Permalink : http://hdl.handle.net/2115/77091

JaLCDOI : 10.14943/gbhu.83.49

We started multi-parameter observations on November 25, 2019 using several physical monitoring instruments at the Shikabe geyser in order to obtain new knowledge on the phenomena associated with the geyser eruption and to understand the mechanism of IBE(Interval between eruptions) change. We confirmed regular pattern of signals corresponding to eruption and quiescence in the observed data. Our data also show that IBE of the Shikabe geyser was not always constant but rather showing characteristic change in time. The average of IBE during normal eruption cycle is about 12.5 to 13.5 minutes. IBE sometimes becomes 2-3 minutes longer than the mean interval, and the next IBE is certainly about 1 minutes shorter than the average. Finally, we estimated the hydraulic head of the Shikabe geyser based on the following two conditions obtained from the observed data. 1. Ascent flow rate near the surface of the water level just before overflow; 2. Quiescence time between the end of previous eruption and the start of the next overflow. Hydraulic head value estimated from these two conditions was 1.03-3.73m above the ground surface.