Japanese Tsunami Case Study

Question 1

What kind of fault caused the Tohoku earthquake?

Answer 1

A thrust fault

Question 2

Between which plates was the fault which caused the tohoku earthquake?

Answer 2

North American and Pacific plates (the Pacific plate subducts beneath the the North American plate)

Question 3

What factor contributed to the shallow focus of the Tohoku earthquake?

Answer 3

The fact that it was a thrust fault

Question 4

What time and date did the Tohoku earthquake occur?

Answer 4

14:46 local time on the 3rd march 2011

Question 5

How far offshore of the Oshika peninsula was the epicentre?

Answer 5

20km to the east

Question 6

What was the magnitude of the Tohoku earthquake?

Answer 6

9.0

Question 7

How many foreshocks were there prior to the Tohoku earthquake?

Answer 7

7

Question 8

How strong was one of the foreshocks?

Answer 8

One was magnitude 7.2 2 days before the 9.0 earthquake

Question 9

How many after shocks were there of the Tohoku earthquake?

Answer 9

1235 many of which were over M7.0 and 800 of which were over 4.5

Question 10

Name 4 factors which made Japan vulnerable to tsunamis

Answer 10

1. Japan is highly vulnerable to earthquakes
2. Due to its mountainous terrain the majority of the Japanese population live on the coast
3. The upper 10 M of the soil is vulnerable to liquefaction
4. The Fukushima nuclear plant is located on the coast of Japan

Question 11

How good is Japan’s capacity to cope with earthquakes/tsunamis?

Answer 11

1. The Japanese meteorological agency detected p waves and issued televised warnings before S waves hit
2. The tsunami was predicted 3 minutes after the earthquake, giving people 20 minutes to get to safety
3. Japan’s life safe buildings reduced damage from the earthquake

Question 12

How good is Japan’s institutional capacity?

Answer 12

1. Army and emergency crews on site very quickly
2. People are trained yearly on 1st September on how to survive an earthquake- as a result of the 1923 Tokyo quake
3. Huge GDP per capita of $34000 as of 2011
4. 3rd biggest economy in the world
5. 40% of the coastline has a sea wall of up to 10m high
6. The JMA has 200 seismographs and 600 seismic intensity readers

Question 13

What were the social impacts of the Tohoku earthquake+tsunami?

Answer 13

1. People were evacuated in a 20km radius around the Fukushima nuclear plant
2. 18,854 dead
3. 26,992 injured
4. 3,155 missing
5. Elderly worst affected
6. 4.4 million in NE Japan without power
7. 1.5 million without water

Question 14

What were the economic impacts of the Tohoku earthquake and tsunami?

Answer 14

1. Fukushima went into meltdown
2. 130,000 buildings collapsed
3. 700,000 buildings partially damaged
4. $235 billion damage
5. Insured losses of $14.5-34.6 billion
6. Bank of Japan offered 15 trillion yen to stabilise the markets

Question 15

What were the environmental impacts of the Tohoku earthquake and tsunami?

Answer 15

1. Island of Honshu moved 2.4m east

2. Waves reached up to 40m in height

Question 16

What were the immediate responses to the 2011 Tohoku earthquake and tsunami?

Answer 16

1. 340,000 people were displaced and needed catering for
2. 20 minutes wasn’t enough warning for some to escape
3. Japanese government sent self defence forces
4. Japanese Red Cross reported $1 billion of donations

Question 17

What were the long term impacts of the Tohoku earthquake and tsunami?

Answer 17

1. Just 6 days after the quake a damaged motorway had been repaired
2. Japan had recovered incredibly 1 year on
3. Japanese government spent $50 billion on rebuilding