著者

浅川 賢一 田幸 敏治 平田 照二

出版者

公益社団法人 応用物理学会

雑誌

応用物理 (ISSN:03698009)

巻号頁・発行日

vol.48, no.6, pp.519-525, 1979-06-10 (Released:2009-02-09)

参考文献数

11

被引用文献数

1

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A 50 meter modified Michelson interferometer has been installed in an underground tunnel in the Nagatsuta campus of Tokyo Institute of Technology. It is enclosed by vacuum pipes and illuminated by a frequency stabilized 633 nm He-Ne laser. The displacement of the interference fringes is converted to voltage with an accuracy of about 1×10-10. From the spectral analysis of the fluctuations of the interference fringes, it is found that the power spectral densityof the microtremor at the quiet time has peakes at 1 cycle/day and its har-monics, also at 0.3, 0.6, and 3 Hz, and that the values at around 10 Hzincrease when cars pass by on the road near the tunnel.