At 2:46 P.M. on March 11, 2011, one
of the most powerful earthquakes ever recorded in history hit northeastern
Japan. An earthquake so powerful that it triggered a series of large tsunamis
that destroyed many coastal areas of the country and instigated a major nuclear
accident a power station along the coast. This earthquake has come to be known
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, and the focus occurred at a depth of thirty kilometers below the floor
of the Pacific Ocean (Pletcher). It was felt as far away as Russia, Taiwan, and
China (Pletcher). The natural disaster was preceded by several foreshocks,
including a magnitude-7.2 event that centered roughly forty kilometers away
from epicenter, and followed by multiple aftershocks in the weeks after that
were measured magnitude-6.0 (Pletcher).
was caused by a rupture of the subduction zone associated with the Japanese
Trench, which separates the Eurasian plate from the Pacific plate which
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 (Pletcher). 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).
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 number were still listed as missing and presumed dead
(Pletcher). The numbers in both categories, missing or dead, dramatically
increased in the following days which sprung multiple rescue operations along
the Japanese coast (Pletcher).
The official count for those who are confirmed dead or
still missing rose to approximately 28,500, but by the end of 2011, the number
reduced to 19,300 as more and more people were found to be alive (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 injured (Pletcher).
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
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 (Pletcher).
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 radioactive
iodine-131 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
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 (Pletcher).
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). 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
search-and-rescue teams, while dozens of other countries and major
international relief organizations, such as Red Cross and Red Crescent, 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).
Pletcher, Kenneth, and John P.
Rafferty. “Japan earthquake and tsunami of 2011.” Encyclopœdia Britannica, Encyclopœdia Britannica, inc. 22 Nov.