Horizontal seismic wave at ground surface from transfer function based on ambient noise

Abstract

Earthquake detection can be improved by ensuring that seismometer sites experience little artificial noise in the surrounding environment. To minimize noise, seismological stations should be positioned in rocky mountainous areas without nearby valleys, away from significant human activity. However, such surface sites may be scarce when constructing dense monitoring networks, necessitating the use of underground sites to ensure low noise levels. The Korean Meteorological Administration is currently installing new underground seismometers to increase seismic monitoring capacity. However, seismic data on the ground surface are also required for engineering technological developments (to reduce damage to structural components). Therefore, borehole seismic stations without surface seismometers need to estimate ground surface motion from borehole record data. We propose a transfer function that converts motion within boreholes to surface seismic waves using ambient noise, thereby facilitating estimation of ground surface motions using borehole seismometers. As a result, predicting ground surface motion from borehole record data becomes possible.

Stable operation process of earthquake early warning system based on machine learning: trial test and management perspective

“…As a result, borehole-type seismometers are being installed more frequently than on the ground surface, which is different from other countries. Consequently, methods predicting intensity measures based on boreholes are being developed (Jang et al, 2023;Lim and Ahn, 2023). However, due to the lack of data from the changed observation network, it is challenging to improve P-wave detection accuracy.…”

Development of Seismic Intensity Maps Using Low-Cost Micro-Electro-Mechanical Systems Seismic Network

“…7a and 7d). The KMA map uses borehole seismometers, and the site amplification factor applying to the borehole records is often biased producing biased distribution [48]. [48]Fig.…”

“…The KMA map uses borehole seismometers, and the site amplification factor applying to the borehole records is often biased producing biased distribution [48]. [48]Fig. 7d shows the MMI values from high-performance seismometers located at surface (black dots in Fig.…”