2. On March 11, 2011, a magnitude-9 earthquake shook
northeastern Japan, unleashing a savage tsunami.
3. Cause:
Earthquake struck offshore of Japan, along a subduction zone where two of Earth's
tectonic plates collide. In a subduction zone, one plate slides beneath another into
the mantle building up energy that is released as earthquakes. East of Japan, the
Pacific plate dives beneath the overriding Eurasian plate.
Scientists drilled into the subduction zone soon after the earthquake and discovered
a thin, slippery clay layer lining the fault. The researchers think that this clay layer
allowed the two plates to slide an incredible distance, some 164 feet (50 meters),
facilitating the enormous earthquake and tsunami.
4. Before:
Residents of Tokyo received a minute of
warning before the strong shaking hit the city,
thanks to Japan's earthquake early warning
system. The country's stringent seismic
building codes and early warning system
prevented many deaths from the earthquake,
by stopping high-speed trains and factory
assembly lines. People in Japan also received
texted alerts of the earthquake and tsunami
warnings on their cellphones.
6. After:The number of confirmed deaths is 15,891 as
of April 10, 2015, according to Japan’s
National Police Agency. Most people died by
drowning. More than 2,500 people are still
reported missing.
9. After
Less than an hour after the earthquake, the first of
many tsunami waves hit Japan's coastline. The
tsunami waves reached run-up heights (how far the
wave surges inland above sea level) of up to 128 feet
(39 meters) at Miyako city and traveled inland as far
as 6 miles (10 km) in Sendai. The tsunami flooded an
estimated area of approximately 217 square miles
(561 square kilometers) in Japan.
The waves overtopped and destroyed protective
tsunami seawalls at several locations. The massive
surge destroyed three-story buildings where people
had gathered for safety. Near Oarai, the tsunami
generated a huge whirlpool offshore, captured on
video.
10. After
Nuclear meltdown
The tsunami caused a cooling system failure at
the Fukushima Daiichi Nuclear Power Plant,
which resulted in a level-7 nuclear meltdown and
release of radioactive materials. The electrical
power and backup generators were overwhelmed
by the tsunami, and the plant lost its cooling
capabilities. In July 2013, TEPCO, the Tokyo
Electric Power Company, admitted that about 300
tons of radioactive water continues to leak from
the plant every day into the Pacific Ocean.
12. Recovery
The government promised a massive response to the
catastrophic damage. Nearly 400,000 buildings as far as 2
miles inland were damaged or destroyed. The nuclear power
plant in Fukushima, about 150 miles northeast of Tokyo,
suffered a partial meltdown. And 470,000 people were forced
to find temporary homes, about half from the region
surrounding the crippled nuclear plant.
Much has been accomplished since then. About 53 million
tons of debris was hauled off to massive landfills and
incinerators. New roads and rebuilt bridges dot the coastal
area. Permanent housing has been found for nearly half of
the evacuees, and residents have been allowed to return to
some of the areas surrounding the Fukushima plant.
13. Recovery
Recovery plans include raising the level of the
town center by 8 feet in a spot where only the
shell of the two-story concrete town hall
remains standing. That will match the height of
an adjacent highway and other higher ground.
A new seawall nearly 50 feet high will be built,
as well.
14. Effects:
The tsunami waves also traveled across the Pacific,
reaching Alaska, Hawaii and Chile. In Chile, some
11,000 miles (17,000 km) distant, the tsunami was 6.6
feet (2 meters) high when they reached the shore,
according to the Pacific Tsunami Warning Center.
The surge of water carried an estimated five million tons
of debris out to sea, the National Oceanic and
Atmospheric Agency has reported. Japanese docks and
ships, and countless household items, have arrived on
U.S. and Canadian shores in the ensuing years. The
U.S. Coast Guard fired on and sank the derelict boat
164-foot Ryou-Un Maru in 2012 in the Gulf of Alaska.
15. Effects
The earthquake shifted Earth on its axis of
rotation by redistributing mass, like putting a
dent in a spinning top. The temblor also
shortened the length of a day by about
The jolt moved Japan's main island of Honshu
eastward by 8 feet (2.4 meters). The Pacific
Plate slid westward near the epicenter by 79
feet (24 m). a microsecond.
16. Effects
The tsunami broke icebergs off the Sulzberger
Ice Shelf in Antarctica.
The earthquake produced a low-frequency
rumble called infrasound, which traveled into
space and was detected by the Goce satellite.
Buildings destroyed by the tsunami released
thousands of tons of ozone-destroying
chemicals and greenhouse gases into the air.
17. Effects
Radioactive water was recently discovered
leaking from the Fukushima Daiichi Nuclear
Power Plant, which suffered a level 7 nuclear
meltdown after the tsunami. Japan relies on
nuclear power, and many of the country's
nuclear reactors remain closed because of
stricter seismic safety standards since the
earthquake. Four years after the quake, about
230,000 people who lost their homes were still
living in temporary housing
