Fig. 4
From: Tilt and strain change during the explosion at Minami-dake, Sakurajima, on November 13, 2017
a Location of the obtained spherical source (MS, the solid circle) for phase 1 (22:07–22:10) and a comparison of the observed (black) and calculated (white) downward tilts. The error ellipses are 3σ. The 99% confidence level estimated by an F-test (Árnadóttir and Segall 1994) is within the size of the solid circle. The depth of the source MS is 0.1 km bsl. b Comparison of the observed (black) and calculated (white) radial (R), tangential (T) and oblique (O) extensions. The error bars are 3σ