Vol.9 No.2 2016

Research paper : Constructing a system to explore shallow velocity structures using a miniature microtremor array (I. CHO et al.)−97−Synthesiology - English edition Vol.9 No.2 (2016) and Technology until 2014, and also engaged in liquefaction survey and microtremor exploration. Became Senior Chief Researcher, National Research Institute for Earth Science and Disaster Prevention in 2014, and engages in construction of the subsurface structure model focusing on microtremors, development of system tools, and research on strong motion. Visiting Researcher, AIST from FY 2013.AuthorsIkuo CHOCompleted the doctor’s program at the Division of Earth and Planetary Sciences, Graduate School of Science, Kyoto University in 1999. Lecturer, Institute of Seismology and Volcanology, Faculty of Science, Hokkaido University in 1999. Assistant, Faculty of Engineering Division 1, Tokyo University of Science in 2000. Senior Researcher, Geo-Research Institute in 2002. Joined AIST in 2005. Promoted the research for seismogenic process as Senior Researcher at AIST to 2014, and also engaged in research on microtremor exploration. Became in charge of active fault evaluation as Senior Specialist for Earthquake Research at the Headquarters for Earthquake Research Promotion, Ministry of Education, Culture, Sports, Science and Technology in 2014. Engages in research on geoinformation focusing on microtremors as Senior Researcher, AIST in 2015. Visiting Researcher, National Research Institute for Earth Science and Disaster Prevention in 2015.Shigeki SENNACompleted the course at the Department of Geology, Graduate School of Natural Science and Technology, Kanazawa University in 1994. Joined Dia Consultants Co., Ltd. in 1994. Researcher, National Research Institute for Earth Science and Disaster Prevention in 2003. Completed the doctor’s course at the Department of Built Environment, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology in 2008. Engaged in the National Seismic Hazard Map Project as Researcher and Visiting Researcher at the Headquarters for Earthquake Research Promotion, Ministry of Education, Culture, Sports, Science Discussions with Reviewers1 OverallComment (Akira Kageyama, Research Support Adviser, AIST; Chikao Kurimoto, AIST)The microtremor array exploration method allows estimation of the S-wave velocity structure at several tens of meters to several kilometers underground, as well as assesses the shakiness by earthquakes. In this paper, the target is specified to shallow ground, and the goal is set to clarifying the subsurface S-wave velocity structure at high density, high resolution, and quantitatively, for the urban areas in which damage due to strong motion and liquefaction are expected. The authors appropriately present the progress of their research along a steady scenario, including correct response to social demands, theoretical development of miniature microtremor array analysis, application to existing microtremor array technology, development of an automatic analysis system, and actual trial by general users. Therefore, we consider this paper appropriate for publication in Synthesiology. Also, this paper shows that a system can be given an innovative function by advancing the core technology with a new idea, in a system that is composed of multiple elemental technologies. It can be said that it proposes a new synthesis method for papers of Synthesiology.2 OutlineComment (Akira Kageyama, Chikao Kurimoto)Please state, “How the results of this research is useful to society.” Also, you give as the goal of research, “to provide information for subsurface S-wave velocity structure,” but I think the readers can deepen their understanding if you also address the ripple effect of this research.Answer (Ikuo Cho)The subsurface S-wave velocity structure is directly linked to the “shakiness or stiffness of the ground.” If this information can be obtained at high density and high resolution, it will lead to “dramatic improvement of the forecasting precision of earthquake shaking.” I explained this point in the beginning.3 Composition of the paper and its significance in synthesiologyComment (Akira Kageyama)The technology described in this paper is development of new technology including the theoretical investigation specifically for earthquake disaster prevention and mitigation, by enhancing the exploration precision of surface geology, using as a fundamental system the microtremor array exploration that one of the authors has been researching and putting to practical use for many years. It is an attempt for complementarity and strengthening of the fundamental system using new technology, and provides a new type of paper configuration for Synthesiology. Please keep this in mind and review the composition of the whole paper.Answer (Ikuo Cho)As you indicated, we wrote this paper as an example where the problem that could not be solved with conventional 579 (1998).[29]S. Sato, M. Higashi, S. Higuchi, A. Inada, A. Ito, H. Iwamoto, S. Kamikaseda, K. Kawasaki, K. Kusunoki, S. Shinada, K. Suenaga, T. Watanabe, S. Senna and H. Fujiwara: Geological interpretation of a liquefied area by ‘i-bidou’: A case study in the Urayasu area, Japan (2), Abstracts, Japan Geoscience Union Meeting (2014) (in Japanese).[30]H. Iwamoto, M. Higashi, S. Higuchi, A. Inada, A. Ito, S. Kamikaseda, K. Kawasaki, K. Kusunoki, S. Sato, S. Shinada, K. Suenaga and T. Wabanabe: Ground damage on manmade land caused by the 2011 Off the Pacific Coast of Tohoku Earthquake—The characteristics of dredged silt formed reclamation, Abstracts, 119th Annual Meeting of the Geological Society of Japan (2012) (in Japanese).[31]S. Senna, H. Matsuyama, K. Jin, J. Wakai, T. Maeda and H. Fujiwara: Estimation of velocity structure and modeling the subsurface structure of Kanto area based on microtremor array observation, Proceedings of the SEGJ Conference 133 (2015) (in Japanese).[32]T. Nakazawa, S. Nonogaki and Y. Miyachi: Three-dimensional urban geological map—New style of geoinformation in an urban area, Synthesiology, 9 (2), 73–85 (2016) (in Japanese).


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