Estimated liquefaction areas along (a1) Tokyo Bay and (b1) the Tone River. Observed liquefaction through field surveys conducted by KRDB and JGS (2011) overlaid on the estimated liquefaction for the waterfronts along (a2) Tokyo Bay and (b2) the Tone River. Red and blue indicate liquefaction and non-liquefaction areas, respectively, detected by field survey. Yellow and orange areas indicate the negative coherence areas below the coherence reduction threshold value. Significant coherence reduction cannot be estimated in gray areas where coherence in preseismic pair is less than the threshold value. Bold black lines indicate the Tone River.