyushu University
[Case Study]
October 11	16:30～17:30 We conducted ground vibration observations at the Higashiyama Campus of Nagoya University in 2022. The Nagoya Municipal Subway Meijo Line runs irectly underneath the campus, and the vibration originated by the subway trains arriving at and departing from Nagoya University Station is observed. We installed two orthogonal linear seismometer arrays 50 m long, one parallel and one perpendicular to the subway line, above the subway, and conducted three-hour microtremor observations for each line. The observation data clearly showed the vibration from the subway. The characteristics of the waveforms and spectra show differences depending on the running direction and were investigated using a simple train vibration model. Array analysis was applied to estimate information about running subways. Synthesized virtual shot-gathers based on seismic wave interferometry detected wave groups presumed to be surface waves and P-waves propagating along the ground surface.	P-5) Ground vibration measurement at Nagoya University Higashiyama Campus: Analysis of subway running vibration
October 11		*Toshiki Watanabe(1),Keiichiro Sato(2) 1:Nagoya Univ.,2:Japan Coast Guard
October 11	16:30～17:30 This study evaluates the use of magnetic susceptibility and magnetization vector inversion techniques to identify polymetallic mineralization in Afghanistan's Panjshir area. A ground magnetic survey was conducted to collect high-resolution magnetic data, revealing magnetic anomalies linked to polymetallic mineralization. These anomalies are spatially associated with geological formations, indicating potential mineral deposits. The combined interpretation of magnetic susceptibility inversion and magnetization vector inversion data helps understand the geological processes influencing polymetallic mineralization formation. The findings enhance resource assessment efforts, advance mineral exploration techniques, and promote sustainable mining growth in this economically crucial area.	P-6) Magnetic Susceptibility Inversion and Magnetization Vector Inversion: A Case Study for Polymetallic prospecting in Panjshir, Afghanistan
October 11		*Mohammad Hakim Rezayee・Hideki Mizunaga(1) 1:Kyushu University
October 11	16:30～17:30 Cross-well seismic feasibility study for evaluating reservoir characterization and subsurface structure was conducted for a CO2 injection well and a production well for enhanced gas recovery by CO2 injection into a depleted gas reservoir in the Hirai area of the Higashi-Kashiwazaki gas field. Sensitivity analysis of Distributed Acoustic Sensor (DAS) by ray tracing and synthetic waveform study by two-dimensional acoustic Full Waveform Inversion (FWI) were performed to consider data acquisition specifications such as source and receiver locations. Checkerboard tests with different source and receiver locations were conducted as the synthetic waveform study by the FWI. Both the results of the sensitivity analysis of DAS and the synthetic waveform study by the FWI showed that it is essential to set the source and receiver locations as wide as possible.	P-7) Feasibility Study of Cross Well Seismic Survey Using DAS Cable for CO2 Injection in a Depleted Gas Field
October 11		*Akira Fujimoto・Ayato Kato(1),Kono Akihiro(2),Yasushi Shimano・Yusaku Konishi(1) 1:JOGMEC,2:INPEX Corporation


Session	SEGJ Conf.: Poster Sessions (Core Time Second Half)
Chair	Yohei Morifuji (CRIEPI)
[Resource Exploration][Oil and Natural Gas][CO2][Metal]
October 11	17:30～18:30 In Carbon Capture and Storage (CCS) projects, injection of CO2 has the potential to trigger induce seismicity. Continuous monitoring of microseismic (MS) and analyzing its spatial distribution may enable us to interpret the extension of CO2 plumes and a change of surrounding stress state. The major advantages of Distributed Acoustic Sensing (DAS) measurement are dense spatial sampling and cost-effective long-term monitoring. As few studies have delved into the impact of DAS measurement geometry on MS location analysis in multiple wells, in this study, we investigated the accuracy of MS location through DAS under certain conditions with synthetic data. MS source locations from DAS are largely affected by the well geometry and errors in P-wave arrival time. We also found that adding single surface station significantly improves the results. Therefore, combination of surface station with borehole DAS measurement is the effective approach for MS location analysis. Integrating both observation systems will be a further challenge.	P-8) Feasibility study for microseismic source location using DAS observation in multiple wells
October 11		*Akihiro Kono・Isao Kurosawa・Yuki Kobayashi(1) 1:INPEX
October 11	17:30～18:30 In considering the implementation of geological CO2 storage, it is important to develop inexpensive and efficient monitoring technology. Distributed Acoustic Sensing (DAS) which is measurement using optical fiber cables is one of the important sensing technologies, and it is possible to acquire a large amount of data efficiently. In addition to installation into borehole, there are also cases of DAS measurement using existing optical fibers (Dark Fiber) on the ground surface or on the seabed. Dark Fiber can easily start DAS measurement using an existing fiber cable, but there are problems such as limitations on places where measurement can be performed, and data quality is inferior to using DAS-dedicated fiber cables because it is a communication cable. Therefore, we are focusing on Surface-deployed DAS (Surface DAS) measurement that newly deploys fiber cables on the ground for measurement, but it is necessary to confirm the cost of measurement work. In this paper, based on the field trial conducted this year, we examined the cost of Surface DAS measurement work compared with the acquisition of seismic using conventional geophones.	P-9) the Operation Cost Comparison of the Surface DAS using Ground-mounted Optical Fiber and the Measurement using Geophone - Based on the Field Test in Niigata Prefecture
October 11		*Ryohei Naruse・Yuki Kobayashi・Shogo Masaya(1) 1:INPEX
October 11	17:30～18:30 The Afghan Tajik basin, located in the depression zone between the mountain axes, experienced compression, and deformation during the collision of India with the Eurasian plate. While the southern part of this basin remains relatively unexplored, it holds significant potentials for oil and gas resources. The Afghan Tajik basin depositional environments resulted from mixing terrestrial and marine systems, which has potential prospects of Jurassic and Tertiary in shallow petroleum systems. We used 2D regional seismic profiles with a total length of 674.8 km over an area of 2500 km2 in the southern part of the basin. To characterize hydrocarbon systems and structure in this study area, we applied advanced seismic attribute such as spectral decomposition 10 - 60Hz based on time-frequency analysis. The spectral decomposition results yield the averaging 20 - 30Hz group spectral amplitude anomaly. Based on this anomaly result, seismic, and structural interpretation, potential hydrocarbon accumulations were inferred around the main thrust folds in the Tertiary Paleogene and Neogene petroleum systems, which appeared to be accumulated around the central study area. Furthermore, it seems that hydrocarbons dominantly migrated along the main thrusts and then concentrated around anticline fold systems, which could be sealed by mudstone/carbonate rocks.	P-10) Subsurface structures related to hydrocarbon migration and accumulation in the middle east: Insights from seismic attribute analysis
October 11		*SAMIM Khari Mohammad(1),Takeshi Tsuji(2),Chanmaly Chhun(1) 1:Kyushu Univ.,2:Kyushu Univ.,Univ of Tokyo
October 11	17:30～18:30 In this study, we tried to experimentally observe the characteristics of the wave propagation phenomenon by continuously irradiating ultrasonic waves to a sand layer containing gas. As a result, after about 650 hours of continuous ultrasonic irradiation, the amplitude of the observed waveform increased as a whole, and after about 800 hours, it was observed that the magnitude of the amplitude stopped at a high level. It is considered that continuous ultrasonic irradiation minimizes the energy loss of the transmitted wave due to the deformation or movement of the bubbles in the sand layer, resulting in energy amplification. Three-dimensional X-ray CT measurements were performed to confirm the presence of bubbles in the sand layer, and it was observed that numerous gas bubbles of various shapes and sizes remained in the sand layer. Such observations of gas bubbles in sand layers do not exist (or are very rare), suggesting the possibility of gas bubble manipulation by ultrasound if true.	P-11) Energy Amplification of Transmitted Wave Observed by Continuous Ultrasonic Irradiation to Gas-containing Sand Layer: Possibility of Gas bubble Manipulation by Ultrasonic Waves
October 11		*Jun Matsushima(1),Masashi Kodama(2),Katsunori Mizuno(1),Toshiyuki Yokota(2),Makoto Suzuki(3) 1:Univ. of Tokyo, GSFS,2:AIST, GSJ,3:Univ. of Tokyo, SoE
October 11	17:30～18:30 In order to verify the effectiveness of the audio-frequency magnetotelluric (AMT) method for the exploration of the skarn deposits, AMT method was measured in an approximately 4 km×3 km square area around the Kamaishi mine, Iwate prefecture, Northeastern Japan. Using the AMT data from 39 sites, three-dimensional analysis revealed a resistivity structure down to an elevation of about -2 km. The resistivity structure is consistent with the geological structure, with the ore body and tuff having low resistivity, and the surrounding diorite, porphyrite and granodiorite having high resistivity. The result indicates that the AMT method can explain the distribution of ore deposits and geological characteristics of the mine without any inconsistency and is effective for the exploration of deep blind skarn deposits.	P-12) Verification experiment of audio-frequency magnetotelluric method for skarn deposit exploration around the Kamaishi mine, Iwate prefecture
October 11		*Ryosuke Umezawa・Shinichi Takakura・Shogo Komori(1) 1:AIST
October 11	17:30～18:30 In this paper, we apply the PINN (Physics-Informed Neural Networks) method to the analysis of gravity values. PINNs, constructed with partial differential equations as constraints, have recently gained traction in various scientific and technological domains. The effectiveness of PINN stems from its ability to differentiate the output value (gravity value) with respect to the input value (spatial coordinate value) combined with the neural network's universal approximation function. Consequently, computations such as the vertical second derivative of gravity values, upward continuations can be executed swiftly. We anticipate that these advancements will significantly revolutionize gravity analysis in the coming years.	P-13) Analysis of Gravity Data by Physically Informed Neural Network (PINN)
October 11		*Matsuoka Toshifumi(1),Azuma Hiroyuki(2),Koshika Kouta・Nozaki Kyozo(3) 1:Fukada Geological Institute,2:Tokyo Metropolitan University,3:OYO


Wednesday, October 11, Room No.2 (3F)

Session	SEGJ Conf.: Poster Sessions (Core Time First Half)
Chair	Kyosuke Okamoto (AIST)
[Earthquake][Disaster Prevention 1]
October 11	16:30～17:30 To investigate the quality of seismic data for earthquake early warning in the railway, we selected a site with quiet environmental vibrations and performed earthquake observations maintained and managed by the RTRI. Several seismographs were installed at Kasama Observatory and we examined the quality of the recorded data. As a result of investigating the quality of seismic data used for earthquake early warning in the railway, we found that the seismographs are available to record a power spectral density of -110 dB. In the future, we will apply the seismic data recorded during the period to the earthquake early warning method and verify the traceability of earthquake early warnings in the railway.	P-14) Investigation on the quality of seismic data for earthquake early warning in the railway
October 11		*Seiji Tsuno(1),Yasuma Nagai(2),Masahiro Korenaga・Masahiko Samizo・Shinji Sato(1) 1:RTRI,2:MEISEI
October 11	16:30～17:30 Genetic Algorithm (GA) and other methods are used to inverse the S-wave velocity structure from Rayleigh wave dispersion curves. However, it has its own problems, such as the inability to model more detailed than the smallest unit of the discretized S-wave velocity and layer thickness. Therefore, a basic study has been conducted to apply Deep Neural Network (DNN) to inverse analysis in order to provide more detailed underground structure estimation than GA. A large number of pseudo two-layer underground structure models consisting of the surface layer and the engineering bedrock were created, and a learning model for estimating the S-wave velocity structure from theoretical Rayleigh wave dispersion curves. In the inverse analysis using DNN, the number of hidden layers, the number of resampling of the frequency information of the dispersion curves and the number of epochs, which indicates the number of cycles of machine learning, were investigated. As a result, it was clarified that the S-wave velocity structure can be estimated most accurately when the number of hidden layers is 5, the number of resampling points is 20 and the number of epochs is 100.	P-15) Fundamental study on the application of Deep Learning for the inversion of Rayleigh wave dispersion curves to S-wave velocity structures.
October 11		*Masaki Yoshino・Tatsuo Kanno(1),Hiroyuki Miura(2),Michiko Shigefuji(1),Tetsuo Abiru(3) 1:Kyushu univ,2:Hiroshima univ,3:Chugoku Electric Power Company
October 11	16:30～17:30 In the strong motion observation record of the Hirono Thermal Power Station in eastern Fukushima Prefecture, a clear pulse wave is confirmed 1.5 to 1.7 seconds before the arrival of the S wave of the vertical component. This pulse wave has the same waveform as the radial component of the S wave and is observed in all types of earthquakes, such as in the slab, at the plate boundary, and in the overhang. It is considered an SP-converted wave from the deep ground structure. The reproducibility of this pulse wave was examined by simulation using velocity structure models with different seismic bedrock depths. As a result, the model with deep seismic bedrock had better reproducibility of the waveform. The observed converted waves are effective for the verification of subsurface structural models.	P-16) Investigation of subsurface structure model using SP-converted waves observed in the eastern part of Fukushima Prefecture
October 11		*Tomiiichi Uetake(1) 1:TEPCO HD
October 11	16:30～17:30 Compared to solely terrestrial or aquatic area, there are few examples of seismic reflection surveys that comprehensively survey land-lake areas, especially for the purpose of clarifying the subsurface structure of lake areas. This time, using the stand-alone ocean bottom recorder OBX , we conducted a P-wave reflection survey to image the subsurface structure below Lake Aoki and the adjacent areas, on the floor of which, the Kamishiro fault of the Itoigawa?Shizuoka tectonic line (ISTL) active fault system is presumed to be distributed. (Kimura et al., 2023). OBX is a recording device with built-in 3-component velocity seismometer and 1-component hydrophone, assuming data recording in an environment where GPS signals cannot be received, such as underwater. In order to obtain accurate time even in an environment where GPS signals cannot be received, an OVCXO with a constant temperature chamber (drift value after correction is less than 0.5msec after measurement for about 30 days) is used. In this report, we analyze the behavior of OBX during observation, and show the result of integrated processing of the lake area and the land area.	P-17) Seismic reflection survey of land-lake area and behavior analysis of OBX during observation
October 11		*Yasuhiko Akinaga・Koji Yamada・Takashi Imayoshi・Masaki Suehiro(1),Haruo Kimura(2) 1:Hanshin Consultants Co., Ltd,2:Central Research Institute of Electric Power Industry
October 11	16:30～17:30 We conducted a shallow seismic reflection survey at KitaAma-TsuTsui area in Minamiawaji City, Hyogo Prefecture, central Japan, to clarify the spatial distribution and the deformation structure of the Minato-Honjo Fault and the distribution structure of the Izumi Group. Preliminary seismic depth-migration sections show reflectors at depths shallower than an elevation of about -150m. Compared with the results of coring surveys and reflection surveys conducted near this survey line, distinct reflectors in this survey show boundaries in the Osaka layer which was deposited in the Pliocene and the Pleistocene period. The distinct positive phases within the Osaka Group show the complex geometry, representing the deformation structure caused by the Minato-Honjo Fault. Preliminary results did not show any evidence of the Izumi Group being uplifted from the west to the area of the Izumi Group, but further study is needed. We will conduct further analyses to gain more insight into the geological information around this area.	P-18) Shallow seismic reflection survey on Minamiawaji city in Hyogo prefecture
October 11		*Sawako Kinoshita・Shinobu Ito(1) 1:AIST


Session	SEGJ Conf.: Poster Sessions (Core Time Second Half)
Chair	Toshiyuki Kurahashi (CERI)
[Civil Engineering][Disaster Prevention 2]
October 11	17:30～18:30 We have been developing a VLF band AC electrical survey system. However, since the data measured by this system are affected by the skin effect, applying the conventional DC inversion method gives different results from the actual subsurface resistivity structure. Therefore, we have been developing a technique to remove the skin effect and generate data suitable for DC inversion. In this study, we attempted to apply deep learning to remove skin effects. Deep learning has the advantage of analyzing data quickly while maintaining computational efficiency even when there are many unknown parameters. Furthermore, it does not require initial model estimation, which is advantageous for removing skin effects. Although the removal results were generally of high quality, there were cases where the removal could not be done correctly, and further improvement and study are needed in the future, particularly with deep learning.	P-19) Removal of Skin Effect from VLC-AC band Electrical Survey System Measurement Data Using Deep Learning.
October 11		*Junya Shinohara(1),Motoharu Jinguuji・Toshiyuki Yokota(2),Takumi Ueda(3) 1:(1)AIST, (2)School of Creative Science and Engineering, Waseda Univ.,2:AIST,3:School of Creative Science and Engineering, Waseda Univ.
October 11	17:30～18:30 Compared with conventional microtremor array measurements, active surface wave surveying has an irreplaceable advantage in utilization of such shot coherent signals as refracted P-waves, reflected P- and SV-waves along with surface waves for the modeling of near-surface velocity structure. Previously we reported the results of repetitive high-resolution surface wave surveys conducted in Hinode District, Itako City over a year. We adopted the “walk-along” surface wave survey method and employed CMP-SPAC analysis to calculate high-resolution dispersion curves. Slight changes in the dispersion curves were distinguished and we correlated them to the changes in water table and rainfall events. In this paper we exemplify that shot coherent signals included in active surface wave survey data are essential for the reconstruction of near-surface velocity structure. Refraction tomography analysis delineated the change in P-wave velocity structure of the superficial zone associated with the pumping of groundwater as the countermeasure for liquefaction. P- and SV-wave reflection processing provided near-surface 2-D time and depth sections along the survey lines. Reflection events were successfully imaged at shallow depths around 2 to 20 m.	P-20) Repetitive multichannel surface wave surveys at Hinode District, Itako City (Part 2): Utilization of shot coherent signals for delineating near-surface velocity structure
October 11		*Inazaki Tomio(1),Yokota Toshiyuki(2) 1:Independent,2:AIST
October 11	17:30～18:30 We developed an automated data acquisition and processing seismic system to continuously monitor S-wave velocity change of ground using array microtremor data. The system consists of several cableless seismograph units including a three-component geophone, a seismograph including GPS, battery, A/D converter, solar panels, and a mobile router to connect to internet. It uploads array microtremor data to a cloud server in real-time without any cables. The server automatically processes the array microtremor data by spatial autocorrelation and detect phase velocity change in real-time. We installed the system consisting of three units to a full-scale test embankment in Tsukuba, Ibaraki, and have been monitoring the phase velocity change more than one year. It clearly detected the phase velocity change associated with the heavy rain in September 2022. The change was reasonably consistent with the tilt change observed by clinometers.	P-21) Continuous S-wave velocity measurements of embankment using seismic ambient noise
October 11		*Koichi Hayashi(1),Osamu Ishitsuka・Takanori Ishikawa・Chisato Konishi(2),Naoki Sakai(3) 1:OYO Corportaion/Geometrics,2:OYO Corportaion,3:NIED
October 11	17:30～18:30 Surface wave Analysis is a method of determining subsurface structure using the dispersion curve of surface waves. There are several exploration methods, but they differ in the way dispersion curve are extracted (surface wave source, seismograph placement, and equipment). The SPAC method and microtremor survey (including Chain Array Method) use seismometers placed on the ground surface to record microtremors, extract the dispersion of surface waves,and estimate the subsurface structure.Microtremors are minute vibrations on the ground surface, and faithfully recording them is the most important part of the exploration.	P-22) Maximum depth and resolution of the surface wave method
October 11		*HISAO Hayashi(1),TOSHIO Takagi・HIDEYASU Uekuma(2),TSUYOSHI Haraguch(3) 1:Geo-x Consultant Corporation,2:F U K K E N C O., L T D.,3:STORY, Ltd.
October 11	17:30～18:30 We investigated seismic wave propagation in crustal structure of the East Anatolian Fault Zone (EAFZ) during the 2020 Elazig earthquake (Mw6.7) using AFAD strong ground motion records. Relatively large PGV was observed along the south part of the EAFZ. The attenuation of PGV was small at the stations located southwest to the epicenter of the event. The pasteups of waveforms toward the southwestern stations showed significant Lg wave with 3.4 km/s. The propagation of significant phase of surface wave with the period of 10 s was also clearly observed in the pasteups in all the components of the velocity waveforms with about 2.7 km/s. Pg phase with 5.8 km/s was also appears efficiently compared with Pn. These Pg, Lg, Love and Rayleigh phases were significantly observed especially at around the rupture area of the 2023 Kahramanmaras earthquake (Mw7.8). Whereas, they were not significantly observed toward the northwestern and other areas. The velocity response spectrum also showed the significant different between the equidistance stations at southwest and northwest to the epicenter.	P-23) Seismic wave propagation in crustal structure of the East Anatolian Fault Zone
October 11		*Kosuke Chimoto(1) 1:Kagawa Univ.


Thursday, October 12, Ibuka Masaru Memorial Hall (1F)

SEGJ 75th Anniversary Event
Event Theme: “Sustainable Society and Geophysical Exploration”


October 12	9:30～10:40	Panel Discussion

October 12	11:00～12:30	Outreach


Session	Keynote Speeches

October 12	14:00～14:45	Susumu Abe (President of JGI, Inc.)
October 12	14:45～15:30	Yasuhiko Kotera (President of JAPT)


October 12	16:00～17:10	Anniversary Ceremony


Friday, October 13, Ibuka Masaru Memorial Hall (1F)

Session	Anv. Sympo.: Disaster Prevention (Slope, Earthquake, and Levee)
Conveners	Hiroaki Yamanaka (Tokyo Tech) and Hiroaki Sato (CRIEPI)

October 13	9:30～11:00 Geophysical exploration has been conducted as a survey related to slope disaster management. Geophysical exploration surveys can efficiently investigate the spatial distribution of geological structures and ground properties. In recent years, due to the development of equipment and measurement/analysis technology, it has become possible to conduct surveys with higher speed and resolution. This paper describes the purpose and method of geophysical exploration surveys for underground structures of slopes, and the points to be noted in interpreting them. In addition, we introduce a case study of the underground structure of a slope by drone electromagnetic survey. It was shown that the geological structure of the slope including the collapsed deposits could be captured by the drone electromagnetic survey.	12) Slope disaster management and geophysical exploration
October 13		*Kenji Kubota(1) 1:CRIEPI
October 13	9:30～11:00 I describe geophysical surveys used to construct subsurface structural model for strong motion prediction. An overview of the status of geophysical surveys in metropolitan areas is presented. In addition to S-wave velocity structural model for the land area, it is important to seamlessly estimate the S-wave velocity structure model for the sea area.	13) Geophysical Explorations for Strong Motion Prediction
October 13		*Haruhiko Suzuki(1) 1:OYO Corp.
October 13	9:30～11:00 In levees which require countermeasure constructions for seepage problems, the use of geotechnical investigation techniques can improve the performance of levees. In practice, however, the amount of using geotechnical investigation techniques for levee investigation is low, and the reason for this may be that the investigation is not required. Therefore, if the existence of uncertainties affecting safety is recognized and it is shown that these uncertainties can be resolved by utilizing geophysical surveys to deal with them, effective utilization of geophysical surveys will be promoted. Therefore, geophysical exploration engineers and those who intend to utilize it need to make efforts to change the situation. In addition, there are many persons to have the impression of unreliability for geophysical surveys, but the reality is that many surveys are not compatible with the purpose of the survey. The efforts to understand the survey objectives even at the time of conducting the survey will contribute to improve the utilization of the survey. I believe it is important to share knowledge and jointly promote technological improvement.	14) Use of geophysical exploration for river levee survey
October 13		*Kyosuke Onishi(1) 1:Public Works Research Institute


Session	Anv. Sympo.: Civil Engineering (Maintenance and Management, and Agriculture)
Conveners	Kyosuke Onishi (PWRI) and Keisuke Inoue (NARO)

October 13	12:30～14:00 Japan belongs to the Pacific Ring of Fire, and the geology is weak and fractured. Therefore, infrastructures are exposed to various geo-risks. Geo-risks develop not only in construction stage but also in maintenance, update and redevelopment stages. Business loss of MLIT by geo-risk occupies about 5% of the general account expenditure. Now, we have to develop geo-risk management systems for more efficient construction and land use. In this presentation, we survey current status of geo-risks in civil engineering by some statistics. And then, we discuss issues on geo-risk management and hope for geophysical exploration.	15) Geo-risks on Civil Engineering and Hope for Geophysical Exploration
October 13		*Yasuhito Sasaki(1) 1:Japan Dam Engineering Center
October 13	12:30～14:00 With the aim of extending the life of agricultural irrigation facilities and reducing life cycle costs, "Stock Management" is being implemented nationwide. In stock management, the cycle of Routine management, Functional diagnosis, Formulation of functional preservation plan, Countermeasure works, and Data accumulation is implemented on a phased and continuous basis. In 2023, the "Handbook for Maintaining the Functions of Agricultural Irrigation Facilities" was revised, adding perspectives on the introduction of new technologies and renewable energy, and expanding descriptions on risk management, so this report provides an overview of those changes.	16) Present Situation of Stock Management for Irrigation and Drainage Facilities
October 13		*Okamoto Yoshihisa・Morioka Saburo(1) 1:MAFF/Tone River Basin and Management Office


Session	Anv. Sympo.: Academic (Earth Science and Buried Cultural Properties)
Conveners	Toshiki Watanabe (Nagoya University) and Akihiro Kaneda (Nara National Research Institute for Cultural Properties)

October 13	14:20～15:50 Planetary exploration is shifting from previous remote sensing missions to direct investigations, including the deployment of landers. Lunar exploration has entered a phase of international collaboration after years of careful consideration. Seismic network observation is recognized as a crucial theme for direct exploration, and research and development in this field have been conducted since the establishment of the Planetary Exploration Division by JAXA in the 1980s. In terms of physical exploration, active seismic investigation has also begun with the consideration of using active seismic sources such as manned rovers to study underground structures. Japan is expected to take a leading role in the field of underground structure exploration.	17) Near-future lunar and planetary exploration plans and expected results from seismic observations
October 13		*Satoshi Tanaka(1),Takeshi Tsuji(2),Akito Araya(3),Taichi Kawamura(4),Keisuke Onodera(3) 1:JAXA,2:Graduate School of Technology Univ. Tokyo,3:Earthquake Research Institute, Univ. Tokyo,4:Université Paris Cité , institut de physique du Globe de Paris, CNRS
October 13	14:20～15:50 In plate subduction zones, such as the Nankai Trough and the Japan Trench, various interplate slip behaviors, ranging from devastating megathrust earthquakes to slow slips which do not cause strong ground motion, have repeatedly occurred. However, the distribution of these interplate slip behaviors show marked spatial variations even along each subduction zone, suggesting spatial variations in the interplate seismic coupling. To assess earthquake and tsunami hazards, it is crucial to identify the factors that control the interplate seismic coupling. The nature of the plate interface, such as the geometry, materials and physical properties like porosity and frictional coefficients, is a key control on interplate seismic coupling. To reveal the nature of the plate interface, we have conducted extensive-scale seismic refraction and reflection surveys from the oceanic plate, an input to the subduction zone, to deep within the subduction zones. In this paper, we show the detailed seismic structure in the Nankai Trough and the large-scale seismic structure of the incoming oceanic plate in the Japan Trench and discuss their potential relationship to the spatial variations in the interplate seismic coupling in both subduction zones.	18) Frontiers of Seismic Exploration in Seismogenic Subduction Zones
October 13		*Gou Fujie(1) 1:Japan Agency for Marine-Earth Science and Technology (JAMSTEC)
October 13	14:20～15:50 The center of Kyoto city, the capital of Japan untill the 19th century, have the several castle sites built in the 16th century. The ruins of these castles were destroyed because of early-modern and modern urban activity, but the ruins of huge moats still exist in underground. We carried out the investigation to detect the location of the burried moats of these castles including famous but also a little-known Jurakudai Castle built in 1586 and destroyed in 1594, using the surface wave method. We got useful data for archaeological research on Jurakudai and other casles, so that we could draw a new reconstruction of these castles applying the surface wave method data and historical data.	19) Application of the surfice wave method to detect the buried moat of the casle sites built in the 16th century
October 13		*Takumi Furukawa(1),Toshitaka Kamai(2),Shun Sakamoto(3),Issei Doi(4),Ryo Nakatsuka(5) 1:Kyoto Prefectural Board of Education,2:Former Disaster Prevention Research Institute, Kyoto Univ.,3:Gangoji Institute for Research of Cultural Property,4:Disaster Prevention Research Institute, Kyoto Univ.,5:Muko City Center for Archaeological Operations
October 13	14:20～15:50 Archaeological Survey using geophysical exploration is a method of non destructive visualization of buried cultural properties. This archaeological survey can be investigated in a shorter period and low costly than excavation. Therefore , it has been used mainly as a preliminary survey for excavation. In t his paper , we report a case study of archaeological survey for efficient excavation and get detailed information without digging. Moreover, w e introduce how geophysical exploration technology contributes to the sustainability of historical heritage.	20) The future of archaeological Survey
October 13		*Naoto Takase(1),Yoshinao Murakami(2),Masahiro Yamaguchi(3),Shinichi Okumura(4),Megumi Kobayashi・Nobuaki Ishizawa・Ken Ichihara(1) 1:OYO Corporation,2:Akita Archaeological Center,3:OUGISEIKO CONSULTANTS Co.,Ltd.,4:TOSHIKEIKAN SEKKEI INC.

VENUE
	INTERNATIONAL CONFERENCE CENTER, WASEDA UNIV., TOKYO, JAPAN and ONLINE

SCHEDULE
	Wednesday, October 11, 2023
		Openning Speech	Ibuka Masaru Memorial Hall, (1F)	10:00-10:10
		__Speaker:	Toshiki WATANABE (Nagoya Univ.; Chair, Executive Committee for Anniversary Events )
		Anniversary Symposiums	Ibuka Masaru Memorial Hall, (1F)	10:10-16:20
		Poster Core Time	Room No.1 & 2 (3F)	16:50-18:30
		Exhibition	Room No.1(3F) & Foyer(1F)	11:00-18:30

	Thursday, October 12, 2023
		Panel Discussion	Ibuka Masaru Memorial Hall, (1F)	09:30-10:40
		Outreach	Ibuka Masaru Memorial Hall, (1F)	11:00-12:30
		Keynote Speechs	Ibuka Masaru Memorial Hall, (1F)	14:00-15:30
		__Chair:	Jun MATSUSHIMA (The University of Tokyo; Vice-President of SEGJ)
		__Presentation(1):	Understanding the Geological Environment and Contributing to Disaster Prevention and Mitigation through Geophysical Exploration Technology - 100 years since the Great Kanto Earthquake Susume ABE (President of JGI)
		__Presentation(2):	The Near Future of Geophysical Exploration Technology Developed with the Evolution of Digital Technology Yasuhiko KOTERA (President of SEGJ)
		Anniversary Ceremony	Ibuka Masaru Memorial Hall (1F)	16:00-17:10
		Banquet	RIHGA Royal Hotel Tokyo (3F) [Access Map to RIHGA Royal Hotel]	18:00-20:00
		Exhibition	Room No.1(3F) & Foyer(1F)	09:30-17:00
	Friday, October 12, 2023
		Anniversary Symposiums	Ibuka Masaru Memorial Hall (1F)	09:30-15:50
		Closing Speech	Ibuka Masaru Memorial Hall, (1F)	15:50-16:00
		__Speaker:	Yoshiya ODA ( Tokyo Metropolitan Univ.; Vice-Chair, Executive Committee for Anniversary Events )
		Exhibition	Room No.1(3F) & Foyer(1F)	09:30-15:00

Registered and Paid		Pre-Registration (Until Sep. 14, 2023)	Onsite Registration
Conference Meeting	Member / Non-member	JPY 15,400-*	JPY 17,600-**
	Student (Member)	JPY 00,000-*	JPY 00,000-**
	Student (Non-Member)	JPY 07,700-*	JPY 08,800-**
Reception (Evening on Oct. 12)	Member / Non-member	JPY 11,000-**	JPY 13,200-**
Reception (Evening on Oct. 12)	Student	JPY 05,500-**	JPY 06,600-**

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

LIST OF EXHIBITORS
	Cosumosu Shoji Co.,Ltd. Geofive Co.,Ltd. Hakusan Corporation Maruma Technica Co.,Ltd. RS Dynamics Co.,Ltd. Tokyo Sokushin Co.,Ltd.

LIST OF ADVERTISEMENTS
	EAGE-NSG Asia Pacific Meeting Geophysical Surveying Co., Ltd.(GSC) ITOCHU Techno-Solutions Corpration(CTC) JGI, Inc. Kawasaki Geological Engineering Co. Ltd.(KGE)