Great Tōhoku, Japan Earthquake and Tsunami, 2011

Aftermath of the Great Tōhoku, Japan earthquake
and tsunami in Otsuchi, Iwate Prefecture. Source. 

    On March 11th, 2011 at 2:46pm, a magnitude 9.0 earthquake occurred off the coast of the largest island of Japan, Honshū, generating a devastating tsunami that heavily damaged the Tōhoku region (NGDC 2015; World Nuclear Association 2020). The earthquake was the fourth largest earthquake globally since the advent of industrial recordings, shifting the earth 25cm off it's axis (NGDC 2015; Hurst 2019). The resulting tsunami was the deadliest in Japan since the 1993 Hokkaido earthquake’s resulting tsunami (NGDC 2015). The Great Tōhoku earthquake and tsunami caused 15,890 deaths, 2,590 missing and presumed dead, and 6,152 injuries in 12 different prefectures (NGDC  2015). Damages amounted to $220 billion in Japan, $30 million in Hawaii, $55 million in California, and $6 million in Chile (NGDC 2015). The 2011 earthquake and tsunami caused a nuclear disaster at the Fukushima Daiichi Nuclear Power Station after tsunami waves cut the power and cooling systems to three of the plant’s reactors (World Nuclear Association 2020). The three reactors melted down and released highly radioactive fallout over the course of six days, and over 100,000 people were evacuated from the area surrounding the power station (World Nuclear Association 2020). Radioactive Cs-134 released by the disaster was found in topsoils around the plant and 600km offshore from the power station (Dong 2016). Cs-134 deposition has severely impaired food production in the Fukushima prefecture, Cs-134 isotopes were detected in both zooplankton and midwater fish offshore of Japan (Dong 2016).

Map showing the shaking intensity experienced in different areas
of Japan during the 2011 earthquake. Source.

     Prior to the Great Tōhoku earthquake and tsunami, Japan was already well prepared for earthquakes and tsunamis (Greer 2012; Hurst 2019). Skyscrapers and other buildings are constructed so they can safely sway with an earthquake, and many cities have networks of loud speakers designed to warn citizens of an incoming tsunami (Hurst 2019). Local governments on the village, community, and city level are charged with developing disaster plans to best fit the local area and are often the first to deploy first responders and recovery efforts after a disaster (Greer 2012). At the time of the 2011 disaster, Japan also had concrete seawalls lining roughly 40% of its coastlines (Onishi 2011). The extent of the 2011 disaster demonstrated just how much Japan relies on seawalls, as they were the primary defense against tsunamis at the Fukushima Daiichi Nuclear Power Station. In order to better prepare for another earthquake and tsunami of the magnitude experienced in 2011, Japan has built an additional 245 miles of 41 foot tall seawalls (Jacobs 2018). The Japanese government also distributed a comic strip called “Tokyo ‘X’ Day” to 7 million households, depicting an average citizen navigating a disaster like that of the Great Tōhoku earthquake and tsunami in order to better educate citizens on how to react during and after a major disaster (Hurst 2019).

Map showing the predicted tsunami wave heights and travel time
following the 2011 earthquake. Source.

This video shows the March 11th tsunami washing ashore in Iwaki City, Fukushima prefecture. Water is shown quickly rising in the sewers before the main wave makes its way inland, and many vehicles and a building is washed farther inland.

Works Cited

 Dong, C. (2016). The Environmental Impact of the Fukushima Nuclear Power Plant Disaster. Retrieved from http://large.stanford.edu/courses/2016/ph241/dong1/

Greer, A. (2012). Earthquake Preparedness and Response: Comparison of the United States and Japan. Retrieved from https://ascelibrary.org/doi/pdf/10.1061/%28ASCE%29LM.1943-5630.0000179

Hurst, D. (2019). They call it X Day – a major earthquake striking the heart of the world’s most populous city in the most calamitous event since the second world war. Can hi-tech solutions save Tokyo? Retrieved from https://www.theguardian.com/cities/2019/jun/12/this-is-not-a-what-if-story-tokyo-braces-for-the-earthquake-of-a-century

Jacobs, S. (2018). 'It feels like we're in jail': Japan spent $12 billion on seawalls after the devastating 2011 tsunami — and now locals are feeling like prisoners. Retrieved from https://www.businessinsider.com/japan-seawalls-cost-12-billion-since-fukushima-disaster-2018-3

National Geophysical Data Center & National Oceanic and Atmospheric Association. (2015). MARCH 11, 2011 JAPAN EARTHQUAKE AND TSUNAMI. Retrieved from https://www.ngdc.noaa.gov/hazard/data/publications/2011_0311.pdf

Onishi, N. (2011). Seawalls Offered Little Protection Against Tsunamis Crushing Waves. Retrieved from https://www.nytimes.com/2011/03/14/world/asia/14seawalls.html

World Nuclear Association (2020). Fukushima Daiichi Accident. Retrieved from https://www.world-nuclear.org/information-library/safety-and-security/safety-of-plants/fukushima-daiichi-accident.aspx