A Database for Surface Ground Motions in KiK-net

A new KiK-net database is developed based on the surface ground motions recorded between October 8, 1997 and November 14, 2021 from Kiban-Kyoshin network (KiK-net) (https://www.doi.org/10.17598/NIED.0004). The database includes various flatfiles which can be categorized into three types.
Type 1 consists of one flatfile with the information about each ground motion recording. This information includes but not limited to source, path and site properties. The results obtained from F-net (https://www.fnet.bosai.go.jp) is among the source properties, path and site parameters and properties are calculated based on previous studies.
Type 2 consists of six flatfiles that include Fourier amplitude spectra (FAS) and 5%-damped pseudo-spectral acceleration (PSA) of horizontal and vertical components. FAS is smoothed using Konno-Ohmachi (1998) method with two different smoothing parameters b=20 and 40.
Type 3 consists of fifteen flatfiles that include (a) average horizontal-to-vertical spectral ratio (HVSR) and its corresponding standard deviation, and (b) the maximum-likelihood estimate of site fundamental frequency (f_ml), its corresponding amplitude (A_ml), and their associated uncertainties based on Yazdi et al. (2022). The HVSR and HVSR-based proxies (i.e., f_ml, A_ml and their uncertainties) are calculated for FAS (b=20), FAS (b=40) and PSA.
This database presents (a) the latest important earthquakes which are not available in the previous databases, (b) the FAS and PSA of both horizontal and vertical components, (c) the average HVSR and the HVSR-based proxies. In addition, the flatfiles in this database can be used by engineers and seismologists to improve/develop ground motion models for Japan.