Field Detection of Microcracks to Define the Nucleation Stage of Earthquake Occurrence

Figure 4

Geographical relationship between the observation site Hasaki (◆) and the rupture zone 500 km × 200 km (dashed line). Calculated displacement distribution (↗) of the Tohoku Earthquake (★, magnitude 9.0). Also shown are the two largest preshocks, which occurred two days before (⚫, M7.3) and one day before (⚫, M6.8) the earthquake (revised from Suzuki et al. [33]).