Changes in the Equilibrium Position of a Sensitive Torsion Balance Placed at Inuyama in Relation to Flood Flows in the Nearby Kisogawa River

Abstract

A sensitive torsion balance was installed at a place of Inuyama town and continuous observations have been made of the change in its equilibrium position. The instrument was placed at a point on the bank of the Kisogawa river, which flows through the town, with the intention to investigate the change in the gravitational potential around the instrument caused by the rise and fall of the level of the river water, especially at the times of flood flows.Calculations have shown that the observed deflections fall much short of those expected from the visible changes in the level of the river water, thus suggesting there are notable changes in the underground water conditions associated with the floods.