THE GREAT EASTERN JAPAN EARTHQUAKE & TSUNAMI OF MARCH 11, 2011 (Tohoku or 3.11 Earthquake)
Its epicenter was 70km east of the mainland at a depth of 30km below the surface of the water. It was the most powerful earthquake ever in Japan and the fourth most powerful earthquake in the world since modern record keeping started in 1900.
This earthquake occurred where the Pacific Plate is subducting under the plate beneath northern Honshu. The Pacific plate, which moves at a rate of 8 to 9 cm per year, dips under Honshu’s underlying plate building large amounts of elastic energy. This motion pushes the upper plate down until the accumulated stress causes a seismic slip-rupture event. Three tsunami deposits have inundated the Sendai plain, all within the last 3,000 years, suggesting an 800 to 1,100 year recurrence interval for large tsunamigenic earthquakes. One was the estimated 8.4 magnitude 869 Sanriku earthquake. Other major earthquakes with tsunamis struck this area in 1896 and in 1933. These earthquakes with magnitudes about 7 since 1926 in this area had released only part of the accumulated energy.
In 2001 it was reckoned that there was a high likelihood of a large tsunami hitting the Sendai plain as more than 1,100 years had then elapsed. In 2007, the probability of an earthquake with a magnitude of 8.1–8.3 was estimated as 99% within the following 30 years. For several reasons, it is unusual for the magnitude of an earthquake to exceed 8.5 in this area and the magnitude of this earthquake was a surprise. The earthquake ruptured the fault zone for a length of 500 km.
The surface energy of the seismic waves from the earthquake was calculated to be at 1.9×1017 joules which is nearly double that of the 9.1 2004 Indian Ocean earthquake and tsunami that killed 230,000 people in SE Asia and Africa. If harnessed, the seismic energy from this earthquake would power a city the size of Los Angeles for an entire year. The seismic moment, which represents the physical size for the event, was calculated at 3.9×1022 joules, slightly less than the 2004 Indian Ocean quake.
A 400-kilometre stretch of coastline dropped vertically by 0.6 metres allowing the tsunami to travel farther and faster onto land. The seabed in the area between the epicenter and the Japan Trench moved 50 metres east-southeast and rose about 7 metres (23 ft) as a result of the quake. The earthquake moved Honshu (the main island of Japan) 2.4 m east, shifted the Earth on its axis by 10 cm – 25 cm, and generated infrasound waves detected in perturbations of the low-orbiting GOCE satellite. The GPS station located nearest the epicenter moved almost 4m. The Earth’s rotation was changed by the earthquake to the point where days are now 1.8 microseconds shorter.
AFTERSHOCKS. Japan has experienced over 1,000 aftershocks since the earthquake, with 80 registering over magnitude 6.0 Mw and several of which have been over magnitude 7.0 Mw
SUBSIDENCE. Large areas of the coast sunk by .29 to 1.2 metres. Scientists say that the subsidence is permanent. As a result, the communities in question are now more susceptible to flooding during high tides.
CASUALTIES
15,894 died, 6,152 were injured, and 2,562 people were never found across twenty prefectures. 14,308 or 92.5% died by drowning, 667 were crushed to death or died from internal injuries, and 145 perished from burns. Victims aged 60 or older accounted for 65.2% of the deaths, with 24% of total victims being in their 70s. Noted individual fatalities within Japan included 103-year-old Takashi Shimokawara, holder of the world athletics records in the men’s shot put, discus throw and javelin throw for the over-100s age category.
As many as 100,000 children were uprooted from their homes, some of whom were separated from their families because the earthquake occurred during the school day. 1,580 children lost either one or both parents. One elementary school in Ishinomaki, Miyagi, Okawa Elementary, lost 74 of 108 students and 10 of 13 teachers and staff.
The Japanese Foreign Ministry confirmed the deaths of nineteen foreigners: two English teachers from the United States, a Canadian missionary in Shiogama and citizens of China, North and South Korea, Taiwan, Pakistan and the Philippines.
Japanese funerals are elaborate Buddhist ceremonies that entail cremation. The thousands of bodies, however, exceeded the capacity of available crematoriums and morgues, many of them damaged, and there were shortages of both kerosene—each cremation requires 50 litres—and dry ice for preservation. The single crematorium in Higashimatsushima, for example, could only handle four bodies a day, although hundreds were found there.[ Governments and the military were forced to bury many bodies in hastily dug mass graves with rudimentary or no rites, although relatives of the deceased were promised that they would be cremated later.
The tsunami is reported to have caused several deaths outside Japan. One man was killed in Jayapura, Papua, Indonesia after being swept out to sea. A man who is said to have been attempting to photograph the oncoming tsunami at the mouth of the Klamath River, south of Crescent City, California, was swept out to sea. His body was found on 2 April along Ocean Beach in Fort Stevens State Park, Oregon, some 330 miles (530 km) to the north.
As of March 2012, 1,331 deaths were indirectly related to the earthquake, such as caused by harsh living conditions after the disaster and 18 people had died and 420 had been injured while participating in disaster recovery or clean-up efforts.
TSUNAMI
This up thrust along a 180-km-wide seabed resulted in a major tsunami that brought destruction along the Pacific coastline of Japan’s northern islands. The resulting powerful tsunami waves reached heights of up to 40.5 metres (133 ft) in Miyako in Tōhoku’s Iwate Prefecture, and which, in the Sendai area, traveled up to 10 km (6 mi) inland.
The tsunami warning was the most serious on its warning scale and the tsunami inundated a total area of approximately 561 km2.
Just over an hour after the earthquake, a tsunami was observed flooding Sendai Airport with waves sweeping away cars and planes and flooding various buildings. At least 101 designated tsunami evacuation sites were hit by the wave.
Like the 2004 Indian Ocean earthquake and tsunami, the damage by surging water, though much more localized, was far more deadly and destructive than the actual quake. Entire towns were destroyed in tsunami-hit areas in Japan.
DAMAGE.
Among several factors causing the high death toll from the tsunami, one was the unexpectedly large size of the water surge. The tsunami walls at several of the affected cities were based on much smaller tsunami heights. Also, many people caught in the tsunami thought that they were located on high enough ground to be safe.
Large parts of Kuji and the southern section of Ōfunato including the port area were almost entirely destroyed. Also largely destroyed was Rikuzentakata, where the tsunami was three stories high. Other cities destroyed or heavily damaged by the tsunami include Kamaishi, Miyako, Ōtsuchi, and Yamada (in Iwate Prefecture), Namie, Sōma and Minamisōma (in Fukushima Prefecture) and Shichigahama, Higashimatsushima, Onagawa, Natori, Ishinomaki, and Kesennuma (in Miyagi Prefecture). The most severe effects of the tsunami were felt along a 670-kilometre-long (420 mi) stretch of coastline from Erimo, Hokkaido, in the north to Ōarai, Ibaraki, in the south, with most of the destruction in that area occurring in the hour following the earthquake. Near Ōarai, people captured images of a huge whirlpool that had been generated by the tsunami. The tsunami washed away the sole bridge to Miyatojima, Miyagi, isolating the island’s 900 residents. A two-metre-high tsunami hit Chiba Prefecture about 2½ hours after the quake, causing heavy damage to cities such as Asahi. Many areas were also affected by waves of 1 to 3 metres. The timing of the earliest recorded tsunami maximum readings ranged from 26 and 35 minutes after the earthquake had struck.
The tsunami at Ryōri Bay, Ōfunato was about 30 m high. Fishing equipment was scattered on the high cliff above the bay. At Tarō, Iwate, the tsunami reached a height of 37.9 m up the slope of a mountain some 200 m from the coastline. Also, a mountain 400 m from the coast at Aneyoshi on the Omoe peninsula, Miyako, Iwate had tsunami run up height of 38.9m. This height is deemed the record in Japan exceeding the 38.2m from the 1896 Meiji-Sanriku earthquake. Only 58% of people in coastal areas in Iwate, Miyagi, and Fukushima prefectures heeded tsunami warnings immediately after the quake and headed for higher ground. Of those who attempted to evacuate after hearing the warning, only five percent were caught in the tsunami. Of those who didn’t heed the warning, 49% were hit by the water.
ELSEWHERE ACROSS the PACIFIC
A widespread tsunami warning covered the entire Pacific Ocean. In California and Oregon, up to 2.4-metre-high (tsunami surges hit some areas, damaging docks and harbours and causing over US$10 million in damage. In Curry County, Oregon $7 million in damages occurred including the destruction of 1,100m of dock. Surges of up to 1m hit Vancouver Island. In the Philippines, waves up to 0.5m high hit the eastern seaboard. Some houses along the coast in Jayapura, Indonesia were destroyed. Wewak, East Sepik, Papua New Guinea was hit by the waves, causing an estimated US$4 million in damages. Hawaii estimated damage to public infrastructure alone at US$3 million, with damage to the Four Seasons Resort Hualalai, estimated at tens of millions of dollars. It was reported that a 1.m wave completely submerged Midway Atoll‘s reef inlets and Spit Island, killing more than 110,000 nesting seabirds at the Midway Atoll National Wildlife Refuge.
Some other South Pacific countries, including Tonga and New Zealand, and U.S. territories of American Samoa and Guam, experienced larger-than-normal waves, but did not report any major damage. However, in Guam some roads were closed off and people were evacuated from low-lying areas.
Along the Pacific Coast of Mexico and South America, tsunami surges were reported, but in most places caused little or no damage. Peru reported a wave of 1.5m and more than 300 homes were damaged. The surge in Chile was large enough to damage more than 200 houses, with waves of up to 3m In the Galápagos Islands, 260 families received assistance following a 3-metre surge which arrived 20 hours after the earthquake, after the tsunami warning had been lifted. The tsunami broke icebergs off the Sulzberger Ice Shelf in Antarctica, 13,000 kilometres away. The main iceberg was 125 square kilometres, measured 9.5 by 6.5 kilometres (approximately the area of Manhattan Island) and was about 80 metres thick.
As of April 2012, wreckage from the tsunami spread around the oceans, including a soccer ball found in Alaska and a Japanese motorcycle found in British Columbia, Canada (now in the Harley Davidson museum).
DAMAGE and EFFECTS
The degree and extent of damage caused by the earthquake and resulting tsunami were enormous, with most of the damage being caused by the tsunami. Video footage of the towns that were worst affected shows little more than piles of rubble, with almost no parts of any structures left standing. Estimates of the cost of the damage range well into the tens of billions of US dollars; before-and-after satellite photographs of devastated regions show immense damage to many regions. Although Japan has invested the equivalent of billions of dollars on anti-tsunami seawalls which line at least 40% of its 34,751 km (21,593 mi) coastline and stand up to 12 m (39 ft) high, the tsunami simply washed over the top of some seawalls, collapsing some in the process.
45,700 buildings were destroyed and 144,300 were damaged by the quake and tsunami. Three hundred hospitals with 20 beds or more in Tōhoku were damaged by the disaster, with 11 being completely destroyed. The earthquake and tsunami created an estimated 24–25 million tons of rubble and debris in Japan.
An estimated 230,000 automobiles and trucks were damaged or destroyed in the disaster. As of the end of May 2011, residents of Iwate, Miyagi, and Fukushima prefectures had requested deregistration of 15,000 vehicles, writing them off as unrepairable or unsalvageable.
Ports. All of Japan’s ports were briefly shut down after the earthquake, though the ones in Tokyo and southwards soon re-opened. Fifteen ports were located in the disaster zone. The north eastern ports of Hachinohe, Sendai, Ishinomaki and Onahama were destroyed, while the Port of Chiba (which serves the hydrocarbon industry) and Japan’s ninth-largest container port at Kashima were also affected, though less severely. The ports at Hitachinaka, Hitachi, Soma, Shiogama, Kesennuma, Ofunato, Kamashi and Miyako were also damaged and closed to ships. All 15 ports reopened to limited ship traffic by 29 March 2011. A total of 319 fishing ports, about 10% of Japan’s fishing ports, were damaged in the disaster. Most were restored to operating condition by 18 April 2012.
Dams and water problems. The Fujinuma irrigation dam in Sukagawa ruptured with washing away of five homes with 8 deaths. Of 252 dams inspected, asix embankment dams had shallow cracks on their crestsd, all functioning with no problems. In the immediate aftermath of the calamity, at least 1.5 million households lost access to water supplies. By 21 March 2011, this number fell to 1.04 million.
Electricity. 4.4 million households served by Tōhoku Electric Power (TEP) in northeastern Japan were left without electricity when several nuclear and conventional power plants went offline after the earthquake. Rolling blackouts began on 14 March due to power shortages as production was reduced from 40 to 30 GW. This was because 40% of the electricity used in the greater Tokyo area was supplied by reactors in the Niigata and Fukushima prefectures. The reactors at the Fukushima Daiichi and Fukushima Dai-ni plants were automatically taken offline when the first earthquake occurred and sustained major damage related to the earthquake and subsequent tsunami. Blackouts affected Tokyo, Kanagawa, Eastern Shizuoka, Yamanashi, Chiba, Ibaraki, Saitama, Tochigi, and Gunma prefectures. By 21 March 2011, the number of households in the north without electricity fell to 242,927.
Power company often cannot share electricity, because some systems operate at 60 hertz, whereas others operate their systems at 50 hertz; this is due to early industrial and infrastructure development in the 1880s that left Japan without a unified national power grid.
Oil, gas and coal
A oil refinery of Cosmo Oil Company was set on fire by the quake to the east of Tokyo. In Sendai, a refinery owned by JX Nippon Oil & Energy, was also set ablaze by the quake. Back-up power plants burning fossil fuels tried to compensate for the loss of 11 GW of Japan’s nuclear power capacity.
The city-owned plant for importing liquefied natural gas in Sendai was severely damaged, and supplies were halted for at least a month. Several power plants were damaged.
Nuclear power plants. The Fukushima Daiichi, Fukushima Daini, Onagawa Nuclear Power Plant and Tōkai nuclear power stations, consisting of a total eleven reactors, were automatically shut down following the earthquake. Cooling is needed to remove decay heat after a Generation II reactor has been shut down, and to maintain spent fuel pools. The backup cooling process is powered by emergency diesel generators. At Fukushima Daiichi and Daini, tsunami waves overtopped seawalls and destroyed diesel backup power systems, leading to severe problems at Fukushima Daiichi, including three large explosions and radioactive leakage. Subsequent analysis found that many Japanese nuclear plants, including Fukushima Daiichi, were not adequately protected against tsunami. Over 200,000 people were evacuated.
The Onagawa Nuclear Power Plant, the closest nuclear plant to the epicenter earthquake, remained largely undamaged. The plant’s 3 reactors automatically shut down without damage and all safety systems functioned as designed. The plant’s 14-metre-high (46 ft) seawall successfully withstood the tsunami.
Fukushima Daiichi is not the worst nuclear accident ever, but it is the most complicated. Nuclear experts stated that Fukushima will go down in history as the second-worst nuclear accident ever…. while not as bad as Chernobyl disaster, worse than Three Mile Island accident. It could take months or years to learn how damaging the release of dangerous isotopes has been to human health and food supplies, and the surrounding countryside.
Later analysis indicated three reactors at Fukushima I had suffered meltdowns and continued to leak coolant water.
Radioactive iodine and cesium were detected in the tap water and soil. Food products were also found contaminated by radioactive matter in several places in Japan. In April 2011, the government of the Ibaraki banned the fishing of sand lance. As late as July 2013 slightly elevated levels of radioactivity were found in beef on sale at Tokyo markets. No death or morbidity has so far been reported as a result of the radioactive emissions.
Incidents elsewhere
Transport
Japan’s transport network suffered severe disruptions. Many sections of Tōhoku Expressway serving northern Japan did not reopen until 24 March 2011. All railway services were suspended in Tokyo, with an estimated 20,000 people stranded at major stations across the city. In the hours after the earthquake, some train services were resumed. Most Tokyo area train lines resumed full service by the next day—12 March.[ Twenty thousand stranded visitors spent the night of 11–12 March inside Tokyo Disneyland.
A tsunami wave flooded Sendai Airport 1 hour after the quake, causing severe damage. Various train services around Japan were also canceled, with JR East suspending all services for the rest of the day. in the worst-hit areas, 23 stations on 7 lines were washed away, with damage or loss of track in 680 locations.
Derailments were minimized because of an early warning system that detected the earthquake before it struck. The system automatically stopped all high-speed trains, which minimized the damage. 1,100 sections of the Tōhoku Shinkansen line needed repairs. The pre-earthquake timetable was not reinstated until late September.
The rolling blackouts brought on by the crises at the nuclear power plants in Fukushima had a profound effect on the rail networks around Tokyo with 10–20 minute intervals, rather than the usual 3–5 minute intervals, operating some lines only at rush hour and completely shutting down others.This led to near-paralysis within the capital, with long lines at train stations and many people unable to come to work or get home. Railway operators gradually increased capacity over the next few days, until running at approximately 80% capacity by 17 March and relieving the worst of the passenger congestion.
Telecommunications. Immediately after the earthquake cellular communication was jammed across much of Japan due to a surge of network activity.
Defence. Matsushima Air Field was struck by the tsunami, flooding the base and resulting in damage to all 18 Mitsubishi F-2 fighter jets. 12 of the aircraft were scrapped, while the remaining 6 were slated for repair at a cost of 80 billion yen ($1 billion), exceeding the original cost of the aircraft. 2 patrol boats of the Japan Coast Guard were swept away.
Cultural properties 754 cultural properties were damaged across nineteen prefectures, including five National Treasures (at Zuigan-ji, Ōsaki Hachiman-gū, Shiramizu Amidadō, and Seihaku-ji); 160 Important Cultural Properties (including at Sendai Tōshō-gū, the Kōdōkan, and Entsū-in, with its western decorative motifs); one hundred and forty-four Monuments of Japan (including Matsushima, Takata-matsubara,Yūbikan, and the Site of Tagajō); six Groups of Traditional Buildings; and four Important Tangible Folk Cultural Properties. Stone monuments at the UNESCO World Heritage Site: Shrines and Temples of Nikkō were toppled. In Tokyo, there was damage to Koishikawa Kōrakuen, Rikugien, Hamarikyū Onshi Teien, and the walls of Edo Castle.
AFTERMATH
Included both a humanitarian crisis and a major economic impact. The tsunami resulted in over 340,000 displaced people, shortages of food, water, shelter, medicine and fuel. Economically, industrial production was suspended in many factories. Longer term issues are rebuilding an estimated ¥10 trillion ($122 billion).
Japan’s coastal cities and towns were left with nearly 25 million tons of debris. In Ishinomaki alone, there were 17 trash collection sites 180 metres long and at least 4.5 metres high. An official in the city’s government trash disposal department estimated that it would take three years to empty these sites.
In April 2015, authorities off the coast of Oregon discovered debris that is thought to be from a boat destroyed during the tsunami. Cargo contained yellowtail jack fish, a species that lives off the coast of Japan, still alive. KGW estimates that more than 1 million tons of debris still remain in the Pacific Ocean[
Also, following the earthquake, for the first time in Japanese history, the Emperor addressed the nation in a pre-recorded television broadcast.
The Struggle to Repopulate Fukushima
The government pushes villagers back to the homes they left
From his desk, the mayor of Iitate, Norio Kanno, can see the beloved patchwork of forests, hills and rice paddies that he has governed for over two decades. A book in the lobby of his office calls it one of Japan’s most beautiful places, a centre of organic farming. The reality outside mocks that description. The fields are mostly bald, shorn of vegetation in a Herculean attempt to remove the radioactive fallout that settled six years ago. There is not a cow or farmer in sight. Tractors sit idle in the fields. The local schools are empty.
Iitate, a cluster of hamlets spread over 230 square kilometres, was hit by a quirk of the weather. After the accident at the Fukushima Dai-ichi nuclear power plant, 45km (28 miles) away, which suffered meltdowns after a tsunami in 2011, wind carried radioactive particles that fell in rain and snow on a single night. Belatedly, the government ordered the evacuation of the 6,000 villagers. Now it says it is safe to return. With great fanfare, all but the still heavily contaminated south of Iitate—the hamlet of Nagadoro—was reopened on March 31st (see map).
The only part of the village that looks busy, however, is the home for the elderly. Locals say a few hundred people, at most, have returned, predominantly the retired. Mr Kanno will not reveal how many “because it gives the impression that we are forcing people to live here, which we don’t intend to do.” Yet many evacuees now face a stark choice: return to Iitate, or lose part of the compensation that has helped sustain them elsewhere.
Last month this dilemma was expressed with unusual clarity by Masahiro Imamura, the minister in charge of reconstruction from the disaster. Pressed by a reporter, Mr Imamura said it was the evacuees’ “own responsibility, their own choice” whether or not to return. The comment touched a nerve. “It’s economic blackmail,” says Nobuyoshi Ito, a local farmer. Mr Imamura has since resigned.
Nobody wants Fukushima mentioned in the same breath as Chernobyl. Almost three decades after the world’s worst nuclear accident, life there is still frozen in time, a snapshot of the mid-1980s Soviet Union, complete with posters of Lenin on school walls. By contrast, about ¥200m ($1.8m) per household has been spent decontaminating Iitate, helping to reduce radiation in many areas to well under 20 millisievert per year (the typical limit for nuclear-industry workers). But the clean-up extends to only 20 metres around each house, and most of the village is forested mountains. In windy weather, radioactive caesium is blown back onto the fields and homes.
Nevertheless, Mr Kanno says it is time to cut monthly compensation payments which, in his view, encourage dependence. In 2012 Iitate’s became the first local authority in Fukushima prefecture to set a date for ending evacuation. The mayor pledged that year to revive the village in five years, a promise he has kept. A new sports ground, convenience store and noodle restaurant have opened. A clinic operates twice a week.
All that is missing is people. Less than 30% of Iitate’s former residents want to return. (In Nagadoro, over half said they would never go back.) Many have used earlier lump-sum payments to build lives elsewhere. Before the disaster struck, the village had already lost a third of its population since 1970 as young folk moved to the cities—a process that has hollowed out many a furusato, or home town.
Families left behind quarrel about whether to leave or stay, says Yoshitomo Shigihara, a villager. “Some try to feel out whether others are receiving benefits, what they are getting or how much they have received in compensation. It’s very stressful to talk to anyone in Iitate.” Some wanted to move the entire village to one of the country’s many depopulated areas but Mr Kanno would not hear of it. In trying to save the village, says Mr Ito, the mayor may be destroying it for good.
