�@ Œf�ÚŽGŽ��i˜a�j�F “ú–{’n�k�HŠwƒVƒ“ƒ|ƒWƒEƒ€˜_•¶�W Vol�F 9-1Šª ”N�F 1994”N •Å�F 175-180•Å ’˜ŽÒ�i˜a�j�F ŒÃ‘º�@”ü’ÃŽq�C�@�ù’J�@“w�C�@�¬–ö�@•q˜Y�C�@âV“¡�@�½Ž¡ ƒ^ƒCƒgƒ‹�i˜a�j�F �\�Ÿ•½–ì‚Ì’·ŽüŠú’n�k“®‰ž“š �´˜^�i˜a�j�F
- ƒL�[ƒ��[ƒh�i˜a�j�F - Œf�ÚŽGŽ��i‰p�j�F PROCEEDINGS OF THE JAPAN EARTHQUAKE ENGINEERING SYMPOSIUM ’˜ŽÒ�i‰p�j�F Mitsuko FURUMURA, Tsutomu SASATANI, Toshiro KOYANAGI, Seiji SAITO ƒ^ƒCƒgƒ‹�i‰p�j�F THE LONG-PERIOD SEISMIC RESPONSE OF THE TOKACHI PLAIN �´˜^�i‰p�j�F
Seismic observations were carried out in and around the Tokachi plain. The comparison of the seismograms obtained by a rock and sediment station pair revealed strong amplification of S waves and strong excitation of surface waves in the frequency range of 0.2 - 1.0Hz in the Tokachi plain. By the semblance and polarization analysis of small-aperture array data on the sedimentary site, it has been found that the surface waves excited in the Tokachi plain were mainly composed of fundamental Rayleigh and Love waves. ƒL�[ƒ��[ƒh�i‰p�j�F - ‹LŽ–‹æ•ª�F - ‹æ•ª �@�@�@ˆÏˆõ‰ï˜_•¶�W