At 2:46 P.M. on March 11, 2011, one
of the most powerful earthquakes in history of Japan, hit northeastern coastal
portion of the country. It was also the fifth-most powerful earthquake ever
recorded in history. An earthquake so powerful it triggered a series of large
tsunamis that destroyed many coastal areas of the country and released a
massive amount of radioactivity which sparked a nuclear accident. This
earthquake was referred to as the Great Sendai Earthquake.
The Great Sendai Earthquake, also referred to
as the Great T?hoku Earthquake, was a magnitude-9.0 earthquake occurred in
northeastern Japan, off the country’s main island, Honshu (Pletcher). The
epicenter, or the middle of the earthquake, was located 130 kilometers east of
the city of Sendai (“A). The focus happened at a depth of thirty kilometers
below the bottom of the Pacific Ocean (“A”). It was felt as far away as Russia,
Taiwan, and China (Pletcher). The natural disaster was preceded by several
foreshocks and over 1000 aftershocks that happened days and weeks after the catastrophic
event (Zaré). This included an event that happened by weeks after the main
quake that had a magnitude-7.2 event that centered roughly forty kilometers
away from epicenter. (Pletcher).
The disaster took the public by
surprise, because few scientists predicted the country would experience an
earthquake as large as that, as the original forecast was a lot smaller and in
a different area (Oskin). The tsunami
also breached the protective sea wall that sat along the Japanese coast as the
waves were far larger than the public imagined (Petely). However, a decade
before, Japanese geologist predicted the large earthquake, but the warnings
went unheeded by officials as it was predicted based on past events that
included earthquakes and tsunamis (Oskin). Although, today, Japanese scientists
are researching these past events to better predict future disasters (Oskin). Geologists are suggesting that the natural
disaster relieved stress that the tectonic plates had collected over centuries
(“In”). Because of this, scientists are predicting that the Faultline is
unlikely to create a large earthquake anytime soon (“In”).
However, geologist are calling for a
need to research further into the earth science over the issue that the
sizeable earthquake took the public by surprise and caused them to be
ill-prepared (Petely). But the investment in the area is surprisingly low; only
two research councils in the U.K. just embarked on a joint five year research
program that is estimated to receive seven million euros in funding (Petely).
With an overall population of 127
million, Japan is one of the most densely populated countries in the world (Zaré).
The earthquake-prone country is a pioneer in crisis management and has a set of
elaborate plans in the event of a disaster (Zaré).There was a warning of the
seismic disaster one-minute prior from the Japan early warning system that
monitor stringent seismic building codes to predict when an earthquake is about
to begin (Oskin). This device had never been triggered before as it was newly
installed, and issued alerts by text-messages and television (Knight). It began
sending alerts shortly after the first, less harmful shock (Knight). This
helped save many lives as this one-minute warning shut down many (possible
high-casualty) facilities, for example trains (Oskin). However, the losses were
at the result of the tsunami as it was more fatal of the two natural disasters
Within two weeks of the disaster, the Japanese
government’s official count of death surpassed 10,000; more than one and a half
times that were still listed as missing and presumed dead (Pletcher). The
numbers dramatically increased in the following days which sprung multiple
rescue operations along the Japanese coast (Pletcher).
The official count rose to approximately 28,500, but
by the end of 2011, the number reduced to 19,300 (Pletcher). More than half the
victims were age 65 years or older (Pletcher). Out of all the prefectures in
Japan that were in the effected area, Miyagi suffered the greatest of losses as
10,800 were officially pronounced dead or missing and another 4,100 were
all the human casualties were caused by the large tsunami waves along the
coast, the earthquake was responsible for a considerable amount of damage over
a wider area (Pletcher). Fires took place in many cities such as a
petrochemical plant in Sendai, a portion of the city of Kensennuma, and an oil
refinery at Ichihara (Pletcher).
Infrastructure throughout eastern T?hoku was heavily affected with roads
and rail lines damaged, water and sewage systems disrupted, and electric power
knocked out (Pletcher). A dam, near the prefectural capital, Fukushima city,
burst due to the earthquake causing the destruction of thousands of homes in
Fukushima, Ibaraki, and Chiba prefectures (Pletcher).
The tsunami also caused a considerable amount of
oceanic litter to become a considerable concern among habitants near the
Pacific Ocean. The National Oceanic and Atmospheric Agency reported that the
tsunami carried out five million tons of debris and trash out to the sea
(Oskin). Within weeks following the disaster, much of the debris from the coast
of Japan showed up along the North American west coast (Oskin).
Another result from the natural disaster
included the significant concern of the status of several nuclear power
stations in the T?hoku region (Pletcher). Three nuclear power plants shut down
their reactors at they were closest to the epicenter (Pletcher). The
aftershocks from the earthquake cut the main power and the tsunami waves
damaged the back up generators at some of the plants, most notably the
Fukushima Daiichi plant, also known as “Number One” plant, a plant situated in
the northeastern Fukushima prefecture about 100 kilometers south of Sendai
With the power gone, the cooling
systems failed and a few days after the disaster, the cores overheated which
led to partial meltdowns of the fuel rods (Pletcher). The melted material fell
and burned sizable holes in the bottom of the containment vessels in reactors
one and two, exposing nuclear materials in the cores (Pletcher). Pressurized
hydrogen gas in the outer containment buildings enclosing the reactors caused
multiple explosions to erupt (Pletcher). Fuel rods stored in reactor four were
touched off by the fire resulting from the explosions in the first three reactors
(Pletcher). The facility released significant levels of radiation in the weeks
following the earthquake; workers sought to stabilize the damaged reactors by
cooling them with seawater and boric acid (Pletcher).
Japanese officials were afraid of possible radiation
exposure, so they established a thirty kilometer no-fly zone and created an
area of twenty kilometers around the Fukushima Daiichi plant (Pletcher). There
was a spike in levels of radiation found in the local food and water supplies
that prompted officials in Japan and overseas to issue warnings about their
consumption (Pletcher). Towards the end of March 2011, seawater near the
Daiichi facility was discovered to have been contaminated with high levels of
iodine-131, cesium-134, and cesium-137, and other radioactive isotopes which
stemmed from the exposure of pumped-in seawater that workers used to cool the
fuel coils (Pletcher). The water later had leaked in water-filled trenches and
tunnels between the facility and the ocean (Pletcher).
Japanese nuclear regulators, in mid-April, elevated
the security level of the nuclear emergency at the Fukushima Daiichi from five
to seven—the highest level on the scale created by the International Atomic
Energy Agency (Pletcher). This placed the Fukushima accident in the same
category as the Chernobyl accident, which happened in the Soviet Union in
1986). Evaluation zones were thought to be uninhabitable for decades, due to
radiation levels remaining high for many weeks after the accident (Pletcher).
However, several months after the accident, government officials announced
radiation levels in five towns just beyond the twenty kilometer radius had
declined enough to allow residents to reenter their homes, but some former
residents stayed away, concerned about the amount of radiation in the soil
In December 2011, Japanese Prime Minister Noda
Yoshihiko declared the Fukushima Daiichi facility stable, but numerous leaks
followed the accident (Pletcher). Years later, a significant leak happened in
August 2013, which was severe enough to prompt Japan’s Nuclear Regulation
Authority to classify it as a level-3 nuclear incident (Pletcher).
In the first hours of the
earthquake, the Japanese Prime Minister Kan Naoto moved to set up an emergency
command center to be located in Tokoyo (Pletcher). In result, many rescue
workers and approximately 100,000 members of the Japanese Self-Defense Force
were mobilized quickly to deal with the disaster (Pletcher). Many Japanese
citizens criticized Japan’s meteorological Agency for underestimating the size
of the tsunami wave (Oskin). Japanese officials upgraded and installed a new
tsunami warning system because of the criticism (Oskin).
However, the warnings the system
issued were unheeded by citizens as people underestimated their personal risk,
assuming that the tsunami wouldn’t reach their area (Oskin). In a study done
over the Miyagi and Fukushima prefectures, officials found that only 58% of
people headed for higher ground after the earthquake (Oskin). In Kesennuma, people
retreated to a hi-rise roof top and could only watch in horror as tsunami waves
inundated their city, knocking buildings into rubble and mixing into a kind of
tsunami ‘soup’ filled with vehicles, building parts and contents (“Rare”).
The country also requested U.S.
military personnel stationed in the country to be a part of the relief efforts,
and in turn a U.S. Navy aircraft was dispatched to the area (Pletcher). Several
other countries, such as Australia, China, Indian, New Zealand, South Korea, and
U.S., helped by sending teams for search-and-rescue, while dozens of other
countries and major international relief organizations helped with financial
and material support (Pletcher). Private and other nongovernmental
organizations from all over the world established relief funds to aid in the
rescue and recovery efforts (Pletcher). Scientists, from all over the world,
also swarmed the country to study the Faultline that caused the earthquake
(Oskin). They dropped sensors in the ocean, along the Faultline to measure the
forces that caused the seismic disaster (Oskin).
Initially, the rescue work was
essentially difficult as it was hard to get personnel, supplies, and equipment
to the devastation zone, and periods of inclement weather hindered with air operations
(Pletcher). Once workers did reach the devastation zone, they dealt with the
widespread area of destruction of entire cities that were washed away or
covered by great piles of mud and debris (Pletcher). Even though many people
were rescued in the first several days of the natural disaster, much of the
relief work consisted of the recovery of bodies (Pletcher). Hundreds of bodies
were washed ashore in several areas after they had been swept out towards to
the open sea (Pletcher).
Shelters were limited in their food
and supplies as several hundred-thousand people swept into them, while tens and
thousands more remained isolated in worse conditions, waiting for relief
efforts to reach them (Pletcher). These numbers only grew with the Fukushima
Two weeks after the earthquake, a
quarter million survivors were housed in relief shelters (Pletcher). Over two
years later, a small number remains housed in shelters as the effects of the
land were devastating (Pletcher). More than 300,000 residents were displaced
and lived in temporary homes, such as hotels, public housing units, or private
homes (Pletcher). Four years later, 230,000 people were still displaced,
however a large number was due to the continuation of the Fukushima accident (Pletcher).
The country worked to repair the
infrastructure of public services and wouldn’t stop until they were fully
operational again (Pletcher). The region’s power supply continued to be
affected with the ongoing nuclear accident in Fukushima, which caused many
temporary power outages and rolling blackouts (Pletcher).
The economy also took a hit in the
months following the disaster as it caused a severe reduction in the region’s
manufacturing output (Pletcher). The earthquake and tsunami combined caused
damage and loss of business and factories, but by late summer, the economy
repaired itself and grew briskly (Pletcher). In early 2012, industrial output
reached the level it was before the disaster (Pletcher).
The government sought to push
supplement budgets through the legislature, managing to push three different
ones through (Pletcher). In early November, the largest budget, the third one,
was approved and provided roughly $155 billion (Pletcher). A bulk of the money
raised for relief efforts went towards the reconstruction of the devastated
In February 2012, the government
also established a cabinet-level reconstruction agency to help coordinate
efforts in the coastal area (Pletcher). The government planned for the agency
to last the projected estimate it would take the Japanese northeastern coast to
be repaired; the estimate was roughly ten years (Pletcher). The agency worked
to attempt to determine if the buildings they rebuild could be made to
withstand earthquakes and tsunamis (Oskin). In late 2015, the agency reported
that the disaster was almost cleaned up as nearly all the debris from each
devastated area has been removed (Pletcher).
earthquake, an international group of scientists drilled miles beneath the Pacific
Ocean into the Faultline that caused the quake to report on why it created such
a powerful earthquake (Zielinski). Scientist believed that due odd centering of
the epicenter and the Eurasian
being lifted above the Pacific plate, that the plate wouldn’t have enough
energy to create a quake larger than a magnitude-7.5 (Zielinski). However, they
was caused by a rupture of the subduction zone, where plates slide beneath each
other into the hotter layer beneath the crust (Oskin). This certain subduction
zone was associated with the Japanese Trench, the result from the Pacific Ocean
plate pressing down under the continental plate that carries the islands of
Japan and separates the Eurasian plate from the Pacific plate (Tate). These
plates collided and released the energy that build up over centuries of
collecting energy from sticking to other plates (Oskin). Robert Harris, a study
co-author and geophysicist at Oregon State University, said in a statement to
explain the friction between the plates, “One way to look at the friction of
these big blocks is to compare them to cross-country skis on snow. At rest, the
skis stick to the snow and it takes a certain amount of force to make them
slide. Once you do, the ski’s movement generates heat and it takes much less
force to continue the movement…The same thing happens with an earthquake.”
The Chikyu team, the team of scientist that worked on
finding more knowledge on the earthquake, drilled 850 meters into the Faultline
along the seafloor of the Pacific Ocean (Zielinski). They dealt with many
obstacles such as bad weather and the actively-shifting fault that put the
instruments of study at risk (Zielinski). This revealed residual heat that
allowed the scientists calculated a low friction (Zielinski).
Emily Brodsky, a study co-author and geophysicist at
the University of California, Santa Cruz, said in a statement to the
Smithsonian, “The T?hoku fault is more slippery than anyone expected.”
(Zielinski). This explains some of the characteristics, because the fault
slipped an unprecedented fifty meters and the rupture reached the surface and displaced
the water that sat above it, which created a series of highly destructive
tsunami waves that measured approximately over thirty feet tall and reached as
far as ten kilometers inland (Zielinski). Sendai wasn’t the only city affected
by the tsunami waves; other communities, including Kamaisha and Miyako in
Iwate; Ishinomaki, Kensennuma, and Shiogama in Miyagi; and Hitachinaka and
Kitaibaraki in Ibaraki were also devastated (Pletcher).
Tsunami warnings were triggered by
the main quake throughout the Pacific basin (Pletcher). The natural oceanic
disaster raced from the epicenter towards the land at about 800 kilometers per
hour, generating waves that affected many other areas of the world, including
the Hawaiian Islands chain, Aleutian Islands chain, and the west coast of North
America (Pletcher). Eighteen hours after, waves also reached Antarctica and
caused the outer-shell of the Sulzberger Shelf to break (Pletcher).
Relief efforts and money has been
made over the course of several years to help with the reconstruction agency
and efforts of the Japanese government. But despite the havoc is wrecked, the
Sendai Earthquake was a subject of intense study as many scientific
advancements happened in wake of the disaster (“The”). New Technology left an
enormous amount of visual evidence for study in years to come, and can perhaps
help us better understand the power of earthquakes and tsunamis and prevent
loss of life in the future (“Rare”).
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