重力変化の長期観測(第1報)

Abstract

Observations with Ichinohe gravity variemeter of double bifilar suspension type havebeen made at 10 stations in Japan since several years ago for the purpose of detailed inves-tigation on time change of gravity. On the ether hand, a long period observation with As-kania gravimeter No. 111 was commenced at the International Reference Station of Gravityof Kyoto in Japan since July 1959 and is being continued up to the present time. Theseobservations will offer the significant information for investigating either micro-change ofgravity or relation between the gravity change and other geophysical phenomena, and willserve for research of earthquake prediction in the near future.In this paper, results obtained by the Askania gravimeter No. 111 during a period ofthe first one year from August 1959 to August 1960 are described somewhat in detail. Aftera detailed discussion, it was concluded that reliability of the value of tidal factor of gravitydetermined by one month's observation was within 3% of its value in the favourable obser-vational condition and suitable correction as in the present case.