M 9.0 mega quake "unpredictable"
The magnitude 9.0 tremor occurred on March 11th at 2:46 PM, and shook the whole of Japan. It left more than 22,000 people missing or killed ― including those whose deaths were indirectly caused by the disaster. Hundreds of thousands more were forced to abandon their homes.
The jolt generated tsunami waves more than ten meters high, which devastated Japan's Pacific coast and slammed into the Fukushima Daiichi nuclear power plant, causing meltdowns in three reactors.
The disaster was triggered by a massive fault rupture that stretched 450 kilometers long and 200 kilometers wide off Japan's Pacific coast. The fault was rupturing for around three minutes.
The earthquake even altered the geographical shape of Japan. Crustal deformation continues to occur even 14 years on. It also affected Japan's geodetic center ― a reference point located in Tokyo that plays an important role in mapping. The quake shifted it 27 centimeters eastward.
Disaster-response system must be improved
The 2011 earthquake exposed both the strengths and shortcomings of the country's disaster preparedness.
Some municipalities found it hard to respond quickly because government offices and the buildings they had designated as shelters or relief centers were destroyed.
Twenty-eight municipal buildings, primarily in the Tohoku region, became unusable.
The central government has asked local governments to ensure there are alternative municipal buildings to use in the event of a disaster, but progress has been slow in some areas.
Nationwide support efforts ― including search and rescue operations, medical aid and infrastructure restoration ― played a crucial role in the 2011 response. But the system for receiving and coordinating assistance was not fully developed, and the central government struggled to assess and address the needs of the affected municipalities.
These lessons have prompted the government to shift from what's called a "pull-type support", where aid is provided only on request, to a "push-type". Following revisions to the disaster-related laws, Japan now proactively delivers life-saving emergency supplies without waiting for formal requests from local governments.
A deadly underestimation
Many of those who died in the 2011 disaster were killed by the tsunami. One of the reasons for the high death toll may have been inaccurate early estimates about the scale of the disaster.
Even current technology cannot quickly assess the magnitude of an earthquake above 8.0. At that time, the Japan Meteorological Agency initially estimated the earthquake to be magnitude 7.9, leading to a lower estimated height of the tsunami.
The agency has since revised its system to prevent underestimations in the event of a massive earthquake. If there is a risk of underestimating a tsunami's scale, the agency will simply describe it as "huge" to ensure people understand it is an emergency situation.
Tackling disaster-related deaths
The 2011 quake highlighted the critical role that evacuation shelters play in saving lives after a disaster. With an overwhelming number of evacuees, some were forced to seek shelter in official locations where supplies were often insufficient.
There were also communications disruptions and health issues. Some evacuation centers experienced influenza outbreaks due to overcrowding and a lack of partitions.
Decision-making at evacuation centers is dominated by men, and the needs of women are not always considered. Issues include a lack of changing rooms, breastfeeding rooms and designated space for women to dry clothing.
To reduce disaster-related deaths, experts recommend improving shelter conditions by ensuring clean toilets, providing hot meals and creating a calm, comfortable environment for rest.
Immediately after the quake, public transportation paralysis left an estimated 5.15 million stranded in the Greater-Tokyo area, unable to return home.
Experts suggest that number would be as high as 8 million if a major earthquake occurred in the Tokyo metropolitan area. That's prompted concerns about a possible crowd crush. Experts say the best way to prevent that is for people to avoid returning home immediately, but that's a measure that society as a whole should prepare for.
"Lifeline is paramount"
People in northeastern Japan who experienced the massive earthquake and tsunami of 2011 have responded to an NHK survey. Many are calling for the government to step up efforts to restore lifeline services in the event of future natural disasters.
NHK conducted the online survey ahead of the 14th anniversary of the March 11th Great East Japan Earthquake and Tsunami.
The survey was opened to people aged 18 or older, living along the coast of Iwate, Miyagi and Fukushima prefectures, as well as areas where evacuation orders were issued following the Fukushima Daiichi nuclear power plant accident. One-thousand people responded.
They were asked what, based on their experiences, they think the government should focus on to prepare for future disasters. Multiple answers were allowed.
44 percent wanted lifelines such as water and electricity restored promptly, and about 29 percent considered tsunami evacuation measures to be important.
24 percent chose living conditions and management of evacuation facilities as priorities. 23 percent placed importance on quake-resistant houses and furniture, and 21 percent said authorities should provide swift and accurate information.
A man in his 70s living in Miyako, Iwate Prefecture, said the 2011 disaster forced him to live without running water for a week and without electricity for a month.
University of Hyogo Professor Kimura Reo said people across the country are voicing concerns about road cave-ins and other problems caused by aging infrastructure.
He said such concerns are also based on lessons learned from disasters, including the 2024 powerful earthquake that struck the Noto Peninsula in central Japan.
The professor indicated that the survey results may reflect people's strong desire for the government to respond better immediately after disasters.
prepared for another mega-quake
A research team in Japan has warned that unreleased stress energy at an undersea trench off northern Japan has become large enough to possibly trigger a magnitude 9-level mega-quake.
Researchers from Tohoku and Hokkaido universities and the Japan Agency for Marine-Earth Science and Technology released the results of their five-year study of the Chishima Trench off Hokkaido.
A previous massive quake is believed to have occurred near the zone in the 17th century. The government's earthquake panel has said the chances of a quake with a magnitude of at least 8.8 occurring there within 30 years are between 7 and 40 percent.
The team installed GPS observation stations on the seabed in 2019 around the point where an ocean plate sinks beneath a continental plate.
Stations on the ocean plate moved about 8 centimeters per year toward the continental side. But a station on the continental plate where the two plates meet also moved about 8 centimeters in the same direction.
Researchers said this indicates that parts of the plates are firmly joined together and strain may be accumulating.
Assuming that the plates have been joined in a similar way since the 17th-century quake, the team says the built-up strain would be equivalent to the energy released by a mega-quake. The team plans to conduct a study at another location off Hokkaido.
Tomita Fumiaki, Assistant Professor of Tohoku University International Research Institute of Disaster Science, says that memories of the 2011 Great East Japan Earthquake and Tsunami have been fading.
He urges people to be aware that another mega-quake could occur and they should be prepared.