豊橋における地殻変動の連続観測(第1報)

抄録

At Mikawa Crustal Movement Observatory, continuous observations of crustal deformation have been made since January, 1973. The instruments used in the observatory are three silicatube extensometers of horizontal component and a set of watertube tiltmeters specially installed in the gallery. Differential transformers are used for all the instruments. Each silicatube extensometer has two or three detectors so that it is possible to discuss the irregularity of strain. The observation of strain in the period January, 1973 to December, 1973, seems to indicate the following features: the def omation is uniform for short period but not uniform for long period. Continuous ground tilts have been observed with both watertube tiltmeters of float-type and traditional micro-screw-type installed on the same tables which are made of granite. From the observation of ground tilts with watertube tiltmeter of float-type, it is found that this instrument has enough stability for continuous observation of ground tilts.