The Japan Meteorological Agency will no longer use the term "aftershock" for earthquakes that occur in the area around the epicenter of the huge earthquake off the coast of Tohoku that caused the Great East Japan Earthquake.
"Aftershocks" is an expression that may give the impression that a large earthquake will not occur, and is said to prevent a decline in disaster prevention awareness.
The Japan Meteorological Agency has defined the area of 600 km north-south and 350 km east-west where seismic activity became active due to the impact of the huge earthquake off the coast of Tohoku 10 years ago as an aftershock area. And called for attention.
However, the number of earthquakes in the aftershock area is decreasing year by year, and the monthly average value for the year up to last month is approaching the monthly average value for the 10 years before the earthquake. is.
On the other hand, the government's Earthquake Research Committee has stated that along the "Japan Trench" from the Tohoku region to the offshore of the Kanto region, there will be a maximum of 90% or more of large earthquakes with a magnitude of 7 to 7.5 in which the boundary between the plates shifts within the next 30 years. It is evaluated that it will occur with the probability of.
In response to these circumstances, the Japan Meteorological Agency has decided not to describe earthquakes that occurred in this area as "aftershocks," saying that "aftershocks" may give the impression that no major earthquakes will occur.
In the future, the Japan Meteorological Agency wants to prevent a decline in disaster prevention awareness by not expressing "aftershocks" at press conferences when a large-scale earthquake occurs off the coast of Tohoku.