CASE STUDY: Japanese earthquake

What happened?

In March 2011 there was a 9 magnitude earthquake. It was caused by a build up of strain energy as the Pacific plate sub ducted under the Eurasian plate. It has a 30km deep focus and the epicentre was 129km east of Sendai. Aftershocks reached 6 on the Richter scale.

Where is Japan?

Japan is located at the meeting point of 3 tectonic plates: Eurasian, Pacific and Philippines. It is a destructive plate margin surrounded by faults. This means it is extremely prone to earthquakes.

What were the responses to this earthquake?

Japanese people had to turn to looting - damaging their pride. 91 countries offered aid, including blankets and food. Search and rescue teams were sent in to look for missing people, including a British rescue team. Many houses were destroyed and people were displaced. Many people were not insured and still had to pay mortgages after their home was destroyed. Many are still displaced, 6 years on, because the government wouldn't compensate. $213 billion was spent rebuilding Japan after the worst earthquake in history, however the Olympics came up and the government forget about the millions affected.

What were the impacts of this earthquake?

Flooding was a major problem, especially because of the tsunami. 16000 were killed, 3000 missing, 6000 injured, 130000 properties destroyed, 4000 roads damaged and 80 bridges damaged. Shipping and trade was disrupted - economic consequences. Transport was disrupted - the Tohoku Express closed for a couple of weeks and 20000 people were stranded in stations in Tokyo. Fukushima Nuclear Power Plant was damaged - energy crisis, economic disaster, dangerous.

What were the hazards of this earthquake?

Ground shaking - some areas were shifted 2.4 metres east. Ground subsidence - 400km of the coastline dropped 0.6 metres down, adding to the vulnerability of the area. Soil liquefaction - damaged more than 1000 buildings. Tsunami - reached heights of 39 metres and travelled 10km inland.

How was the tsunami caused?

The tsunami was a secondary consequence of the earthquake. When the strain energy was released, the Eurasian plate bounced upwards, displacing the water in the Pacific Ocean and causing a tsunami wave.