湯村断層の放射能探査

Abstract

Yumura fault is located in northwestern part of Hyogo Prefecture, Southwest Japan. Ithas ENE-WSW direction and more than ten km-length from Kasumi-Cho to Onsen-Cho. Andit is said that the Yumura fault was related to generation of the Yumura hot spring.The survey of r-ray intensity was carried out on and near the Yumura fault in order tolocate the fault, and 737 observation points were utilized.The contour map of r-ray intensity in the area concerned was made by YHP 9845b. Highintensity areas of r-ray are located in the central zones and low intensity areas in the northernand southern parts. It was estimated that the Yumura fault is located in a transition zone fromlow to high intensity areas.R-ray intensities were measured on 8 routes at an interval of 20 m. In this analysis, ther-ray intensity at each point was plotted as a function of S-N coordinates of observation points, and this graph shows the existence of several parts of high and low r-ray intensities. It is in-ferred that transition points from high to low intensities agree with the fault line.In the Yumura spa area, the highest part of r-ray intensity accorded well with the partin which hot springs concentrate and therefore the temperature is high.