FUKUSHIMA – A child in Fukushima Prefecture has been diagnosed with thyroid cancer in the latest health survey to assess the impact of the triple core meltdown that tainted the region with radiation in 2011.
Seven others in the survey of 385,000 children in Fukushima Prefecture are also suspected of having thyroid cancer but have not received a definitive diagnosis, a prefectural committee said. The survey began in April 2014, three years after the Great East Japan Earthquake and tsunami crippled the Fukushima No. 1 power plant.
The child diagnosed and the seven others tested negative in the first survey, which covered all 370,000 children in the prefecture who were 18 or younger at the time of the disaster. Those born a year after the meltdowns were not included.
“Despite the new results, I don’t think we need to change our previous view” that they were not affected by the radiation, said Hokuto Hoshi, who heads the panel.
In the first survey, 86 children were confirmed as having thyroid cancer and 23 were suspected of having it.
In both surveys, the thyroid glands were first scanned with ultrasound to measure the size and shape of any lumps, and assigned four grades of severity. Those children assigned the two highest grades were then given blood tests and cell biopsies.
The child confirmed to have thyroid cancer and the seven suspected of having it were between 6 and 17 at the time of the accident, according to Fukushima Medical University, which conducted the survey.
Arnie Gundersen, nuclear expert and chief engineer at Fairewinds, Jan 29, 2015 (emphasis added): Recent scientific studies from Japan show that 75% of the radiation created by the meltdowns was released more than 5 days after the catastrophe… This data… shows that the total gaseous and liquid radioactive releases from the Fukushima Daiichi meltdown exceedthe radiation released during and after the Chernobyl meltdown — while Fukushima Daiichi radioactivity continues to bleed into the Pacific Ocean… I first spoke to the NRC’s Advisory Committee on Reactor Safeguards in 2010 to share my evidence-based calculations showing that containments would likely leak significant amounts of radioactivity during a nuclear power failure… [They] informed me that, the nuclear industry and NRC simply assume that containments will never leak during nuclear emergencies… Unfortunately, those 3 explosions at Fukushima Daiichi prove that containment systems really do fail… How do we know?… First, you can see the violent explosions and the detonation shock wave on TV and video. The secondpicture though shows there are 2 distinct plumes exiting Unit 3 — one plume emanates from the spent fuel pool, but the other is directly over the reactor vessel… Third, TEPCO itself has admitted that hot gases raging at 250*F were released from the containment… No, it is not steam, because steam only exists at 212*F under normal atmospheric pressure.
Idaho National Laboratory Site’s Environmental Surveillance, Education and Research Program — Annual Site Environmental Report for 2011 (pdf): … [3 of Fukushima Daiichi’s] reactor cores overheated and melted, releasing hydrogen gas and fission products into their reactor containment structures… multiple hydrogen deflagrations occurred that damaged the containment structures and allowed more radioactive material to be released. It is possible that the large hydrogen explosion in Unit 3 may have damaged stored spent fuel and caused the release of additional radioactive material. The Fukushima reactor accident in Japan resulted in the release and global dispersal of radioactive contaminants. These contaminants were transported in air across the Pacific Ocean to the United States…
Radio VR, Aug 23, 2014: Thomas Drolet, who is Chairman, CEO and President at GreenWell Renewable Power Corporation [said] “As a technician and nuclear reactor engineer I can say that they will eventually succeed [at Fukushima Daiichi]“… The reactor itself is by far “the most difficult issue,” Mr, Drolet states. Each of the three damaged reactors has two main areas ofbroken fuel: in the spent fuel base, which is up high, and the reactor core. “Slowly and identically they have to remove that fuel, some of it damaged, some of it whole”…
Experts will use elementary particles bombarding the Earth to try to determine the location of melted nuclear fuel at the troubled Fukushima Daiichi nuclear power plant.
The project is aimed at finding clues as to the location of the melted fuel, a step that is indispensable to its removal from the damaged reactors, in order to continue with decommissioning work.
Three reactors at the plant suffered meltdowns following the massive earthquake and tsunami that struck the area in March of 2011. Extremely high radiation levels have been preventing experts from locating and determining the state of the melted fuel.
The experts will soon make use of a type of elementary particle called the muon to get a peek inside the reactors.
Workers wearing protective gear used a crane on Monday to install an observation device outside the Number 1 reactor building. The time they could devote to the task was limited, since radiation levels outside the reactor building are as high as 500 microsieverts per hour.
Muons are created when cosmic rays from space collide with the Earth’s atmosphere. Scientists say about 10,000 muons per square meter reach the Earth’s surface every minute.
Experts hope that observing the particles passing through the reactor building will create images of the nuclear fuel, in the same way an X-ray works.
After workers install another device at the Number 1 reactor on Tuesday, experts will conduct observations until March. It is believed that almost all the fuel in the reactor has melted and fallen down.
Experts also plan to use muons in a different way to probe the Number 2 reactor.
Fumihiko Takasaki, professor emeritus with the High Energy Accelerator Research Organization, led the development of the observation devices.
He said the project, which was started soon after the disaster happened, is finally being used at the plant. He said he hopes the technology will help with the decommissioning of the reactors by determining whether the fuel is still in them.
The operator of the Fukushima Daiichi nuclear power plant says a plan to fill in underground tunnels at the defunct facility will be delayed by 2 weeks.
TEPCO officials announced the new schedule at a meeting with the Nuclear Regulation Authority, or NRA, on Monday. The new timetable will start late this month.
TEPCO had initially planned to remove highly-radioactive water from the tunnels after building an ice wall to stop the water from leaking out of reactor buildings.
The workers poured cement into the tunnels while draining contaminated water. But blocking the water was not successful as it continued to flow through the buildings.
The officials said in the new plan, they will fill in areas where unblocked tunnels and reactor buildings join to stop the tainted water from seeping out.
NRA regulators mostly approved the plan. They will continue to probe what else is necessary to do.
The setback for water blocking effort is likely to affect the plan to build the ice wall.
TEPCO officials say the plan is already 2 weeks to a month behind schedule due to a fatal accident at the plant.
They say they do not yet know how the latest delay will affect the whole decommissioning project. They are still studying the next steps they need to take.
HITACHI, IBARAKI PREF. – A snakelike robot designed to examine the interior of one of the three meltdown-hit reactors at the Fukushima No. 1 nuclear power plant is ready to begin its expedition.
Assessing the damage in the reactors is a crucial step in decommissioning the poorly protected plant, which was crippled by core meltdowns triggered by the Great East Japan Earthquake and tsunami in March 2011.
Remote-controlled robots are essential for the job because the radiation in the reactors chambers is so high it would kill any person who got close.
Using information gathered by the robot, Tokyo Electric Power Co., the plant operator, plans to repair the damaged chambers enough so they can be filled with water in preparation to remove the melted radioactive debris, an operation planned to begin in about a decade.
The 60-cm-long robot, developed by electronics giant Hitachi and its nuclear affiliate Hitachi-GE Nuclear Energy, was demonstrated this week at a Hitachi-GE facility northeast of Tokyo. It is expected to enter the No. 1 reactor as early as April, officials said.
It has a lamp at the front and is designed to crawl like a snake through a 10-cm-wide pipe into the containment vessel. From there it must dangle and descend onto a platform just below the reactor core’s bottom, an area known as the pedestal.
There, the robot is to transform into a U-shaped crawler and capture live images and temperature and radiation levels and transmit them to a control station outside the building.
Expectations for the robot probe are high after earlier efforts at assessment met with limited success.
“Depending on how much data we can collect from this area, I believe (the probe) will give us a clearer vision for future decommissioning,” Hitachi-GE engineer Yoshitomo Takahashi said.
After its exploratory trip, which will make the robot extremely radioactive, technicians plan to store it in a shielded box. They have no plans to reuse it.
Different robots must be designed for each reactor, since each is slightly different.
According to computer simulations, all of the fuel rods in unit 1 probably melted and pooled at the bottom of the containment chamber, but there had been no way of confirming that until now.
A brief fiberscope observation conducted in 2012 produced images that were scratchy and of limited use.
To assess the debris at the bottom of the damaged reactor chambers, which are usually filled with water, an amphibious robot is being developed for deployment next year.
The damage from the melted fuel burned holes in the reactors, thwarting efforts to fill them with cooling water. As a result, water must be pumped into them continuously, producing an endless stream of radiation-contaminated water that is hampering the plant’s cleanup process.
Members of Fukushima Saisei no Kai (Resurrection of Fukushima) drive through Iitate village to measure radiation levels on Jan. 28.
February 08, 2015
On a recent day in late January, a minicar departed from the Iitate village office in Fukushima Prefecture with stickers attached that said, “We are driving slowly because we are measuring radiation levels.”
The vehicle, operated by Fukushima Saisei no Kai (Resurrection of Fukushima), a local residents’ nonprofit organization, is equipped with GPS and radiation measurement equipment, allowing it to record locations and airborne radiation levels.
“Although the level has decreased considerably from immediately after the Fukushima nuclear accident, it is still high,” said Mitsukazu Sugiura, 65, the driver of the vehicle, on Jan. 28.
Distrust of the central government, a need to know to make future plans and a desire to maintain ties with neighbors have led to groups of residents around Fukushima Prefecture taking the initiative to monitor radiation levels on their own.
All of Iitate village, which is divided into 20 districts, has been designated as an evacuation zone.
While the village government measures radiation levels at two locations in each district, it has also commissioned Fukushima Saisei no Kai to conduct more detailed measurements.
The organization’s vehicle is driven by village residents who commute from where they have evacuated to, such as Minami-Soma or Fukushima cities.
Twice a month in each district, group members conduct measurements along almost all areas along roads where residents lived.
Average radiation levels for each 100-meter-square area have been posted on the group’s website.
The near-term goal of the Iitate village government is to encourage residents to return with the planned lifting in March 2016 of the evacuation order. However, residents cannot erase concerns about radiation effects on their health as well as questions about the possibility of resuming agriculture.
Local farmer Muneo Kanno, 64, established Fukushima Saisei no Kai three months after the March 2011 accident at the Fukushima No. 1 nuclear power plant along with scientists and friends. Kanno felt that scientific data would be needed to decide whether to return to Iitate and resume farming.
“In order to tie it with the resurrection of the community, it will be important to have local residents directly involved,” he said.
Residents of the Okubo-Yosouchi district in central Iitate began measuring radiation levels near their homes and in the farm fields from 2013. The catalyst was the monthly meetings that were held for the 14 households in the hamlet that had gone their separate ways after the evacuation order was issued.
At those meetings, residents were curious about the radiation levels. However, some said the central government could not be trusted, so they decided they had to check for themselves what the radiation levels were.
Immediately after the nuclear accident, the residents were slow to evacuate because they were not informed by the central government about the estimated spread of radioactive materials.
Masuo Nagasho, 67, a former village government employee, suggested residents conduct their own measurements.
“The attraction of the village was the people,” he said. “What I most regretted was the destruction of ties between people and the life of the community that had led before to working together for festivals and rice planting.”
In 2014, the monitoring effort spread to the entire district, which has about 70 households. The measurement has provided the perfect opportunity for residents to maintain their neighborly ties by having lunch together. The meals are provided by a local women’s group.
TARGETING WATERS OFF NUCLEAR PLANT
Another citizens’ group, Umilabo, has been monitoring radiation levels off the coast of the crippled Fukushima No. 1 nuclear plant since November 2013.
One member, Riken Komatsu, 35, works at a fishcake manufacturing plant in Iwaki. He was born and grew up in the area, but when customers asked about the safety of the fish being used, he could only pass along data collected by Tokyo Electric Power Co., the Fukushima No. 1 plant operator, and the Fukushima prefectural government.
“I wanted to go out into the ocean and pass along data I was certain about,” Komatsu said.
He and other fishing enthusiasts began the project to collect soil from the seabed and fish, which were taken to the local aquarium for measurement of the amount of radioactive materials they contained.
In November 2014, 10 flatfish were caught about 1.5 kilometers off the coast from the nuclear power plant. Radioactive materials tend to accumulate in flatfish because it lives near the seabed. Although radioactive cesium was detected in five of the 10 flatfish, the concentration was less than half of the standard in the Food Sanitation Law of 100 becquerels or less per kilogram.
There has been no detection of radioactive materials for almost all of the fish born after the nuclear accident.
In the Oguni neighborhood of Date city’s Ryozenmachi district, a resident’s group began taking airborne radiation level measurements from six months after the nuclear accident. Data for each 100-meter-square area were listed on a map, and the information has been updated annually since.
“The radiation has no color or smell, but the map has enabled us to see it,” said Soyo Sato, 66, who heads the group.
The neighborhood has a mix of households that were designated for evacuation because of high radiation levels as well as those that were not so designated. Residents who were exempt from the designation used the data on the map to argue that there was very little difference in radiation levels with areas designated for evacuation.
That led to a settlement with TEPCO for compensation levels that were close to those offered to residents living in the designated areas.
Hideki Ishii, a project associate professor of landscape architecture at Fukushima University, has provided support for self-monitoring efforts.
“When residents see the actual data for their community that they collected, they will think more seriously about whether people can live there and if the compensation levels offered are appropriate,” Ishii said. “It also fosters the ability to not only think about the current situation, but also the future.”
Someone somewhere commented:
“The Evacuate-Fukushima-Now battle cry hasn’t been thought out too well because it fails to recognize the moral questions that arise when non-victims speak for the victims—thinking that it is their job to rescue people who have decided to stay and haven’t asked for help.”
I wish to answer here to that partial judgment. Erroneous because that judgment was made much afterwards competely out of its historical chronological perspective:
The Evacuate Fukushima Now battle cry at the start of the Fukushima catastrophe was well justified and absolutely right in itself.
It was very soon countered by the Japanese government orchestrating a gigantic campaign about « decontamination » thru all the media, constructed and directed by government contracted big advertising-PR companies, playing very well on all the « furuisato » (hometown attachment) feelings of the Fukushima people ; their attachment to their lands, to their own history, to their own Fukushima dialect and cultural traditions, to their family ties etc., brainwashing the people that after a possible-to-be-made-decontamination program paid by government everyone everything would go back to the life of before, normal as before.
Due to that government huge mediatic campaign to control the situation, to keep the people to stay, promising them full decontamination, lying to them continuously that everything in Daiichi was under control, just a very local technical problem to resolve, they cut in the bud any possible evacuation idea.
The Government well-orchestrated mediatic campaign knew very well how to play on the Furuisato feelings of most the Fukushima people to manipulate them, resulting in the majority of people in Fukushima willingly participating in the brainwashing and PR campaign. The support Fukushima campaign came from the bottom up as much as from the government.
It is the same in every contaminated community: the deniers always outnumber those who understand the danger and want out. They get intimidated, bullied and silenced. All one can do is leave at one’s own expense.
To not forget that the majority of those Fukushima people did not have the financial means on their own to abandon everything behind to attempt to evacuate adventurously with their whole family in another prefecture, and that the government did all it could to deter them from evacuating, the people losing any possible damage claims if evacuating out of the prefecture, their properties devalued, their house credits still to be paid.
Due to all this the Evacuate Fukushima battle cry became very soon an empty battle cry, the Japanese anti-nuclear movement itself abandoned it very early to the benefit of the other battle-cries of « Kodomo wo Mamore » (protect the children), «Genpatsu Iranai » (we don’t need nuclear) and « Saikado hantai » (We are against the restart of nuclear plants).
The « Evacuate Fukushima Now » battle-cry was absolutely right, it was so damn right that the Japanese government spent millions on a mediatic campaign to cut it in the bud, to defeat that idea, to keep the people from evacuating, to make them stay by all means living with radiation, in contaminated environment. To after 4 years push now the evacuees of the 20kms evacuated zone to return to live in high radiation.
Japan aims to restart nuclear reactor in June: sources BY AARON SHELDRICK TOKYO Fri Feb 6, 2015 (Reuters) – Japan’s government is aiming to restart a nuclear reactor by around June following a lengthy and politically-sensitive approval process in the wake of the Fukushima disaster, sources familiar with the plans said……..
But the move would be controversial in a nation where most oppose nuclear power, with memories still fresh of the worst atomic crisis since Chernobyl in 1986……..
Kyushu Electric Power Co will be given the greenlight to restart two nuclear units in southwestern Japan, with June penciled in for the first unit, according to three sources familiar with the government’s thinking. They declined to be identified as they were not authorized to speak with media.
By June, Japan’s Nuclear Regulatory Authority is expected to have completed the final checks and appraisal of the reactors at Kyushu Electric’s Sendai station, letting Abe give the final go-ahead after local authority approval late last year.
A June restart would also mean local elections scheduled for April would be out of the way, giving the government some leeway to take such a potentially unpopular step…….
“We urge the government to take into full consideration the tremendous suffering from the nuclear power plant accident and make sure that future policy ensures the safety and peace of mind of all citizens,” Fukushima Governor Masao Uchibori said, when asked about restarts………
This effort to concrete in the unit 3 trench had not been previously announced and the area had not had any unusually high levels of contamination compared to other areas.
TEPCO concreted the unit 3 trench in some unannounced work at Fukushima Daiichi.
Today’s chedule from 10:00 AM to 13:42PM they unloaded 100m3 of concrete into the Unit 3 trench.
The restart of a nuclear power plant in southwestern Japan may not come until May at the earliest, due to a procedural reason.
In September, 2 reactors at the plant in Satsuma Sendai City in Kagoshima Prefecture became the first in Japan to meet new, tougher government regulations introduced after the 2011 nuclear disaster in Fukushima. Later, the governor of Kagoshima gave consent to Kyushu Electric Power Company to restart them.
The utility still needs approval from the Nuclear Regulation Authority for technical documents. It told the authority on Thursday that preparing them will take 2 or 3 months longer than expected because the authority says many revisions are needed.
One of the documents explains in detail facility designs for the plant’s Number 1 reactor. The company originally planned to submit it in December. It now says it will take until the end of February, due to the need to provide more detailed data and explanations on earthquake resistance.
The utility says it will submit by the end of March a separate document describing designs for facilities that are shared with the Number 2 reactor.
The restart may not come until May or later, possibly the summer, pending the regulator’s approval of the documents and onsite inspections.
All of Japan’s commercial nuclear reactors remain offline.
The study reviewed foods testing for cesium 137 contamination and also strontium 90 contamination.
Official assumptions had been than there was a set ratio of cesium 137 to strontium 90 across all foods.
This is even more problematic as testing for actual strontium 90 in foods is done less often due to the complexity of the testing method.
What was found is that over time the ratio of strontium 90 in foods had increased.
A new study in the journal Environmental Science & Technology looked at governmental food testing in Japan.
In an unprecedented food monitoring campaign for radionuclides, the Japanese government took action to secure food safety after the Fukushima nuclear accident (11 March 2011). In this paper we analyze a part of the immense data set, in particular radiocesium contaminations in food from the first year after the accident. Activity concentrations in vegetables peaked immediately after the campaign had commenced, but they decreased quickly, so that by early summer 2011 only few samples exceeded the regulatory limits. Later, accumulating mushrooms and dried produce led to several exceedances of the limits again. Monitoring of meat started with significant delay, especially outside Fukushima prefecture. After a buildup period, contamination levels of meat peaked by July 2011 (beef). Levels then decreased quickly, but peaked again in September 2011, which was primarily due to boar meat (a known accumulator of radiocesium). Pre-Fukushima 137Cs and 90Sr levels (resulting from atmospheric nuclear explosions) in food were typically lower than 0.5 Bq/kg, whereby meat was typically higher in 137Cs, and vegetarian produce was usually higher in 90Sr. The correlation of background radiostrontium and radiocesium indicated that the regulatory assumption after the Fukushima accident of a maximum activity of 90Sr being 10% of the respective 137Cs concentrations may soon be at risk, as the 90Sr/137Cs ratio increases with time. This should be taken into account for the current Japanese food policy as the current regulation will soon underestimate the 90Sr content of Japanese foods.
According to NRA (Nuclear Regulation Authority), Last December’s fallout level of Cs-134/137 increased 3.7 times much as December 2013 in Fukushima.
From their report “Readings of environmental radioactivity level by prefecture” released on 1/30/2015, the fallout level in Futaba county was 6,200 MBq/km2・month in December of 2014.
It was 1,657 MBq/km2・month in December of 2013.
The readings of other areas in Fukushima prefecture are not reported.
NRA hasn’t made any announcement on this rapid increase in fallout level.
At 8:00 — Already, 85 children have had surgeries for thyroid cancer, there are 112-113 children who are suspected of having cancer. When children get cancers it progresses very quickly. The former person in charge of health, Yamashita Shunichi, said it would be only a 1 in a million chance of children getting any kind of cancer because of radiation. But he was lying. Right now, it’s like 1 in 3,000 — it’s an epidemic… The head of the National Cancer Research Center estimated right now in Fukushima the rate of cancer has gone up 61 times. And yet the gov’t and also the hospitals related to the gov’t are saying this is not because of radiation… How long does the gov’t think that we’ll be silent about this? In light of this epidemic, my anger will never die down. And then to think about the parents of the small children – how worried they must be.
At 12:00 — It’s not only children. There are many things happening to adults as well. Increased rates of thyroid cancer, heart attacks, leukemia, cataracts – many, many health problems, where they are wondering… there’s something definitely wrong.
At 16:00 — I can’t forgive the gov’t, they’re murderers. This is definitely a holocaust.
At 20:00 — Media won’t report on it. Everything’s just being swept under the rug.
At 26:00 — A TV program called ‘Hodo Station’… they went to Fukushima City to interview people and they also came to my clinic… The director that made this program also made a follow up show and contacted one of the interviewees telling her, ‘We’ll be airing it soon.’ But before it was aired, it was taken off the program. This director died. This director apparently told one of the interviewees, ‘If you do hear that I died, please believe that it was not a suicide, no matter what you might hear.’ There is no truth in the media in Japan today. There are all sorts of these mysterious events happening that are still unexplained and uninvestigated.
At 43:00 — Even today the gov’t is insisting the rise in pediatric thyroid cancer rates are not due to the accident…Why are they being so insistent? It’s because the moment they admit the reality of what’s going on, then they obviously can’t restart any of the nuclear plants and must change their entire nuclear policy.
Carole Hisasue, translator (at 1:15:00): It’s disappeared from the media, it’s disappeared from people’s consciousness. There’s this big culture of denial going on outside of Fukushima. They want to pretend like it never happened. I can’t talk to my own family about radiation contamination… They don’t want to hear it. They go, ‘You don’t understand because you don’t have to live here, we have to live here.’… It’s like ‘see no evil, hear no evil, speak no evil’… just trying to ignore it and pretend life is the way it was before 3/11. It’s frightening, it’s very very frightening… [My sister-in-law] is completely brainwashed by the gov’t who says, ‘Oh no, it’s fine, fine, fine’… she believes it, even though her son suffers from a lot of nosebleeds — and I think that’s a serious problem. If I mention it to her, or even to my own mother, they get very offended. They go, ‘Oh no, no. He’s always been like that. It’s nothing to do with radiation.’ Talk about denial, it just hurts my heart.
Sources:
Youtube: Report From Fukushima And The Abe Government Expansion And Export Of Nuclear Plants
Enenews: Cancer epidemic underway in Fukushima — Rates up 6,000% says head of cancer research center — “This is definitely a holocaust… everything’s being swept under the rug” — “Very, very frightening… my family members are brainwashed”
Tohoku Electric Power Company says it has found more than 4,000 improper entries in its inspection records about one of the reactors at its Onagawa nuclear power plant.
The initial inspection was held to check a wide range of facilities at the plant’s No. 2 reactor after the great earthquake that hit northeastern Japan. The operator is hoping to restart the reactor about 100 kilometers north of the crippled Fukushima Daiichi plant.
But Japan’s Nuclear Regulation Authority pointed out last year that Tohoku Electric’s inspection was lax and the firm was re-examining the inspection records on the No. 2 reactor.
Company officials said at a news conference on Wednesday that the utility has scrutinized all the inspection records for the reactor since August 2011.
They said in some cases workers entered “no problem” for parts that didn’t exist, citing the example of monitoring equipment for a valve which was not there.
In other cases, incorrect product types and serial numbers were left untouched. They say there were 4,188 errors in total.
Managing Director Takao Watanabe apologized to people in the region for causing concern, although he asserted the improper entries will not lead to any safety problems.
The company says it will also check the inspection records for the No.1 and No. 3 reactors.
Pressure exerted by tectonic plate movement off Tohoku that triggered the 2011 earthquake and tsunami has returned to pre-disaster levels, seismologists say.
“Large earthquakes might occur more randomly distributed in time than conventionally expected,” said Bogdan Enescu, an associate professor at the University of Tsukuba.
Researchers from the university and Switzerland-based Eidgenoessische Technische Hochschule analyzed seismic data collected by the Japan Meteorological Agency since 1998.
As part of the study, the team calculated b-values, a ratio comparing the occurrence of small earthquakes in a specific area with larger ones.
Because the b-values decline to under 1 when the frequency of large quakes increases, they assumed values of less than 1 are indicative of high plate stress in the areas being studied.
Although readings in the region at the center of the 2011 earthquake hovered around 0.8 to 0.9 from 1998 until 2005, the b-values dropped to around 0.6 to 0.7 in mid-2005. Those figures then surged to 1 or higher after the Great East Japan Earthquake of March 11, 2011.
But the b-values started to decline again around 2013, and returned to around 0.8 by the fall of 2014–almost the same level registered prior to the magnitude-9.0 quake.
“Observing b-values could be useful in improving the accuracy of massive earthquake forecasting,” said Enescu.
The findings were published in the British scientific journal Nature Geoscience on Feb. 3.
