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CENTRAL CASE STUDYCENTRAL CASE STUDY

The Tohoku Earthquake:

Has It Shaken the World’s Trust

in Nuclear Power?

“This used to be one of the best places for a
NORTH
KOREA business. I’m amazed at how little is left.”
Sea of Japan — Takahiro Chiba, surveying the devastated
(East Sea) downtown area of Ishinomaki, Japan, where his
Fukushima
Daiichi family’s sushi restaurant was located
SOUTH
KOREA JAPAN “Fukushima should not just contain lessons
for Japan, but for all 31 countries with nuclear
power.”

— Tatsujiro Suzuki, Vice-chairman, Japan Atomic
North Pacific Energy Commission
Ocean

At 2:46 p.m. on March 11, 2011, the land along the northeast- as strong ocean surges followed the 1923 Tokyo–Yokohama
ern coast of the Japanese island of Honshu began to shake earthquake, pushing walls of debris in front of them and drown-
violently—and continued to shake for six minutes. These trem- ing victims still trapped in the wreckage from the earthquake.
ors were caused when a large section of the seafloor along The Japanese had built seawalls to protect against tsunamis,
a fault line 125 km (77 mi) offshore suddenly lurched, releas- but the Tohoku quake caused the island of Honshu to sink, lower-
ing huge amounts of energy through the crust and generating ing the height of the seawalls by up to 2 m (6.5 ft) in some locations.
an earthquake of magnitude 9.0 on the Richter scale (a scale Waves reaching up to 15 m (49 ft) in height then overwhelmed
used to measure the strength of earthquakes). Little did any- these defenses (Figure 2.1). The raging water swept up to 9.6
one know at the time that this quake would initiate a series of km (6 mi) inland, scoured buildings from their foundations, and
events that would affect not only Japan, but also the future of
nuclear power around the world.
The Tohoku earthquake, as it was later named, was not the Figure 2.1 Tsunami waves overtop a seawall following the
first major earthquake to strike Japan. The city of Kobe experi- Tohoku earthquake in 2011. The tsunami caused a greater loss
enced substantial damage from a quake in 1995 that claimed of life and property than the earthquake that generated it and led
over 5500 lives. And in 1923, an earthquake devastated the to a meltdown at the Fukushima Daiichi nuclear power plant.
cities of Tokyo and Yokohama, resulting in over 142,000 deaths.
Losses of life and property from the Tohoku quake were far
less extensive than the losses from these earlier events, thanks
to new stringent building codes that enable buildings to resist
crumbling and toppling over during earthquakes. But even when
the earth stopped shaking, the residents of northeastern Japan
knew that further danger might still await them—from a tsunami.
A tsunami (“harbor wave” in English) is a powerful surge
of seawater generated when an offshore earthquake displaces
large volumes of rocks and sediment on the ocean bottom,
suddenly pushing the overlying ocean water upward. This
upward movement of water creates waves that speed outward
from the earthquake site in all directions. These waves are
hardly noticeable at sea, but can rear up to staggering heights
when they enter the shallow waters near shore and can sweep
40 inland with great force. The fear of a tsunami was well founded,

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