Fig. 4.

(a) A schematic of the estimated magnetization for the first survey in May 2011. Colors from red to blue stand for weak to strong magnetization. The average magnetization intensity is 1.5 A/m. A weakly-magnetized area extends to the north and northwest of Shin-moe-dake. (b) Model resolution. Depending on the spatial density and the altitude of the flight paths, the resolution varies from area to area. Lighter areas correspond to a higher resolution. Northwest of Shin-moe-dake the resolution is lower due to sparser flight paths. (c) Data residual. Red and blue color dots stand for positive and negative residuals, respectively. Dots of darker colors correspond to small residuals. In almost all of the survey area, residuals are less than 10 nT.