Harmonization of KiK-net and K-NET Ground-Motion Parameters and Metadata: A Flatfile of 950,000 Three-Component Records Spanning 29 Years
DOI:
https://doi.org/10.26443/seismica.v5i1.1616Keywords:
Earthquake ground motion, strong motion, KiK-net, K-net, flatfile, automatic processingAbstract
We present a new flatfile of automatically processed ground motions recorded by both the Kyoshin (K-NET) and Kiban–Kyoshin (KiK-net) networks in Japan. The flatfile comprises over 950,000 three-component ground motions recorded over 29 years (between May 1996 and December 2025), including the 2024 and 2025 Mw > 7 Noto, Hyuga-nada, and Aomori earthquakes. The ground motions were recorded by 1,047 K-NET surface stations and 702 KiK-net surface and borehole stations, with events ranging from JMA magnitude 2.5 to 9 and distances up to 1,200 km. The records are systematically processed, with detailed metadata describing both event parameters and recording characteristics. The flatfile includes key ground-motion parameters such as peak amplitudes (PGA, PGV, PGD), pseudo-spectral and Fourier amplitudes, and quality indicators like signal-to-noise ratios and usable frequency ranges. This flatfile is the first to integrate K-NET and KiK-net data at this scale, offering a harmonized and comprehensive resource for earthquake engineering research. Hosted in an open repository, it supports diverse applications, including ground-motion modeling, machine learning, and systematic analyses of ground-motion characteristics. The flatfile is available at https://doi.org/10.5880/GFZ.LKUT.2026.003.
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