The 2011 Tohoku Earthquake
An Analysis of Vulnerability and Preparedness
An Analysis of Vulnerability and Preparedness
Research topic- I am researching the differences between a normal (but still very intense) earthquake(Kobe 1995) of a lower magnitude, and an extra powerful earthquake (Tohoku 2011). I want to cover how risk is different for different versions of the same disaster based on certain factors.
Major Issues- The first common thing I noticed was the distance between the epicenter of the quake and the location of maximum damage (The city center). I only took note of this because the more devastating earthquake actually occurred farther away from the city than the normal one. Second was about damage to buildings, in the Kobe earthquake only old wooden frame buildings were destroyed, but in the Tohoku earthquake everything was destroyed indiscriminately, resulting in 120000 buildings being totally demolished. The other difference with building damage was damage to specific type of building, nuclear power plants, only the Tohoku earthquake had any effect on them. The last thing I want to cover as a major theme is the difference between a raw earthquake and a tsunami earthquake, the Tohoku earthquake being the only one of the two to cause one.
Justification- As earthquakes they obviously connect to the idea of the class as they are hazards, and the reason I chose them is because I had no interest in any other hazards. I knew I wanted to do one in Japan and this topic fit perfectly.
Research Questions- What were the strongest disasters in Japan's recent history? What really makes the difference in damage between orders of magnitude in earthquakes? How is the damage different when comparing a tsunami earthquake to a normal one?
Science Struck. n.d. List of 19 Worst Natural Disasters in the History of Japan. [online] Available at: <https://sciencestruck.com/worst-natural-disasters-in-history-of-japan#:~:text=1%201783%20Tenmei%20Eruption.%20...%202%201792%20Mount,10%201611%20Sanriku%20Earthquake.%20...%20More%20items...%20> [Accessed 8 May 2021].
Short summary: This article is a simple list of 19 natural disasters that occurred in Japanese history. It gives a basic description of what happened in the disasters such as the number of casualties and specific locations for each.
What it contributed: This source was mostly used as a source of ideas for me. I knew I wanted to do something relating Japan, because otherwise I would have no interest in doing this project at all. After reading it I decided on the Tohoku earthquake as the main focus of my story map, and I would compare it with other earthquakes in recent history. In particular I decided on the 1995 Kobe earthquake. This earthquake was on January 17, 1995, and the main reason it was as damaging as it was is because its strength was completely unexpected, due to many very weak earthquakes happening in the area in recent history. The reported casualty number for the disaster was 6434, with 300000 people being left homeless in the aftermath. The Tohoku earthquake was on March 11, 2011, and the true source of most of the damage for this earthquake was its subsequent tsunami. The reported casualty number was 15889, with more than 120000 buildings being completely demolished and several hundred thousand more partially wrecked.
Caryl-Sue, n.d. Kobe Earthquake. [online] National Geographic Society. Available at: <https://www.nationalgeographic.org/thisday/jan17/kobe-earthquake/> [Accessed 24 May 2021].
Short Summary: This article gives a description of the Kobe earthquake with some very specific numbers not mentioned in the article about multiple disasters above, including the magnitude and cost of damages. It is meant as a quick info base because it is actually a "this day in history" story, rather than a disaster report.
What it contributed: The Kobe earthquake was a 6.9 one the Richter scale, and caused over $100 billion in damage. I also learned that Japan is incredibly tectonically active because it has 4 major plates that interact all around it, they plates are: The Eurasian, Philippine, Pacific, and North American. The Kobe earthquake was a result of the Eurasian and Philippine plates slipping, the epicenter of which was 15 miles from the city itself.
Unlisted. (2009, May 27). Facts About the Kobe Earthquake (Great Hanshin Earthquake). Science Struck. https://sciencestruck.com/facts-about-kobe-earthquake-great-hanshin-earthquake. [Accessed 06 June 2021]
Short Summary: This source is mostly a Did You Know facts list, however it has a ton of useful information. I figure that it was mostly created as just an information dump that would list just about anything someone may want to know about the Kobe Earthquake.
What it Contributed: The Earthquake happened at 5:46 AM, it was only 20 seconds long, and the tectonic plats moved 18 cm horizontally, and 12 cm vertically. There were actually foreshocks the night before, 4 of them in fact, and more than 50 aftershocks in the week after. Based on estimates, in the worst affected area 1 in 5 buildings was destroyed. This is because the eastern section of the city was filled with older traditional houses, they all basically turned to rubble. In fact 9 out of 10 deaths were because these traditional homes had heavy roofs that fell when the walls collapsed on landed on their residents because of the fact they were designed to defend against typhoons.
Banba, M., & Shaw, R. (2016, February 19). Postdisaster Urban Recovery: 20 Years of Recovery of Kobe. Urban Disasters and Resilience in Asia. https://www.sciencedirect.com/science/article/pii/B978012802169900015X#:~:text=The%20characteristics%20of%20the%20recovery%20of%20Kobe%20from,just%20bringing%20it%20back%20to%20what%20it%20was. [Accessed 06 June 2021]
Short Summary: This article is an overview of the ideology and process by which the city of Kobe recovered from the earthquake. It is part of a book about Urban disasters in Asia.
What it contributed: While recovering from the earthquake, the Government adopted a policy called Creative Recovery. This means that rather than returning the city to the way it was prior to the disaster, they would transform the city into one that would lead the modern world. This was accomplished via urban redevelopment projects and land readjustments. There was a lot of public involvement in this process, and thus the people of the city greatly contributed to its recovery.
Caryl-Sue, n.d. Tohoku Earthquake and Tsunami. [online] National Geographic Society. Available at: <https://www.nationalgeographic.org/thisday/mar11/tohoku-earthquake-and-tsunami/#:~:text=On%20March%2011%2C%202011%2C%20Japan%20experienced%20the%20strongest,of%20Honshu.%20The%20Tohoku%20earthquake%20caused%20a%20tsunami.> [Accessed 24 May 2021].
Short Summary: Just like the other National Geographic source source, this is a slightly more specific description of the Tohoku earthquake. Once again, it is actually a "this day in history" article, rather than a disaster report, so it only has a quick set of basic numbers that expand upon the list of numbers from the first source.
What it contributed: The Tohoku earthquake was the strongest earthquake in Japan's recorded history, at 9.0 on the Richter scale. and it was 81 miles away from Sendai City. The Tsunami caused by the Earthquake was 132 feet tall. It also caused massive damage to all kinds of structures, including 3 nuclear power stations that suffered meltdowns.
Dunbar, P., McCollough, H., Mungov, G., Varner, J. and Stroker, K., 2015. Great Tohoku, Japan Earthquake and Tsunami, 11 March 2011 | NCEI. [online] Ngdc.noaa.gov. Available at: <https://ngdc.noaa.gov/hazard/11mar2011.html> [Accessed 24 May 2021].
Short Summary: This source was the meat of my research. The link it self leads to a website with a short excerpt from a PDF paper that it links to. The paper is the real source of information, it covers most of the specific details about the Tohoku earthquake, but I was unable to cite it directly. It has lots of numbers and a short list of other comparable hazards. It includes exact coordinates and damage costs for specific regions around the world. It is effectively a comprehensive report of the earthquake and succeeding tsunami.
What it contributed: First off, the Tsunami damaged far more than just Sendai. As it radiated out from the epicenter off of the coast of Japan, it continued its path of destruction. It caused damage to Hawaii, California, and even as far away Chile down in South America. This is also the first observed occurrence of damage to Ice shelfs in Antarctica due to a Tsunami. Luckily, compared to the damage in Japan, the damage elsewhere was minimal. In Japan the Tsunami caused $220 billion in destruction, while it did $30 million in Hawaii, $55 million in California, and $6 million in Chile. Also in those other regions, damage was mostly restricted in Marine buildings and the fishing industry, rather than indiscriminate destruction.
Unlisted. (2021, March 10). On This Day: 2011 Tohoku Earthquake and Tsunami. National Centers for Environmental Information (NCEI). https://www.ncei.noaa.gov/news/day-2011-japan-earthquake-and-tsunami. [Accessed 06 June 2021]
Short Summary: This article was written under the position of "10 years later" and it covers 3 topics. The three things it mainly covers are "how it happened", "high costs", and "peril to preparedness". In other words it describes why the earthquake occurred, the damages it caused, and what the citizenry learned as a result.
What it contributed: the Tohoku earthquake was a result of a fault in the subduction zone between the North American and Pacific plates, which happen to be the two that we not involved in the Kobe earthquake that could have a bearing on Japan. The damage costs actually make this the most costly disaster in history. Despite the high casualty count in Japan, there were only 2 deaths because of the tsunami beyond it (1 in Indonesia and 1 in California+ thanks to the Pacific Tsunami Warning System. After the Tsunami, Japan made major efforts in order to study and learn how to prevent them. They took over 6000 wave measurements and updated building codes in order to stand up to Tsunamis.
Unlisted. (n.d.). The Warning System. Pacific Tsunami Museum. http://tsunami.org/the-warning-system/. [Accessed 06 June 2021]
Short Summary: This piece is a step by step explanation of how the Pacific Tsunami System Works. It is there for anyone that may want to know what keeps them safe from tsunamis and to supplement what is in the Pacific Tsunami Museum.
What it contributed: First seismographs read the earthquakes that occur on the ocean floor, Scientists always monitor the readings from these to see if an earthquake is large enough to actually start a tsunami. If they spot on that is, they will then watch the DART (Deep-ocean Assessment and Reporting of Tsunamis) Buoys to find out the size of the wave. They then use that data along with the depth of the ocean and distance from land to calculate if/when the tsunami will reach land and issue a tsunami warning to any potentially effected areas.
Unlisted. (n.d.). The Relationship between Earthquakes and Tsunamis. Actforlibraries.org. http://www.actforlibraries.org/the-relationship-between-earthquakes-and-tsunamis/.
Short summary: This source is exactly what it sounds like, a description of what the differences and similarities between earthquakes and tsunamis are. It is simply an educational article to teach said relationship.
What it contributed: First off is the fact that tsunamis are always caused by deep water displacements, and therefore cannot be caused by land based earthquakes. This is why the Kobe earthquake did not cause a tsunami, because it technically happened on islands just south of the city, not the middle of the ocean. Also, if an earthquake occurs too deep below the surface, it will not cause a tsunami because it does not displace enough water near the surface, rather it spreads out in a half sphere and does not affect the surface. Additionally, tsunamis require a solely upward slope to the seabed in order to maintain there shape, or they will simply dissipate, which is another reason tsunamis will not appear as a land based earthquake radiates out from its epicenter.
McCurry, J., 2011. Japan's Fukushima nuclear plant under state of emergency after quake. [online] the Guardian. Available at: <https://www.theguardian.com/world/2011/mar/11/japan-declares-nuclear-emergency-quake> [Accessed 24 May 2021].
Short summary: This is a news article that reported on the nuclear reactor meltdowns that occurred after the Tohoku earthquake. It gives a general story of what happened, because it was actually written around the time that everything was happening. It revealed numbers that apply to my research, and descriptions of what happened at some of the specific reactors.
What it contributed: Because of the Earthquake, the cooling system in the Fukushima nuclear reactor failed, resulting in a meltdown. Fortunately, the local Government had seen this coming and people in a 2 mile radius had been ordered to evacuate, which was around 3000 people. This was because the water levels in the cooling system were steadily falling, rather than immediately dropping to 0, which gave the workers the opportunity to try to stop or at least delay the meltdown and therefore evacuate the surrounding area.
What I learned: I learned a ton about earthquakes and the damage and different effects that they can have based on many factors I didn't consider. For example, I did not know that earthquakes had epicenters that radiate out lowering the magnitude as it gets further away. I always thought that the magnitude stayed the same for all locations within the specific location of the whole earthquake. Also I learned about the effects on nuclear power plants and how governments will respond to disasters that threaten nuclear power stations and about how tsunamis are actually caused and why they don't happen all the time.
What it has to do with the class: Everything frankly. Learning about the effects on different things from different disasters is exactly what this class is, so my research just expands and compounds on what we have already been taught about earthquakes.
Application: There is a simple lesson and that is basic earthquake preparedness. Many governments require young people to be taught about earthquakes, but I don't think it really sticks. Most don't learn about the damage that they truly cause via tsunamis or nuclear meltdowns. So I suggest that there be some form of required education that will actually get people to understand the risk. Understanding is the first key to reducing vulnerability after all, simple earthquake drills like we get in primary school are not enough.