The ESG6 conducted blind predictions to identify the subsurface structure, followed by simulations of ground motions while considering the estimated subsurface structure, for an undisclosed site in the Kumamoto Prefecture, Japan. The ESG6 Blind Prediction is neither a drill nor for training purposes. Moreover, ESG6 neither plans to exercise the state-of-knowledge for estimating subsurface structures nor to predict ground motions in an idealized environment where all necessary information are readily available. Rather, ESG6 intends to improve our understanding about the state-of-art and its effects on an environment where information are sparse or lacking, as occurs in practice.
Step 1. Identification of the subsurface structure at the site
Step 2. Simulation of weak motions observed at the site
Step 3. Simulation of strong motion observed at the site during the mainshock of the 2016 Kumamoto Earthquake
This page is dedicated for opening data that was distributed to the participants of the Blind Prediction exercise for "The 6th IASPEI/IAEE International Symposium: The Effects of Surface Geology on Seismic Motion (ESG6)."
ESG6 was held during August 30th to September 1st, 2021 online, due to the circumstance caused by COVID-19.
Meta and raw data for the exercise, for the three steps, is able to download from this page.
Terms of the use of the distributed data
We do not take any responsibility for any loss or disadvantage caused by using the data. The data shall not be distributed to a third party. When using the data, please clearly state the references and acknowledgments as below.
The array configuration for KUM-SS1 and KUM-S has been plotted on a map, with the information about the station numbers.
Please download the PDF file from here.
Active survey
The length of the active survey line is actually 34.5 m (23*1.5m=34.5m) instead of 36 m as it described in the meta data.
The shooting was done with an offset of about 0.3m from the end of the survey line, and not exactly in the same line as the survey line.
Problem with the data of the N-S component of No.1 instrument
We have discovered that there is a problem with the data of the N-S component of No.1 instrument of the array data.
It seems that there was a problem with the instrument when we made the observation.
We were focused on the U-D component of the array data, so we did not notice about this data.
We have confirmed that the U-D component has no problem.
We do not know the cause of this problem and we are not sure if we can fix this problem.
Please avoid using the N-S component of No.1 instrument of the array data of all array sizes.
Step 2
ZIP file containing raw data can be downloaded from here.
ZIP file contains raw data at the reference site SEVO, "velo_SEVO", report of the geotechnical survey at the target site "KUMA", "Kumamoto Eq. Ground Structure Survey.pdf", the preferred velocity model for the targe site "KUMA", "Preferred model.xlsx", and explanation of Japan Integrated Velocity Structure Model (JIVSM), Version 1, "JIVSM.txt."
We profoundly thank to Institute of Seismology and Volcanology, Faculty of Science, Kyushu University, and JR Kyushu Railway Company for providing us with seismic records of KU.KMP1 and KUMA, respectively. The documents to describe about the JIVSM data was kindly prepared by Prof. Koketsu and Prof. Miyake of ERI, University of Tokyo.
References
Chimoto, K., Yamanaka, H., Tsuno, S., and Matsushima, S., Predicted results of the velocity structure at the target site of the blind prediction exercise from microtremors and surface wave method as Step-1, Report for the experiments for the 6th international symposium on effects of surface geology on seismic motion. Earth, Planets and Space 75, 79 (2023).
https://doi.org/10.1186/s40623-023-01842-3
Tsuno, S., Nagashima, F., Kawase, H., Yamanaka, H., and Matsushima, S., Predicted results of weak and strong ground motions at the target site of the blind prediction exercise as steps-2 and -3, Report for the experiments for the 6th international symposium on effects of surface geology on seismic motion. Earth, Planets and Space 75, 130 (2023). https://doi.org/10.1186/s40623-023-01885-6
Matsushima S., Yamanaka H., Tsuno S., Chimoto K., Suzuki H., Kawase H., Investigation of the subsurface structure at the target site in Kumamoto, Japan and the distributed data of the blind prediction exercise, Report for the experiments for "The 6th International Symposium on Effects of Surface Geology on Seismic Motion" (2023), submitted to Earth, Planets and Space
Koketsu, K., Miyake, H., Afnimar, and Tanaka, Y., A proposal for a standard procedure of modeling 3-D velocity structures and its application to the Tokyo metropolitan area, Japan, Tectonophysics, 472, 290-300 (2009). https://doi.org/10.1016/j.tecto.2008.05.037
Koketsu, K., Miyake, H., and Suzuki, H., Japan Integrated Velocity Structure Model Version 1, Proc. World Conf. Earthq. Eng., Paper No. 1773 (2012).
