Abstract
By the construction of high rise buildings, long span bridges and large scale oil tanks, the fundamental period interested in earthquake engineering is being long. So, the comparatively long period of soil layers as well as structures is a matter of utmost concerns. Here in this paper, the microseisms are observed along the two geological lines near the center of the Nohbi Plain, by use of the long period seismometer with 10 seconds. The wave forms of observed seisms are digitalized by A/D converter and analysed by the Fourier's Transform technique. The vibrational properties in the Plain is the Range of 0.2 to 0.3 Hz in the low frequency, 0.5 to 0.6 Hz in the middle and 1.5 to 3.0 Hz in the high frequency. The numerical results and spectral forms are discussed and compared with the geological profile of the Plain, the sea wave properties of the Ise Bay, the Bouguer's anomaly and the wave propagation properties.
