The Tōhoku Earthquake: Friday, 11 March 2011
On Friday, 11 March 2011 there was a powerful earthquake off the coast of Japan. It was centred off the east coast of Japan in north east Honshu (the main island of Japan) in the Tōhoku region. The epicentre was around 40 miles (60km) off the coast and as a result there was a large tsunami, or tidal wave, that hit the land devastating much of the coastline and adjacent low-lying areas. This was classed as a mega-tsunami. The earthquake measured 9 on the Richter scale or the moment magnitude scale (MMS). The MMS is a more up-to-date way of recording the quantity of energy released from an earthquake. This was the fourth most powerful earthquake to have been recorded globally (source Crowley & Elliot, 2012 ). It was the largest ever recorded by seismic instruments in Japan. The earthquake was generated by a slip on the subducting Pacific plate that goes under the plate where northern Honshu is. Japan has a complex area of plate tectonic boundaries. Several large aftershocks continues for a week after the event mainly along the Japan Trench (source: Reference ).
The Moment The Wave Hit
Fires caused by the initial earthquake rupturing gas pipelines and oil refineries led to burning debris being carried inland as homes, wood, cars and anything in the path of the wave were taken by the force of the water. A train was washed away along with small aeroplanes in Sendai airport. Electricity generation was disrupted and there were several power stations that were severely damaged which had the effect of causing widespread blackouts. Boats and large vessels where washed up as illustrated below.
In addition to the vessels washed up a huge amount of debris was also washed up. This was mainly from destroyed houses and consisted of wood and many other objects from people’s homes. It also included cars, roofs and other structures that were carried by the wave.
This oil refinery was burning just after the event. Although this is not at Ishinomaki, it shows the power of the earthquake and the devastation very graphically. Fires can often cause much damage immediately after an earthquake.
Immediate consequences were widespread in this part of Japan: The Fukushima Daiichi Nuclear Power Plant was largely destroyed and went into meltdown. There was a 20 kilometre exclusion area imposed around the power station. This lead to people having to abandon their homes and lives. Many people left and headed to the south of Japan. A few days after the tsunami there is a satellite view of Ishinomaki taken by NASA. It shows the extent of the damage. It is a false image view with blue being water, tan being exposed earth and red being vegetation. The area that I visited is on the extreme right of the image.
Copyright © Some rights reserved by NASA’s Earth Observatory Ishinomaki area damage
100,000 Japanese troops were mobilised to help to clear the wreckage. The Japanese Government, unusually, asked for international help; this was to supplement and not interfere with the well organised local agencies and government efforts.
The scene the day after the earthquake and tsunami in Ishinomaki highlights the scale of the disaster. Fires still burning on the plain which is still covered by water.
Copyright © Some rights reserved by raizo Ishinomaki the day after
Across the Pacific area the tsunami had a knock on effect. Its impact was felt as far away as Chile as well as along the west coast of the USA. This photograph illustrates the tsunami coming to shore in California. There were three big wave surges here around 1.2-1.5 metres (4-5 feet) high.
Copyright © Some rights reserved by Mike Baird Tsunami at Morro Bay, CA, USA
The following NOAA image shows the global extent of the tsunami and the area of it’s reach. The land is shown in blue and the maximum wave height in red. It is quite difficult to differentiate the different shades of red and thus wave heights.
Source: NOAA from Wikipedia
Energy Policy Shifts
The Japanese government has stated that it’s energy policy will move away from nuclear power. There is a more recent renewable energy bill that was debated after the tsunami. Solar power is becoming more popular in the country. See this Open Democracy article for a summary.
This change is also making other consider their nuclear industry: Germany has decided to phase out nuclear energy by 2022 partially as a result of the tsunami and crisis at Fukushima Daiichi. See this BBC article for further information.
18 Months Later
The clean up operation still continues. The work to clear debris is ongoing and there is a huge task to clear debris, rebuild infrastructure and rebuild lives. Many industries were destroyed along with homes and infrastructure. The disaster is thought to be the most expensive in history and has been estimated to cost around $300 billion (Crowley & Elliot, 2012).
After learning about the earthquake and other disasters at the 2012 OpenStreetMap conference in Tokyo,
I visited Ishinomaki in the north east and viewed the damage 18 months after the event. Here are my impressions of what I saw. Firstly in the centre of the city there are many gaps on the main streets where once buildings stood. These have been mainly cleared away to leave levelled plots. As the river is approached everything seems normal, but a lot quieter than should be, but upon closer inspection the buildings are empty and there is a layer of mud inside them. There is a bridge over the river that is in a poor state – it undulates but is still in use with a weight restriction.
Crossing the bridge there is more obvious damage. Many buildings have been cleared and foundations remain.
There are many destroyed or partially destroyed buildings and industrial buildings here as illustrated by this remains of a front wall complete with letterbox.
The view from the bridge nearer to the shore. The ground sank by around 1.5 metres and has also had lateral movement of around 4-5 metres out towards the sea. This illustrates boats still abandoned, partially destroyed and damaged buildings and the make-shift waste mountain. The tsunami came from the sea behind the photographer.
The last 18 months have seen the growth of weeds over the land. There are several areas where ruined cars have been collected. This image shows the ruins of the high school with the foreground once an area of houses. The debris remains in the now dead tree.
There has also been significant debris that has been washed into the Pacific Ocean. This has been modelled by the International Pacific Research Centre. They have recorded debris heading eastwards. It has recently been found that many items from this part of Japan have been washing up on the west coast of North America. Debris washing up in Oregon included a 20 metre floating dock. There have been other items washed up such as footballs and more unusual items such as a ship without crew in Sitka, Alaska (ref. BBC web site ). The have described the debris as “a unique and unrepeatable experiment in oceanography” and have mapped the progress of man-made flotsam (see reference ).
At the OpenStreetMap conference, held in Tokyo, there were several reports about humanitarian mapping projects in response to this natural disaster and others in New Zealand. What they reminded me is not only of the consequences of the earthquake on the landscape and on peoples lives but also on the psychology of the population. Earthquakes, aftershocks and their consequences have a huge impact even if people have not lost their all of their possessions or family members. They create nervousness that will take time to heal. That unease is made worse with the threat of radiation.
Things are changing, slowly, back to normality but it will be a long time before everything is back to normal. Some things will have changed for ever: families with literally nothing left, with lost family members or friends. Energy policy, in Japan and elsewhere, has been questioned and there is a resultant mover to solar power and renewable energy sources. There will be re-building, re-openings and more festivals to remember and hopefully a more resilient future to look forward to. Social coherence has very much helped in the Japanese resilience to this particular disaster. The disaster has had physical and political repercussions around the world making it truly international.
 Earthquake disasters and resilience in the global North: lessons from New Zealand and Japan, K Crowley and J R Elliot, The Geographical Journal, Vol 178, No 3 September 2012 pp208-215.
 Comet+, Centre for the Observation and Modelling of Earthquakes and Tectonics http://comet.nerc.ac.uk/current_research_japan.html
 Wikipedia article http://en.wikipedia.org/wiki/Japan_tsunami
 BBC: The tsunami debris washed from Japan to Oregon http://www.bbc.co.uk/news/magazine-19812373
 International Pacific Research Centre http://iprc.soest.hawaii.edu/news/marine_and_tsunami_debris/debris_news.php