Fig. 3From: Precursory ground deformation of the 2018 phreatic eruption on Iwo-Yama volcano, revealed by four-dimensional joint analysis of airborne and spaceborne InSARDistributions of temporal mean values of coherence (stack coherence) in path a 131 and b 23. The area with stack coherence values of less than 0.4 is masked by black color. The red stars indicate reference pixels in each path. The reference pixels have stack coherence values of 0.56 in path 131 and 0.51 in path 23Back to article page