EEFIT Japan earthquake report published
The Earthquake Engineering Field Investigation Team (EEFIT) has now published its report which examines the effects of the 2011 Japan earthquake.
On 11 March the north eastern coast of Japan was hit by a 9 magnitude earthquake and tsunami. The event captivated audiences worldwide as the devastating effect to Japan's infrastructure unravelled – not least the damage sustained to the Fukushima Daiichi nuclear power plant which prevented cooling of its reactors.
A mission team of nine, led by Antonios Pomonis and deputy leader Dr Keiko Saito, was dispatched on 27 May to spend five days in Japan's Tohoku region. Most days the team were split into three separate groups covering affected areas in Iwate and Miyagi prefectures.
EEFIT have now compiled their field report entitled 'The Tōhoku, Japan Earthquake and Tsunami of 11th March 2011'. The report provides recommendations based on the findings of their mission to Japan which returned on 4 June 2011.
The main findings of the report include:
Japan's 11 March earthquake is the world's costliest earthquake on record – with losses exceeding £200 billion
The magnitude 9 earthquake ruptured an area spanning 500km in length and 200km in width}
Uncertainties surrounding Japan's energy supply and the populations health are on going – stemming from the Fukushima Daiichi nuclear power plant disaster
It has been concluded that Japan's preparedness was largely successful – with the evacuation process reducing fatalities by approximately 80 – 90 percent
Many of the damaged / collapsed buildings in Sendai were reinforced concrete structures, constructed prior to 1981 when a major revision to the Japanese seismic design code was implemented
Damage on an unimaginable scale was caused to the coastal defence structures along the north-east coast of Japan – 8,500m of breakwaters collapsed
Geotechnical failures generally did not impair the integrity of buildings in non-coastal areas. However, slope failures did result in significant displacement of low-rise residential houses sited in mountainous terrains.
The mission team carried out extensive investigations in Sendai, Shirakawa and Sukagawa – surveying ground motion and tsunami damage alongside geotechnical issues. The team also met with city officials in the region, looked at disaster and recovery management plans and the overall effect of the earthquake on the energy sector.
The mission was completed with a visit to the British Embassy in Tokyo where the team discussed its initial findings and objectives with embassy personnel, and representatives from the Ministry of Defence and Tokyo University.
The Japan report is available to download from the EEFIT website page.
The EEFIT mission team presented their findings at an evening technical meeting on Thursday 14 July 2011. The video recording from the event is available from our webinars page.