跡津川断層における光波測量 (第1報)

Abstract

In order to detect the slip motion of the Atotsugawa fault, one of major active faults withright-lateral displacements in central Japan, six base-lines for electro-optical distance measure-ment were installed across the fault in and around Nishiurushiyama, Kamiokacho in 1971.The result from the re-surveyings in October 1972 and in November 1976 shows that for thefive years there have occurred no significant changes in all the six base-line lengths beyondthe observational error. This indicates that the fault in this part holds stuck or the sliprate, even if it slips, is less than 2mm/year. This is consistent with the extremely low seis-micity in that portion along the fault.