1923 Great Kantō earthquake 40,000 who went missing and were presumed dead. According to the Japanese construction company Kajima Kobori Research's conclusive report of September 2004, 105,385 deaths were confirmed in the 1923 quake. The damage from this natural disaster was the greatest sustained by prewar Japan. In 1960, the government declared September 1, the anniversary of the quake, as an annual "Disaster Prevention Day". Because the earthquake struck at lunchtime when many people were cooking meals over fire, many people died as a result of the many large fires that broke out. Some fires developed into firestorms that swept across cities. Many people
2011 Tōhoku earthquake and tsunami and south. From the averaged coupling coefficient of 0.5–0.8 in the source area and the seismic moment, it was estimated that the slip deficit of this earthquake was accumulated over a period of 260–880 years, which is consistent with the recurrence interval of such great earthquakes estimated from the tsunami deposit data. The seismic moment of this earthquake accounts for about 93% of the estimated cumulative moment from 1926 to March 2011. Hence, earthquakes with magnitudes about 7 since 1926 in this area only had released part of the accumulated energy. In the area near the trench, the coupling coefficient