Preliminary study of an intermittent spring in the Michihi-dani (valley), Kitakyushu City, Japan (part. 1)

Abstract

Hydrological features of an intermittent spring are preliminarily described. The spring is located in the Michihi-dani (valley) of which name means an ebb and flow. The phenomenon has been known from the early time of Edo Period, about 300 years ago, but the scientific approach for the spring has not been tried.

The spring issues from a limestone which is a member of the Upper Paleozoic, Kagumeyoshi Formation. A short periodicity, 17 to 40 minutes or so, of the draining is often seen with the flux of a few deciliters to 20 liters per second. When the periodicity is relatively long, the spring is nearly or completely dried up in the time of drawdown. When the periodicity is short, however, fluctuations of the draining are merely observed. The hydrograph reveals a feature of gradual increase and decrease.

The periodical flowing out sometimes stops unexpectedly for a while, probably caused by the earth tide, and a large quantity of gush abruptly begins after long interruption and changes in succession to the short periodicity of flowing out after a short time.