阿武山観測坑内における湧水の連続観測

Abstract

Continuous observation of crustal deformation has been operated at Abuyama observation vault since 1972. And a sampling observation of discharge of ground water has been held at a regular interval of one week. For the purpose of investigating the short period fluctuation of discharge, continuous observation by using a rain gauge was started from the end of August 1991.The records have been analyzed for the period from September to December 1991. And a few conspicuous and interesting phenomena are found as follows.1. The discharge of ground water sometimes shows sudden increase up to amounts of 2.5 times of the usual rate and recovers to its original level within a few or several hours.2. A vertical strainmeter records rapid extension almost at the same time with the quick increase in discharge mentioned above.3. No correlation is found in case of usual rainfall with discharge nor with vertical strain. But in case of heavy rainfall, vertical strain shows contraction and recovers to the original level with several days duration. On the other hand, there is no distinguished change in discharge even in this case.