Hundreds of Thousands Face Week-Long Evacuation in Anticipation of Nankai Trough Disaster

Following the issuance of a Megathrust Earthquake Alert, residents in areas susceptible to tsunami flooding are advised to evacuate for a week. This directive is in response to the potential for a devastating Nankai Trough megaquake.

The Cabinet Office announced that a minimum of 520,000 people across the nation will be subject to this week-long evacuation order. This figure was determined through the government's initial survey, conducted under the Nankai Trough Earthquake Extra Information bulletin. This bulletin will issue one of three alert levels when the likelihood of a Nankai Trough megaquake becomes imminent, with the Megathrust Earthquake Alert representing the highest level.

The Cabinet Office guidelines stipulate that when a Megathrust Earthquake Alert is issued, individuals who may not have sufficient time to escape a tsunami are urged to evacuate to areas outside of the expected flood zones for a week. The survey, which took place from June to August, encompassed 707 municipalities across Tokyo and 28 other prefectures designated for enhanced disaster mitigation efforts related to a Nankai Trough megaquake.

Among these municipalities, 130 have already identified areas for advance evacuation. These municipalities are located in Tokyo and 15 other prefectures. Some of these municipalities have already calculated the number of residents who would require advance evacuation.

The total number of people needing to evacuate from these municipalities is at least 520,000, with a significant portion, over half, comprising elderly individuals and people with disabilities who require assistance during evacuation. This number surpasses the 470,000 people who evacuated during the 2011 Great East Japan Earthquake and subsequent Fukushima No. 1 nuclear power plant accident.

While the Cabinet Office has been encouraging municipalities to designate areas for advance evacuation, it has not yet compiled a comprehensive count of all individuals who will need to evacuate. Earlier this year, a separate survey indicated that over 670,000 people reside in areas requiring advance evacuation when a Megathrust Earthquake Alert is issued. In response to this, the disaster management minister stated that the government would thoroughly gather information from municipalities.