High-frequency seismic noise components observed on Cape Erimo, Hokkaido Island, Japan

Initial results derived from the study of high-frequency seismic noise (HFSN) with amplitudes of 10(-9) to 10(-12) m and frequencies of a few tens of hertz were recorded over 2.5 years (from February 1995 to September 1997) in the Cape Erimo area. Hokkaido Island, Japan. The system of observations and data processing methods are described. The inferred results confirm that the HFSN is affected by various external factors such as wind, earth tide, and anthropogenic effects. The case study of components recognized from the HFSN envelope and having periods of the tidal waves O-1, M-2, and N-2 showed that parameters of the response to the tidal effect vary in time. The comparison with the results previously obtained in the Kamchatka region showed that the HFSN response to external effects has features common to both regions.