Ikata Nuclear Power Plant is located in Ehime Prefecture in Shikoku, across from the Bungo Channel that separates Kyushu and Shikoku.
Ikata Nuclear Power Plant with pressurized water reactors by Mitsubishi Heavy Electric sits extremely close to Japan’s Median Tectonic Line, the largest fault in Japan, part of which is active.
MATSUYAMA (Kyodo) — Economy, Trade and Industry Minister Hiroshige Seko on Saturday inspected a recently restarted reactor at the Ikata nuclear power plant in western Japan to assess the safety measures there.
Seko visited an observation deck that overlooks the entire complex of Shikoku Electric Power Co.’s plant in Ehime Prefecture, as well as a facility to store spent nuclear fuel in the radiation-controlled area and other locations.
Seko was briefed on a system to provide electricity in the event of earthquakes and other emergencies by Seizo Masuda, the chief of the plant, and expressed satisfaction at the multiple backups available.
The No. 3 reactor at the Ikata plant was reactivated on Aug. 12, having cleared a set of safety requirements imposed in the wake of the Fukushima Daiichi nuclear power plant disaster in 2011.
The 890-megawatt reactor shifted to commercial operation on Sept. 7 following final checks by the Nuclear Regulation Authority. The unit had not operated since it was taken off-line in April 2011 for regular checks.
Some snags occurred around the time of its reactivation, including a problem with a pump for the reactor’s primary cooling water and a leakage in a drainage pipe in related equipment.
The reactor is currently the sole unit in operation in Japan running on plutonium-uranium mixed oxide fuel, which contains plutonium extracted from reprocessing spent fuel.
http://mainichi.jp/english/articles/20161015/p2g/00m/0dm/070000c
October 15, 2016
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Japan | Earthquakes, Ikata NPP, Mox Fuel |
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A powerful 6.4-magnitude earthquake rocked Japan some 230km southeast of the country’s capital, Tokyo, at a depth of 10km on Thursday night, the US Geological Survey (USGS) reported on its website.
Japan’s Meteorological Agency reported that the earthquake “has caused no damage to Japan,” while adding that “slight sea-level changes in coastal regions” may be observed.
No immediate tsunami warning has been issued.
Small tremors were reportedly felt in nine Japanese prefectures, including in Fukushima and Tokyo.
Japan is located in a seismically active region at the juncture of three major tectonic plates: North American, Pacific and Philippine Sea.
https://www.rt.com/news/360331-tokyo-southeast-quake-reaction/#.V-R_nRi_Fis.facebook
http://www.jma.go.jp/en/quake/20160921012819495-210122.html
http://www.jma.go.jp/en/quake/20160923092111495-230914.html
A whole lot of shallow quakes in the trench
http://www.japanquakemap.com/week
September 23, 2016
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Japan | Earthquakes |
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Succession of earthquakes in the Sanriku Oki area (epicenter in the ocean off Fukushima) yesterday and today (5 or 6 earthquakes of magnitude ranging from 5.3 to 6)
Seismotectonics of Japan and Vicinity
The North America plate, Pacific plate, Philippine Sea plate, and Eurasia plate all influence the tectonic setting of Japan, Taiwan, and the surrounding area. Some authors divide the edges of these plates into several microplates that together take up the overall relative motions between the larger tectonic blocks, including the Okhotsk microplate in northern Japan, the Okinawa microplate in southern Japan, the Yangzee microplate in the area of the East China Sea, and the Amur microplate in the area of the Sea of Japan.
The seafloor expression of the boundary between the Pacific and North America plates lies 300 km off the east coasts of Hokkaido and Honshu at the Kuril-Kamchatka and Japan trenches. The subduction of the Pacific plate beneath the North America plate, at rates of 83-90 mm/yr, generates abundant seismicity, predominantly as a result of interplate slip along the interface between the plates. The 1958 M 8.4 Etorofu, 1963 M 8.6 Kuril, 2003 M 8.3 Tokachi-Oki, and the 2011 M 9.0 Tohoku earthquakes all exemplify such megathrust seismicity. The 1933 M 8.4 Sanriku-Oki earthquake and the 1994 M 8.3 Shikotan earthquake are examples of intraplate seismicity, caused by deformation within the lithosphere of the subducting Pacific plate (Sanriku-Oki) and of the overriding North America plate (Shikotan), respectively.
At the southern terminus of the Japan Trench the intersection of the Pacific, North America, and Philippine Sea plates forms the Boso Triple Junction, the only example of a trench-trench-trench intersection in the world. South of the triple junction the Pacific plate subducts beneath the Philippine Sea plate at the Izu-Ogasawara trench, at rates of 45-56 mm/yr. This margin is noteworthy because of the steep dip of the subducting Pacific plate (70° or greater below depths of 50 km depth), and because of its heterogeneous seismicity; few earthquakes above M 7 occur at shallow depths, yet many occur below 400 km. The lack of large shallow megathrust earthquakes may be a result of weak coupling at the plate interface, or simply a reflection of an incomplete earthquake catalog with respect to the length of typical seismic cycles.
The northernmost section of the Philippine Sea plate shares a 350 km boundary with the North America plate that runs approximately east-west from the Boso Triple Junction towards the Izu Peninsula. This short boundary is dominated by the subduction of the Philippine Sea plate beneath Japan along the Sagami Trough, but also includes small sections of transform motion.
The subduction of the Philippine Sea plate under the Eurasia plate begins at the Suruga Trough, immediately southwest of the Izu peninsula. In the northern Tōkai, Tonankai and Nankai sections of this subduction zone, historical data indicate M 8+ earthquake recurrence intervals of 100-150 years. The Tonankai and Nankai sections last ruptured in M 8.1 earthquakes in 1944 and 1946, respectively, while the Tōkai section last broke in 1854. In the 1980’s studies began to forecast the imminence of a large earthquake in the Tōkai region, and warned of its potential impact on the cities of Tokyo and Yokohama (the two largest cities in Japan); to date, the expected event has not occurred.
The boundary between the Philippine Sea and Eurasia plates continues south and southwestwards from the Suruga Trough, extending 2000 km along the Nankai and Ryukyu trenches before reaching the island of Taiwan. Along the Ryukyu Trench, the Philippine Sea plate exhibits trench normal subduction at rates increasing from 48 mm/yr in the northeast to 65 mm/yr in the southwest. Convergence and the associated back-arc deformation west of the oceanic trench creates the Ryukyu Islands and the Okinawa Trough. The largest historic event observed along this subduction zone was the M 8.1 Kikai Island earthquake in 1911.
In the vicinity of Taiwan the structure of the Philippine Sea: Eurasia plate boundary and the associated pattern of seismicity becomes more complex. 400 km east of Taiwan a clockwise rotation in the trend of the margin (from NE-SW to E-W), paired with an increase in subduction obliquity creates a section of the plate boundary that exhibits dextral transform and oblique thrusting motions. South of Taiwan the polarity of subduction flips; the Eurasia plate subducts beneath the Philippine Sea plate. Debate surrounds contrasting models of the plate boundary position between the zones of oppositely verging subduction, and the boundary’s relation to patterns of seismicity. Many studies propose that crustal thickening causes the majority of regional seismicity, while others attribute seismicity to deformation associated with subduction. Another resolution proposes a tear in the Philippine Sea plate and a complex assortment of subduction, transform, and collisional motion. All the models concede that seismicity around the island of Taiwan is anomalously shallow, with few earthquakes deeper than 70km.
While there are no instances of an earthquake M>8 in the modern record, Taiwan and its surrounding region have experienced eight M>7.5 events between 1900 and 2014. The dominance of shallow M<8 earthquakes suggests fairly weak plate boundary coupling, with most earthquakes caused by internal plate deformation. The 1935 M 7.1 Hsinchu-Taichung earthquake and the 1999 M 7.6 Chi-Chi Earthquake both exemplify the shallow continental crust thrust faulting that dominates regional seismicity across the island. A major tectonic feature of the island is the Longitudinal Valley Fault, which ruptures frequently in small, shallow earthquakes. In 1951, the Longitudinal Valley Fault hosted twelve M≥6 events known as the Hualien-Taitung earthquake sequence.
Large earthquakes in the vicinity of Japan and Taiwan have been both destructive and deadly. The regions high population density makes shallow earthquakes especially dangerous. Since 1900 there have been 13 earthquakes (9 in Japan, 4 in Taiwan) that have each caused over 1000 fatalities, leading to a total of nearly 200,000 earthquake related deaths. In January 1995 an earthquake that ruptured a southern branch of the Japan Median Tectonic Line near the city of Kobe (population 1.5 million) killed over 5000 people. The 1923 Kanto earthquake shook both Yokohama (population 500,000, at that time) and Tokyo (population 2.1 million), killing 142,000 people. The earthquake also started fires that burned down 90% of the buildings in Yokohama and 40% of the buildings in Tokyo. Most recently, the M9.0 Tohoku earthquake, which ruptured a 400 km stretch of the subduction zone plate boundary east of Honshu, and the tsunami it generated caused over 20,000 fatalities.
Sources:
Magnitude 5.3 quake hits off north-eastern Japan
http://www.straitstimes.com/asia/east-asia/magnitude-53-quake-hits-off-northeastern-japan
M6.0 – 170km ENE of Miyako, Japan
http://earthquake.usgs.gov/earthquakes/eventpage/us10006ffg#executive
Earthquake Information
http://www.jma.go.jp/en/quake/20160821013226395-210128.html
August 21, 2016
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Japan | Earthquakes, Off Fukushima, Sanriku Oki |
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Protesters rally against the restart of the Ikata nuclear power plant in the town of Ikata, Ehime Prefecture, on July 24
MATSUYAMA, EHIME PREF. – When two earthquakes of magnitude 6.5 and 7.3 struck Kumamoto Prefecture in April, the shock was felt not only in Kumamoto but also about 170 km away, in the small town of Ikata, Ehime Prefecture, home to a nuclear power plant.
For years, residents had been told that the Median Tectonic Line, which runs from Kyushu to Honshu and passes just 5 km away from the Ikata plant, was not active and that there was nothing to worry about. After the April quakes, no abnormal atomic activity was reported, but residents are now worried a large quake in the area, followed by tsunami, could not only damage the plant but also make evacuation from the peninsula Ikata lies on impossible.
The restart of Ikata reactor 3, slated for Aug. 12, has put those concerns in sharp focus and raised questions about just how realistic evacuation will be in the event of a natural disaster — especially an earthquake that sends a tsunami churning toward the nearly 124,000 residents living within 30 km of the plant.
“The official evacuation plans assume emergency vehicles will have a certain degree of access to the low-lying roads on the peninsula, which are often only a few meters above sea level. But what happens if the roads are flooded by tsunami or damaged beyond use due to landslides? There are about 5,000 people on the peninsula living on the western side of the Ikata plant who might be cut off from escaping by land to the designated evacuation areas lying east of the plant,” said Tsukasa Wada, an Matsuyama-based antinuclear activist who is fighting to keep the Ikata plant closed.
In granting permission last year to restart Ikata’s No. 3 unit, Ehime Gov. Tokihiro Nakamura dismissed such concerns, saying the rock formations around the plant are strong. But the prefecture has designated 194 areas in the town of Ikata as highly susceptible to landslides.
To get to the Ikata plant from Matsuyama by car or bus also involves passing through a series of tunnels. Tunnel construction experts have testified in past lawsuits involving the plant that many of the tunnels are weak, suggesting that an earthquake could cause cave-ins, rendering them unusable.
The central government and the prefecture are aware that land evacuations alone could prove impossible. So the official plans also include evacuations by air and, most controversially, by sea. The plans assume there is time to evacuate by sea before radiation from the plant spreads, and that ships can dock at nearby ports even if the peninsula’s main access road has been destroyed by a quake, tsunami, or both.
The April quakes in Kumamoto led to fears in neighboring Kagoshima Prefecture about running the two reactors at Kyushu Electric Power Co.’s Sendai plant. That helped fuel the election last month of Gov. Satoshi Mitazono, who is against nuclear power and has said he’ll try to shut down the two Sendai reactors.
But in late July, Ehime Gov. Nakamura insisted that, despite the results in Kagoshima and growing concerns in Ehime, where an opinion poll by the daily Ehime Shimbun in July found 54 percent of respondents opposed to the restart, he had no intention of canceling or postponing it to revisit the issues of the plant’s safety or the evacuation plans.
“The conditions are different in each of the different areas where nuclear power plants are located, as is the age of the reactors in each area and their structure. You can’t compare them. In particular, for the process leading up to restarts, the approach and system is different for each area, with different plans for evacuation,” Nakamura told reporters at a regular press briefing.
But even a Shikoku Electric Power Co. survey in late May and early June of nearly 28,000 households lying within 20 km of the Ikata plant showed that, compared with a similar survey last year, more people were skeptical of safety assurances and fewer were convinced of the need for nuclear power. Shikoku Electric admits that the Kumamoto earthquakes probably influenced this year’s results.
http://www.japantimes.co.jp/news/2016/08/05/national/far-reaching-quakes-put-ehimes-atomic-evac-plans-doubt/#.V6ZakzUnDIU
August 6, 2016
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Japan | Earthquakes, Evacuation Plan, Ikata NPP |
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Tokyo was struck by a third quake in four days on Jul 20, but there were no reports of damage or casualties.
TOKYO – Tokyo was struck by a third earthquake in four days on Wednesday, but there were no reports of damage or casualties.
The 5.0 magnitude jolt was felt in Tokyo and areas of eastern Japan at 7.25am (5.25am Thailand time), the US Geological Survey said.
It was the third quake to shake the capital’s high-rise buildings in recent days — following a 4.8 magnitude quake on Tuesday and one of 5.0 on Sunday — but an official with the Japan Meteorological Agency said they weren’t a precursor of a major jolt.
“This is an area that sees frequent earthquakes” of a moderate size, Nariaki Ohkawara told AFP, adding that the latest quakes were part of that trend.
The epicentre of Wednesday’s quake was east of the capital in Ibaraki prefecture at a depth of about 44 kilometres, the USGS said.
There was no threat of a tsunami, the Japan Meteorological Agency said.
Japan sits at the junction of four tectonic plates and experiences a number of relatively violent quakes every year, but rigid building codes and strict enforcement mean even powerful tremors frequently do little damage.
A massive undersea quake that hit in March 2011 sent a tsunami barrelling into Japan’s northeast coast, leaving more than 18,000 people dead or missing, and sending three reactors into meltdown at the Fukushima nuclear plant.
In April, two strong earthquakes hit southern Japan’s Kumamoto prefecture followed by more than 1,700 aftershocks, and left 49 dead and caused widespread damage.
The country routinely holds emergency drills to prepare for a major jolt, and the government stepped up its disaster response in the wake of the 2011 devastation.
http://www.bangkokpost.com/news/asia/1039805/tokyo-jolted-by-third-quake-in-four-days
July 20, 2016
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Japan | Earthquakes, Tokyo |
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A former deputy chairman of the Nuclear Regulation Authority (NRA) sent the organization a letter of protest on July 14 demanding that an earthquake estimate for Kansai Electric Power Co. (KEPCO)’s Oi Nuclear Power Plant be recalculated, on the grounds that the official NRA estimate is well below that of KEPCO.
The former deputy chairman, Kunihiko Shimazaki, is a professor emeritus of seismology at the University of Tokyo. He had criticized the NRA’s estimate of the largest possible earthquake at the Oi plant in Fukui Prefecture as possibly being too low, and the NRA recalculated the estimate in a different manner but still deemed the projected earthquake as not posing a problem to the plant’s safety. In his letter of protest he wrote that he “could not accept the conclusion” of the NRA, and he called for another recalculation. He said he would hold a press conference on July 15 about the issue.
The NRA’s recalculated estimate was 644 gals, “gal” being a unit of acceleration. The estimate was below a KEPCO estimate of 856 gals. Shimazaki, in response to the figures, argues that the NRA’s calculation method is different from KEPCO’s and so produced a smaller number, and notes that the utility finalizes its estimate with additional calculation under stricter conditions, but the NRA has not done so. Shimazaki says that if the calculation was carried out in the same way as KEPCO has performed its estimate, the figure would come out to roughly up to 1,550 gals.
On July 13, a representative for the NRA’s secretariat acknowledged in a Mainichi Shimbun interview that the NRA’s calculation method differed from KEPCO’s, saying, “It’s only natural that there is a difference (in the calculation results).” The representative avoided giving a clear answer about whether it was right for the NRA to green light the plant by comparing results calculated in different methods.
Shinji Kinjo, the head of the agency’s public relations department, said, “If there is a request (for a recalculation), we will consider it sincerely.”
http://mainichi.jp/english/articles/20160715/p2a/00m/0na/001000c
July 19, 2016
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Japan | Earthquakes, Oi NPP, Quake estimate |
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20/04/2016
Kyushu Earthquake: “Lessons Not Learned From Fukushima” Report By Hiroko Aihara Fukushima Journalist
https://www.youtube.com/watch?v=exw3OzgXT_s
Fukushima independent journalist Hiroka Aihara talks about the failure to learn the lessons of Fukushima in the recent Kyushu earthquake in Japan. She also discusses how the government and the mass corporate media have refused to seriously cover the dangers of another Fukushima. Using the recently passed secrecy laws the government has repressed and silenced journalists. The Abe government has also said that everything has returned to “normality” and the Fukushima crisis is over. She reports that teachers have been told not to warn the students and their families of the continuing radiation dangers and use of the secrecy law to suppress information. She also discusses the growing militarization of Japan and the connection to the nuclear power program and industry.
The interview was done in Tokyo on April, 20, 2016
May 17, 2016
Posted by dunrenard |
Japan | Earthquakes, Fukushima Daiichi, Sendai NPP |
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On May 8, 2016 already more than 3 weeks have passed since the start of the earthquakes in Kumamoto and Kumatomoto prefecture, or they are still continuing. Below are the numbers from 14 to 28 April 2016. In just 14 days 1026 earthquakes from various magnitudes.
The Sendai nuclear plant in Satsumasendai, Kagoshima prefecture is just 147kms southward from Kumamoto. The whole Kyushu island is earthquake prone due to a main fault.
There is also a nice very active volcano in the vicinity, Sakurajima volcano, 72 kms from the Sendai nuclear plant, that is not counting the other eight volcanos on the island.
What you think, isn’t it the perfect place to build a nuclear plant?
Source:
http://www.fukushima-blog.com/2016/05/des-dommages-enormes-pour-la-vie-a-kumamoto.html
May 14, 2016
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Japan | Earthquakes, nuclear, Sendai NPP, Volcanos |
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The series of earthquakes that has hit central Kyushu since April 14 pose a variety of problems for us. The Meteorological Agency has explained that this chain of temblors is unprecedented in that the location of the hypocenter has moved. But one has to realize that it was only recently in the long history of the Earth that humans began their observations of seismic activities — and that it should come as no surprise if such a pattern of earthquakes had happened frequently in the past. In short, we humans know very little about the movements of the Earth. In Japan, earthquakes can hit anytime and anywhere.
Serious questions have been raised about the Abe administration’s response to the Kumamoto quakes. The first is why it didn’t try to listen to people who were suffering from the devastation brought by the temblors. The government’s call on evacuees to take shelter indoors following the initial quake that hit on April 14 drew the ire of the Kumamoto governor, who felt that officials in Tokyo didn’t understand the feelings of local residents.
The second question deals with the administration’s policy on the operation of nuclear power plants following the quakes. The government has declared that it won’t shut down the reactors at Kyushu Electric Power Co.’s Sendai plant in Kagoshima Prefecture — currently the sole nuclear plant in operation in this country. After clearing the Nuclear Regulation Authority’s screening of the plant for a restart, Kyushu Electric scrapped its plan to build a new facility with a seismically isolated structure that would serve as a command center in the event of an emergency. One of the assumptions in judging the safety of restarting the Sendai plant was that people would be able to evacuate the area by using bullet trains and the expressway network in case of a nuclear crisis. The Kumamoto quakes knocked those transportation means out of service, raising doubts about the workability of the evacuation scenario. That alone should be reason enough to halt the Sendai plant and rethink the safety measures. We need to consider carefully whether it is wise to have so many nuclear plants in this quake-prone country.
The third question is on the government’s intension to take advantage of the disaster to achieve its political goals — instead of focusing on relief for people in the disaster zone. Right after the temblors hit, Chief Cabinet Secretary Yoshihide Suga said the quakes highlighted the importance of amending the Constitution to give the government emergency powers to respond to such crises. Two U.S. Marine MV-22 Osprey tilt-rotor aircraft were dispatched to transport relief supplies in an apparent attempt at what Canadian author Naomi Klein calls the Shock Doctrine — taking advantage of a disaster to push a political agenda that has nothing to do with disaster response.
It is false to say that the government’s response to a disaster cannot proceed quickly because the Constitution does not grant emergency powers. Existing laws, such as the basic law on disaster response, provides a variety of powers that enables the government to take various actions if it wants to. Requesting the Osprey aircraft had nothing to do with providing relief for the disaster-hit people. I have heard nothing about Self-Defense Forces helicopters having been mobilized to their full capacity to transport relief goods to Kumamoto. I believe that using the Osprey was only a ploy to impress the public that strengthening defense cooperation between Japan and the United States under the Abe administration’s security legislation is helping ordinary citizens.
As memories of the 3/11 disasters fade away, the Abe administration is trying to divert public attention from the damage brought by the Fukushima nuclear disaster and create the impression that everything is back to normal. Its policy of restarting nuclear plants idled in the wake of the Fukushima crisis is part of such attempts. The Kumamoto quakes have exposed the questionable nature of Prime Minister Shinzo Abe’s politics.
When it comes to risks to people’s lives and their safety, natural disasters at home and the weakening of society as manifested by the aging and shrinking of the population pose a much more real threat than changes in the security environment surrounding Japan. The government is about to invest trillions of yen in Tokyo as it prepares to host the Summer Olympics in 2020. What significance does building a posh new national stadium in Tokyo and pursuing large urban redevelopment projects carry when people in other parts of the country suffer from the devastation caused by natural disasters? Can the government secure sufficient financial resources for reconstruction of the disaster-hit areas?
It is difficult to criticize the government when it is engaged in efforts to help people affected by a major disaster. But objections need to be clearly raised against any attempt to take advantage of a disaster to promote an unrelated political agenda. The mass media in particular bear a heavy responsibility to do that.
http://www.japantimes.co.jp/opinion/2016/05/09/commentary/japan-commentary/abes-questionable-handling-kumamoto-quakes/#.VzF9rr4TUaF
May 11, 2016
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Japan | Earthquakes, Sendai NPP |
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The epicenter was moving this way for one week time in Kumamoto earthquake.
680 plus earthquakes in just a few days.
But the Japanese Nuclear Regulation Authority declares that the Sendai nuclear plant is safe!!!
https://youtu.be/nzPfpT1cEJc
April 22, 2016
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Japan | Earthquakes, Sendai NPP |
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Japan’s atomic regulator will not shut down the nation’s only operating nuclear plant on earthquake-hit Kyushu island, despite concerns of a repeat of the Fukushima crisis.
The Nuclear Regulation Authority’s (NRA) decision came to light as the race to rescue survivors of the deadly earthquakes in southern Japan continued, with 10 still missing and the death toll rising to 42.
The Kumamoto region of Kyushu island was first hit last Thursday by a major tremor claiming nine lives which proved to be a foreshock to a bigger 7.3 magnitude earthquake striking early Saturday, killing a further 33.
Kumamoto city is located around 72 miles from Sendai nuclear power station, the only nuclear power plant which is currently in operation in Japan, operated by Kyushu Electric Power.
Last weekend, a group of writers and journalists joined forces to ask operators to immediately suspend operations at the Sendai plant in the aftermath of the earthquake, to avoid a repeat of the Fukushima crisis.
“Based on the experience at the Fukushima No. 1 nuclear power plant, it is clear to everyone that it would be too late if you waited for some abnormality to occur,” the group said in its request faxed to Kyushu Electric Power, according to the Asahi Shimbun.
However, the NRA on Monday held a special meeting with its commissioners, which resulted in Shunichi Tanaka, the chairman, to concluding that the Sendai plant, which has two reactors, was not endangered and should remain open.
The NRA announced plans to closely monitor the Sendai plant alongside three other nuclear power stations, including Genkai and Ikata on Kyushu island and Shimane, located further away on the main Honshu island.
The decision is likely to be greeted with widespread disappointment and protest in the disaster-hit region, with opposition to nuclear power running at an all time high in Japan.
The Kumamoto disaster comes five years after a major earthquake struck the northern Tohoku region of Japan on March 11, 2011, triggering a major tsunami, the world’s worst nuclear crisis in decades at Fukushima power plant.
News of the nuclear reactor situation came as rescue efforts continued across the Kumamoto region, which has been rattled by more than 500 aftershocks since last week’s earthquakes.
The United States military was due to join the relief efforts of 30,000-plus rescue service personnel who were rushing to provide food, water and shelter to more than 100,000 people who remained in shelters yesterday.
“There are still missing people,” Shinzo Abe, the prime minister, told parliament, as he outlined plans to declare the region a disaster zone as soon as possible. “We want to make further efforts to rescue and save people and prioritise human lives.”
Infrastructure was hit badly in the quakes, with the widespread destruction of roads and bridges, plus at least one mountain highway reportedly severed into two, causing concrete to tumble into a green valley below.
Around 1,000 homes were damaged in the two earthquakes, which also left around 80,000 households without electricity and 400,000 with no running water.
Transport is another challenge across the mountainous region, which suffered extensive mudslides in the earthquakes, with commercial flights to damaged Kumamoto airport cancelled and bullet train services suspended.
In addition to the race to find missing residents believed to be trapped under the rubble of collapsed buildings, food shortages were a key concern among rescue workers.
“Yesterday, I ate just one piece of tofu and a rice ball. That’s all,” the mayor of one of the areas affected told Reuters. “What we’re most worried about now is food. There’s no electricity or water, either.”
In a reflection of Kumamoto’s status as a manufacturing hub, the earthquakes have forced a string of major companies to temporarily close factories, resulting in parts shortages causing halted production elsewhere in Japan.
Toyota, the world’s biggest selling automaker, will suspend much of its plant production across Japan this week due to shortages of parts, while Honda also stopped production at its motorcycle plant near Kumamoto city.
Sony, the electronics giant, also halted production at its Kumamoto plant producing image sensors – used in Apple’s iPhone camera – as the damage was assessed, although there were full operations at other Kyushu plants making the sensors.
http://www.telegraph.co.uk/news/2016/04/18/japan-earthquakes-nuclear-regulator-refuses-to-shut-down-station/
April 21, 2016
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Japan | Earthquakes, nuclear safety |
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From April 14th to April 19th 2016, 665 earthquakes : 72 were above magnitude 4, 10 above magnitude 5, 6 above magnitude 6, 1 above magnitude 7. But the Japan Nuclear Regulation Authority tells us that the 3 nuclear plants in Southern Japan, the Sendai nuclear power plant, the Genkai nuclear power plant and the Ikata nuclear power plant, are safe depite more than 600 earhquakes within 5 days, out of which 89 were above magnitude 4.
The Japan Nuclear Regulation Authority tells us that the 3 nuclear plants in Southern Japan, the Sendai nuclear power plant, the Genkai nuclear power plant and the Ikata nuclear power plant, are safe depite more than 600 earhquakes within 5 days, out of which 89 were above magnitude 4.
Questions and answers: The Kumamoto earthquakes
The series of huge earthquakes and aftershocks that have been rattling wide parts of Kumamoto and Oita prefectures since Thursday have raised fears that other regions in the nation might be struck by similar jolts in the near future.
Here are some questions and answers on seismic activity in Japan:
What type of earthquakes struck Kumamoto?
The 2016 Kumamoto Earthquake is actually a series of quakes that are being caused by two plates slipping against each other along an active inland fault. The events take place at a relatively shallow depth and cause the destruction of bedrock.
It is the same type as the Great Hanshin Earthquake of 1995 that hit Kobe and surrounding cities, killing over 6,000 people.
In contrast, the Great East Japan Earthquake that hit the Tohoku region in 2011, was caused by accumulated stress resulting from one tectonic plate being forced underneath another, resulting in what is called a “megathrust quake.”
What is unique about the 2016 Kumamoto Earthquake?
Whereas often a huge temblor hits first, followed by smaller aftershocks, a number of strong quakes have occurred following the first magnitude-6.5 quake on Thursday. The shaking has affected much wider areas than other quakes in the past, experts said.
The magnitude-7.3 quake that according to the Meteorological Agency was the main tremor struck the region 1½ days after the first one.
Why did we see such big quakes in relatively rapid succession?
Experts say the reason is not entirely known.
Of the 2,000 active faults around Japan, some 100 are designated by the government as key active faults. The Futagawa and Hinagu faults, along which the recent quakes occurred, are among the 100 most active and dangerous faults in the country.
The central government has conducted research on these 100 active faults over the past decade or so but was not able to predict the quakes that took place in Kumamoto, said Hiroyuki Fujiwara, a seismologist at National Research Institute for Earth Science and Disaster Prevention.
Are the focal points of quakes moving or expanding?
Fujiwara said the magnitude-7.3 quake on Saturday caught seismologists by surprise as they thought the initial quake — which turned out to be a precursor for Saturday’s — was an isolated tremor in a small section of the Futagawa fault.
Other quakes then took place further east. Some researchers say quakes may take place in succession along the lines of long faults, but no solid theory to explain such a scenario has been found, Fujiwara said.
Are these quakes precursors for others, especially along the Median Tectonic Line — the largest fault running from central Honshu to Kyushu?
Experts are not sure.
“We can explain what has happened, but it’s really hard to say what will happen,” Fujiwara said.
Takeshi Sagiya, a professor at Nagoya University’s Disaster Mitigation Research Center and an expert on crustal movement, said it is too early to worry about such a scenario.
Sagiya said he is more concerned about the southwestern side of the Hinagu fault in Kumamoto, where seismic activities appear to have been spreading in recent days.
A level-6 quake on the Japanese intensity scale of 7 may hit the fault in the near future, Sagiya said.
Is the small eruption of Mount Aso on Saturday related to the quake?
The view of volcanologists, as well as the Meteorological Agency, has been that the eruption was not triggered by the Kumamoto quakes, as its characteristics are no different from small-scale eruptions that have taken place before.
“There is probably no causal connection” between the earthquakes and the eruption, Chief Cabinet Secretary Yoshihide Suga told a news conference Saturday. “But we will keep monitoring (the volcano).”
Are the quakes in Kyushu and the magnitude-7.8 quake that hit Ecuador over the weekend — the largest since 1979 — related?
Fujiwara said they are not.
“The two locations are so far away from each other it’s impossible to suspect a link,” he said.
Are nuclear power plants in Kyushu safe?
Many citizens and anti-nuclear activists have expressed concern over the nuclear power facilities in Kyushu, in particular the two reactors running at the Sendai power plant in Kagoshima Prefecture, the only commercial nuclear plant now in operation in Japan.
The Nuclear Regulation Authority, however, has maintained that the Sendai plant does not need to be shut down because the strongest temblor registered at the plant since Thursday night was 8.6 gal (a unit used in seismology to express the acceleration of an earthquake), far lower than the safety level that would trigger an automatic reactor shutdown.
The criteria was set between 80 to 260 gal, depending on the direction of a shake and the strength of key components in the Sendai reactors.
All other reactors have been stopped in the wake of the 2011 Fukushima meltdown crisis, while power companies have applied for the NRA’s safety checks to restart many other reactors under the new safety standards drawn up after the Fukushima crisis.
At the Genkai nuclear power plant in Saga Prefecture, the strongest of the recent shakes was 20.3 gal. The reactors at the plant have long been shut down, but had they been active, they would be automatically shut down with a temblor of between 70 and 170 gal.
The Ikata nuclear power plant in Ehime Prefecture, which is also undergoing safety checks, is right by the Median Tectonic Line. The three reactors there have not shown abnormal activity since the quakes, according to Shikoku Electric Power Co. and the Ehime Prefectural Government.
http://www.japantimes.co.jp/news/2016/04/18/national/questions-and-answers-the-kumamoto-earthquakes/#.VxZlvGPHyis
April 21, 2016
Posted by dunrenard |
Japan | Earthquakes, nuclear safety |
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I find it extraordinary that The Wall Street Journal, The New York Times, and The Washington Post have NOT run a single story in their print and online versions respectively of the earthquakes in Japan.
NHK reports that the second earthquake has been measured as a 7.3, with 41 people reported dead, and over 170,000 people evacuated. How can this story not be newsworthy? The airport and port are closed and so are major roads and the bullet train:
Scale of quake damage growing. NHK April 17, 2016,http://www3.nhk.or.jp/nhkworld/en/news/20160416_24/ The major earthquakes continuing to jolt areas in Japan’s southwestern region have so far left a total of 41 people dead.
Early on Saturday, a magnitude 7.3 earthquake hit areas in Kumamoto Prefecture in the Kyushu Region. It registered an intensity of 6-plus in the prefecture on Japan’s seismic scale of 0-to-7…Utility services have been disrupted. Hundreds of thousands of households are without electricity, gas and tap water.
Yesterday, on the front page of the print edition The Wall Street Journal ran a story “Japan’s Subzero Rates Cast Chill Over Markets” (4/15/2016, A1, A7) but there was no mention of the first earthquake anywhere in the print version of the paper.
Today’s WSJ print version has no mention at all of the earthquake in the front section and if there is any mention anywhere else its so buried I cannot find it.
The electronic version of the The New York Times from yesterday and today carry no mention that I can find of the earthquakes in Japan.
Today, The Washington Post has an article on “Why Mr. Obama Should Visit Hiroshima” (editorial) but like the Wall Street Journal and the New York Times, there is NO story on the earthquake that I can find in the electronic version delivered to my email.
I do NOT understand how two significant earthquakes in a geologically active zone with 41 people reported dead, over a hundred thousand evacuated, and an operational nuclear plant in the vicinity are not newsworthy, particularly given the risks are not over:
Seismic activity poses increasing risk. NHK,http://www3.nhk.or.jp/nhkworld/en/news/20160416_16/
Gen Aoki, the head of the agency’s earthquake and tsunami monitoring section, said the buildup in seismic activity means there’s an increased risk that buildings will collapse and mudslides will occur. He called on residents to stay safe.
It is my conclusion that there is a deliberate and concerted effort to help protect Japan’s economy from bad news, even during the occurrence of large earthquakes that pose the potential for catastrophic results.
I really don’t know what else to say. Its really unbelievable.
My thoughts go out to the people of Kyushu region whose tribulations are being disregarded in order to perpetuate myths about the global economy.
http://majiasblog.blogspot.fr/2016/04/unbelievable-censorship-of-japans.html?m=1
April 17, 2016
Posted by dunrenard |
Japan | Censoring, Earthquakes, nuclear |
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410 consecutive earthquakes since 14 April, including 162 of more than 3.5 magnitute, but the Japanese government keeps two reactors at the Sendai plant in operation ….
They have learned nothing from Fukushima.
Landslides sever National Route No. 57 in Minami-Aso, Kumamoto Prefecture, on April 16. Aso-ohashi bridge also collapsed.
410 quakes felt in Kyushu, 162 with magnitudes of at least 3.5
The number of earthquakes that could be felt by people reached 410 by 10 a.m. on April 17 following the start of seismic activity in Kumamoto Prefecture on April 14, the Japan Meteorological Agency said.
Quakes with magnitudes of 3.5 or larger accounted for 162 of the total by 8:30 a.m. on April 17, the largest among inland and coastal earthquakes since 1995. The previous high was set after the Chuetsu Earthquake in Niigata Prefecture in 2004.
“After the magnitude-7.3 earthquake that struck at 1:25 a.m. on April 16, the number of earthquakes increased sharply,” said Gen Aoki, director of the agency’s earthquake and tsunami monitoring division.
He urged people in the affected areas to remain alert amid the ongoing aftershocks.
“Earthquake movements are actively continuing in areas from Kumamoto Prefecture to Oita Prefecture,” Aoki said. “The soil could have become loose due to the rain that started to fall on April 16, so I want people to exercise caution against strong tremors or rain.”
http://www.asahi.com/ajw/articles/AJ201604170042.html
The No. 1 and No. 2 reactors at the Sendai nuclear power plant in Kagoshima Prefecture
Government lets Sendai reactors continue operations
The government on April 16 said there is no need to shut down two nuclear reactors in Kagoshima Prefecture, citing relatively low seismic movements around the nuclear plant.
Cabinet ministers met on April 16 to respond to the Kyushu earthquakes and discuss what to do with the No. 1 and No. 2 reactors of the Sendai nuclear power plant located in Satsuma-Sendai, Kagoshima Prefecture.
Environment Minister Tamayo Marukawa, who serves concurrently as state minister for nuclear emergency preparedness, mentioned the stricter safety standards implemented by the Nuclear Regulation Authority on nuclear power plant operations. Under the NRA’s standards, adopted after the Fukushima nuclear disaster in 2011, 620 gal is the maximum seismic acceleration allowed for reactors to continue running.
Marukawa said the maximum shaking recorded on the Sendai plant grounds was 12.6 gal.
“The NRA has judged there is no need to stop the Sendai plant,” she said.
The two reactors are the only ones currently operating in Japan.
The series of earthquakes that began in Kumamoto Prefecture on April 14 have spread eastward to Oita Prefecture. Kagoshima Prefecture lies at the southern end of Kyushu.
“Under the current circumstances, there is no need to stop the plant because (the shaking) is sufficiently low,” Chief Cabinet Secretary Yoshihide Suga said after the April 16 meeting.
The Japanese Communist Party on April 16 called on the government to shut down the Sendai plant as a preventive measure because the quake activity was spreading through Kyushu.
The party said major problems would arise in evacuations if a nuclear accident arose at the Sendai plant because quake damage has rendered the Shinkansen bullet train line and expressways unusable.
http://www.asahi.com/ajw/articles/AJ201604170031.html
Complex geology behind Kumamoto jolt
The earthquake that struck Kumamoto Prefecture early Saturday had a magnitude of 7.3, the same as the Great Hanshin Earthquake in 1995, in which more than 6,400 people died or remain missing.
The Saturday quake had more than 10 times the energy of the magnitude-6.5 earthquake that occurred Thursday evening, which caused strong shaking in limited areas. On Saturday, violent tremors measuring as high as upper 6 on the Japanese intensity scale of 7 were felt over a wide area.
Experts said the earthquake occurred as multiple faults moved in conjunction with each other, and warned that earthquakes will continue over a wide area.
According to the Japan Meteorological Agency, this is the first magnitude-7 class earthquake with a shallow focus since a magnitude-7 quake in the Hamadori area in Fukushima Prefecture, that is believed to have been an aftershock of the Great East Japan Earthquake in 2011. In the Kyushu region it was the first of that size and type in 11 years, since the magnitude-7 earthquake with its focus in the Genkainada sea in western Fukuoka Prefecture in 2005.
According to the agency’s analysis, Saturday’s quake was a “strike-slip” type, in which the fault involved moved horizontally due to its being pulled to the northwest and southeast. Thursday’s quake and the 1995 Hanshin earthquake involved the same “strike-slip” mechanism.
Yuji Yagi, an associate professor of geodynamics at University of Tsukuba, analyzed the seismic waves from the Saturday quake and said the fault appeared to have moved over an area about 50 kilometers long and 20 kilometers wide.
The underground destruction stretched northeast from the quake’s focus and continued for about 20 seconds.
The focus of Saturday’s quake was located on the northern side of the Futagawa fault zone, which cuts east to west across Kumamoto Prefecture and is at least about 64 kilometers long in its entirety.
The government’s Earthquake Research Committee had deemed there to be “an almost zero to 0.9 percent chance” of a magnitude-7 earthquake occurring in the northeast part of the Futagawa fault zone within 30 years.
The Hinagu fault zone lies to the south of the focus of Saturday’s quake, stretching at least about 81 kilometers. Part of the Hinagu fault zone is believed to have moved in the Thursday earthquake.
Yasuhiro Suzuki, a professor of tectonic geomorphology at Nagoya University, said part of the Futagawa fault zone moved in the Saturday morning earthquake. “It’s appropriate to think of the Hinagu and Futagawa fault zones as connected active faults. The earthquake on Saturday occurred in conjunction with the quakes that have happened from Thursday on, so it appears that part of a very large fault moved,” Suzuki said.
According to Takeshi Matsushima, an associate professor at Kyushu University of solid-state geophysics, the ground in the Kyushu region is subject to forces that pull it north-south. This creates the Beppu-Shimabara rift zone, in which the ground is subsided from Oita to Kumamoto. It contains the Hinagu and Futagawa fault zones, as well as the Beppu-Haneyama fault zone.
Seismic activity has intensified from the southwest to the northeast of the rift zone.
Regarding this fact, the Japan Meteorological Agency said at a Saturday press conference that “large earthquakes have occurred in three locations: Kumamoto, Aso and the central areas of Oita Prefecture.”
The government’s Earthquake Research Committee has decided to hold an emergency meeting on Sunday regarding the quakes. It will examine the causes of the seismic activity and prospects for the future.Speech
http://the-japan-news.com/news/article/0002881595
Seismic activity could move east, trigger quakes in active faults
Seismologists fear that the series of earthquakes rattling Kyushu could trigger temblors in other active faults in the southwestern island, which extend eastward into central Japan.
A number of active faults dot the so-called Beppu-Shimabara Rift, which traverses Kyushu island from east to west, extending to the Median Tectonic Line. This is the nation’s longest tectonic line, and it spans about 1,000 kilometers from the Kanto Plain through Gunma, Nagano, Wakayama, and Tokushima prefectures to Kyushu island in southern Japan.
Ichiro Kawasaki, professor emeritus of seismology at Kyoto University, said: “The epicenter (in the latest series of quakes that began April 14) is gradually moving eastward. When a fault moves, it tends to move other faults that run on an extended line.”
He explained that when an earthquake occurs, other faults around it are exerted to different pressure, which could trigger other quakes.
That view was echoed by Kazuro Hirahara, a Kyoto University professor of seismology and head of the Coordinating Committee for Earthquake Prediction.
“The epicenter of the earthquake in Oita Prefecture, (which occurred early on April 16) is about 100 kilometers from that of the Kumamoto quakes, and therefore it is hard to think that the quake was an aftershock,” he said, adding that there was a possibility the Beppu-Haneyama fault zone in the prefecture may have been stimulated.
“Quite frankly, there is no telling what may happen in the days ahead,” he said. “If some part in the Median Tectonic Line moves, there is a chance it could have an impact on the predicted Nankai Trough Earthquake in the long run.”
Shinji Toda, a Tohoku University professor of earthquake geology, pointed out that the seismic activity could also move southward.
http://www.asahi.com/ajw/articles/AJ201604160048.html
April 17, 2016
Posted by dunrenard |
Japan | Earthquakes, Sendai NPP |
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nuclear-news 