It has been 23 days and a week since the earthquakes that observed shaking with a maximum seismic intensity of 6 or higher in Miyagi and Fukushima prefectures.



So far, three people have died, more than 200 people have been injured, and it has taken time to restore the Tohoku Shinkansen and thermal power plants, which continues to have an impact on people's lives.

Around 11:30 pm on the 16th of this month, there was a magnitude 7.4 earthquake with an epicenter off the coast of Fukushima prefecture, and tremors with a maximum seismic intensity of 6 or higher were observed in Miyagi and Fukushima prefectures.



According to the summary as of the 22nd of the Cabinet Office, a total of 3 people died in Miyagi prefecture and 1 person in Fukushima prefecture, and a total of 231 people were injured in the Tohoku and metropolitan areas.

The damage situation is

The damage to the houses is 237, including 3 partially destroyed and 234 partially damaged.



According to the Ministry of Health, Labor and Welfare, the number of households with water outages has risen to about 70,000 at one time.



After that, although restoration progressed, as of the 22nd, 992 households in Fukushima Prefecture are still out of water.

Continuing impact on transportation and lifelines

The impact of traffic continues.



The Tohoku-Hokkaido Line has been interrupted between Koriyama Station and Ichinoseki Station due to the derailment of the train, and JR is aiming for a full resumption around the 20th of next month.



In addition, some of the thermal power plants in Miyagi and Fukushima prefectures have been shut down due to the damage of the earthquake, and on the 22nd, the government issued the first "power supply and demand tight warning" within the jurisdiction of TEPCO and Tohoku Electric Power. Was issued, and the alarm in the Tohoku Electric Power jurisdiction was canceled on the night of the 22nd, but the TEPCO jurisdiction continues on the 23rd.



It takes time to restore facilities related to transportation and lifelines, which continues to have an impact on people's lives and the economy.

Risk of large-scale earthquakes for a long time in the future

According to the Japan Meteorological Agency, the number of earthquakes with epicenters off the coast of Fukushima Prefecture is on a downward trend compared to immediately after the earthquake.



However, since the great earthquake that caused the Great East Japan Earthquake occurred 11 years ago, seismic activity has been active in this area, and there is a possibility that a large-scale earthquake will continue to occur for a long period of time.



On top of that, the Japan Meteorological Agency says that tsunamis may accompany depending on the location of the epicenter and the mechanism of the earthquake, and we hope that we will continue to prepare for severe tremors and tsunamis.

Expert "Strain accumulation and earthquakes are likely to occur"

One week ago, on the 16th of this month, experts analyzed the area around the epicenter of the earthquake that observed shaking with a seismic intensity of 6 or higher in Miyagi and Fukushima prefectures. Experts continue to call attention to areas that have accumulated and may not yet be displaced.



Professor Shinji Toda of Tohoku University, who is familiar with the mechanism of the earthquake, analyzed on the 16th of this month how much "strain" that causes the earthquake is still accumulated around the epicenter area off the coast of Fukushima Prefecture where the magnitude 7.4 earthquake occurred.



In the Pacific region of Tohoku, including off the coast of Fukushima Prefecture, "strain" accumulates due to the impact of the huge earthquake that caused the Great East Japan Earthquake 11 years ago, making it easier for earthquakes to occur inside the plate on the sea side that sinks to the land side. Therefore, a magnitude 7 class earthquake actually occurred in April 2011 immediately after the huge earthquake and in February last year.



When the area of ​​the fault that was displaced by this earthquake was overlaid and analyzed, there is a region that may not have been displaced yet between the faults of the one week ago and the earthquake of April 2011. I found out.



Regarding this area, Professor Toda said, "I am afraid that an earthquake inside the plate similar to the one a week ago may occur. If a similar area is frequently hit by strong shaking, the building will be damaged. There is a risk that it will grow and cause damage, so please be prepared to inspect the building in advance. "



Furthermore, Professor Toda says that this earthquake causes strain to accumulate not only inside the plate on the sea side but also at the plate boundary, making it easier for earthquakes to occur.



Professor Toda said, "If an earthquake occurs at a shallow plate boundary, it may be accompanied by a tsunami, so caution is required."

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