The mechanism of loro frequency noise and the measures to getting the good records

1995 Fiscal Year Final Research Report Summary

• Project/Area Number: 06452078
• Research Category: Grant-in-Aid for General Scientific Research (B)
• Allocation Type: Single-year Grants
• Research Field: 固体地球物理学
• Research Institution: Nagoya University
• Principal Investigator: YAMADA Isao School of Sciences Nagoya Univ., 理学部, 助教授 (60022670)
• Co-Investigator(Kenkyū-buntansha): SUDA Naoki School of Sciences Nagoya Univ., 理学部, 助手 (10222069)
• Project Period (FY): 1994 – 1995
• Keywords: earth noise / broad-band / Atmospheric Pressure / bore-hole Seismometer / ボアホール型地震計

Research Abstract

T mechanism of low frequency earth noise and the measures to getting the good records
We have guessed the low frequency earth noise associated with the gradientof atmospheric pressure or the force of wind, so that we observed the low frequency earth noise using a broad-band seismometer (STS-1) and observed the change of atmospheric pressure using a high sensitive barometer at lnuyama seismic station. In order to get the gradient of atmospheric pressure, we observed the change of atmospheric pressure at Nagoya city and Seto city. We analized these data and fined that the wave form of low frequency earth noise does not look like the change of atmospheric pressure gradient around the observation station, but look like the change of atmospheric pressure at lnuyama station.
In addition, we fined that the big low frequency noise in the bore-hole type broad-band seismometer, however these wave form dose not look like atmospheric pressure.
We came to the conclusion that the low frequency noise are a kind of the instrumental noise.