Sample Geology Research Paper on Tohoku Earthquake

Abstract

In March 11, 2011, a huge earthquake approximated to be 9.0 (Mw) momentum magnitudes took place at the pacific offshore of Tohoku, which was the biggest earthquake on record to have ever hit Japan and its environs. The earthquake caused a huge Tsunami that struck all of the east coast along Tohoku. This caused a huge loss of people and property. The scope of this disaster’s intensity was felt at Fukushima Daiichi Nuclear Plant accident. Close to 120, 000 houses and buildings were destroyed and approximately 240,000 more collapsed. The tsunami caused by the earthquake was responsible for the massive damages and losses. This paper discusses aspects of what happened before, during, and after the occurrence of the Tohoku earthquake and tsunami.

 

Tohoku Earthquake

Introduction

The 9.0 momentum magnitude earthquake hit the off pacific coast of Tohoku in March 11, 2011 at 1446Hrs (Japan time), which was the largest to have ever occurred in the history of Japan. Initially, the earthquake was called the “2011 off the pacific coast of Tohoku earthquake” but later changed to “the 2011Tohoku Earthquake”. The powerful motions and tsunamis, which were as a result of the earthquake, were responsible for the massive damage and destructions experienced in regions around Tohoku to Kanto. According the experts, the earthquake created strong motions; a maximum of seismic intensity of 7 was witnessed at Hurihara city in Mayagi Prefecture that is near a hypocenter. In addition, an approximately upper 6 intensity was also recorded in the regions of Miyagi, Ibaraki, and Tochigi. In Miyako city, the tsunami run up heights of about 40m were recorded along the Shanriku coast along with 10 meters reaching waves experienced at a stretch of about 5000km stretch along the coast from Chiba to Aomori Prefectures. Close to 19,000 lives were lost in the catastrophe and thousands of houses and peppery destroyed with a high population of local citizens displaced from their homes. The economic quantitative impact of the disaster was approximated to be about 16.9 trillion yen. Most of the casualties in this disaster died through drowning caused by the tsunami.

Outline of the Occurrence

According to the Japanese Meteorological Agency, the hypocenter of the earthquake was at latitude 38 degrees 6’12”N, longitude 142 degrees 52’36”E, 130 kilometers east –southeast of Oshika, Peninsula, at a depth of 24km. The earthquake produced several aspects, for instance, seismic waves, crustal warp, and tsunami waveforms. The rapture that occurred during the earthquake spanned approximately in an area of about 500 kilometers length and 200 kilometers width in 180 seconds. This occurred at the boarder of North American Plate and Pacific Plate along the Japan Trench off the coast of Tohoku. Normally, there is an annual accumulation rate of 8 cm strain when the Pacific Plate sinks below the North American Plate. However, at the time of the earthquake, cumulative strain of about tens meters was released at once by the earthquake.

The jumbo earthquake is considered the greatest in the history of Japan because of its magnitude of more than 8 in the scientific seismological categorization (USGS, 2011)). The jumbo earthquake caused many damages. There were over 1000 aftershocks that were felt in the entire area, and some were stronger than previous disasters, which had been felt in the neighboring nations, such as Iran and Bam in 2003. Although the Japanese area is known for many critical earthquakes, the Tohoku earthquake was considered the heaviest to have been ever felt. Before that, there were two previous earth-shattering disasters in the history of Japan: The great Kanto earthquake, which had a magnitude of 7.9 in September 1923. The catastrophe effects were felt in Tokyo and Yokohama where consequent fires resulted in more than 143, 000 deaths and other destructions (Kurahashi & Irikura, 2013). The Kobe earthquake, also referred to as Hanshin-Awaji with a magnitude of 6.9, occurred in January 17, 1995, which left more than 6400 casualties (Midorikawa, Miura & Si, 2012). The three calamities are considered the deadliest in the history of Japan.

Tsunami that Caused Catastrophic Disasters

The Tohoku earthquake was unexpected as compared to the previous earthquakes. Data on the heights of the tsunami was recorded and published by the Tohoku Earthquake Tsunami Joint Survey Group (TTJS 2011)). The tsunami heights were approximately up to a height of about 40 m in the coastal lines of Miyako City and Sanriku. Furthermore, the tsunami waves were also felt at more than 20m height along the coastal stretch of 500km from Chiba to Aomori Prefectures. Other effects of the tsunami were floods in Sendai Plain in Miyagi Prefecture, which is a 5 km inland penetration from the coast.

A warning of the tsunami was first broadcasted at around 1449hrs by the Japanese Metrological Agency; three minutes after the earthquake had taken place. The Agency predicted that about 6 m tsunami waves would occur in Miyangi Prefecture, 3m in Iwate and Fukushima Prefectures and 1m to be felt in the pacific coast of Aomori Prefecture. The broadcast about the impending tsunami was transmitted through the radio, television, and local authorities through a dedicated line raising an alarm to the residents. A good number of people who felt the strong shaking of the earthquake and the warnings vacated to higher grounds. However, the prediction of 3 m waves caused some people to move to low elevation evacuation sites while others failed to do so because they believed in breaking waters. This led to many causalities when the real tsunami hit the area. The misleading report and warning from the Metrological agency was blamed for the casualties that led to evacuation cancellation by some victims. At 1514hs, Japanese time the same day, which was minutes later after the occurrence of the earthquake, the Agency revised its prediction broadcast and estimated 10, 6 and 3 meters tsunami heights for Miyagi, Iwate and Fukushima, and Aomori Prefectures respectively. This data was based on the GPS waves recording located on the seabed. At exactly 14 minute later, that is 1530hrs, it was predicted that the tsunami waves along the Pacific coast from Iwate Prefecture to Boso Peninsula would be at least 10 m high. However, the initial tsunami warning was received before the tsunami reached the land on the Sanriku coast. The strong motions from the earthquakes had case power outages covering a large land area and many people were already evacuating the regions. Therefore, the updated broadcast information did not reach many inhabitants who stayed along the coast (Imamura & Anawat, 2012), which led to any casualties.

The Fukushima Daiichi plant was destroyed and lost all its power as a result of strong ground motions and the tsunami waves, which were around 15m in height. This implied that the plant could not cool its reactors leading to a damaging accident entailing a core meltdown, hydrogen explosions, and release of radioactive materials. The main equipment for this plant was located at a height of 10 meters high to keep it safe from tsunamis. It was assumed that tsunamis waves would be 6. 1 meters based on the assessment by the “Tsunami Assessment Method for Nuclear Power Plants in Japan. Despite numerous tsunamis having hit the area in the past, the fact that there could be a possibility of higher tsunami with a higher intensity to be prepared for was a question that everyone asked concerning the preparedness (Satake et al., 2013).

Tohoku Earth Quake Strong Ground Motions

The strong motions, which resulted from the Tohoku earthquake, were spread to Kanto and Tohoku regions. There were estimated more than 1000 strong motion stations across the entire nation; the peak ground velocity (PGV) and the peak ground acceleration (PGA) of the earthquake weakens depending on the distance covered. The earthquake’s momentum magnitude was 9.0 in relation to the distance curves attenuation, an aspect that indicates how strong the effects were.

Japan Response to the Disaster

Overall, Japan has an estimated population of 127 million people, thereby making it one of the most densely populated nations in the world. The country covers around 340 persons per kilometer despite the fact that its population is highly concentrated around Tokyo (OECD, 2006)). Because the country is prone to earthquakes and other calamities, it is a pioneer of crisis management with comprehensive approaches for handling calamities. For instance, the established Central Council for Accident Prevention body chaired by the prime Minister is involved in setting plans for disaster responses and education. The main purpose of this organization is to ensure that in case of a calamity, people, government officials, and rescue bodies, are in good position to control and handle the situation without much anxiety.

In the management of the Tohoku earthquake in March 2011, the most effective component witnessed by emergency services was the effective behavior of people who were able to follow the commands that were issued to them. This showed that people respected their position and the cooperation was effective.

Immediately after the event, the government of Japan under the leadership of the Prime Minister, held and National Committee for Emergency Management, which declared an emergency in all the affected areas, thereby dispatching the Defense Forces for rescue operations (OCHA Japan, 2011). Each department of the government was involved, including all ministries, and local disaster response offices to aid the rescue operations in the affected regions. The ministry of health, for instance, was tasked with transportation of clean water and assigning health facilities for casualties and other people exposed to the radiations. The ministry of Agriculture, Forestry Fisheries, and Finance, on the other hand, provided food, portable toilets, blankets, and all other essential needs to the victims. Through the command from the government, all the major roads and highways in the northern part of the country were closed in order to be accessed by the emergency response activities. Furthermore, other transportation network, for instance, the subway shipping and Shinkansen train suspended their normal activities in support of the earthquake victims and rescue missions.

Additionally, the government of Japan also declared a state of nuclear emergency in the day of the occurrence because of the dangers posed by the reactors in the two Fukushima nuclear plants (I and II). This was followed by an evacuation operation of more than140, 000 residents within a distance of 20 kilometers for the plant. On 12 March, at around 1536hrs Japanese time, an explosion in the Unit 1 reactor building of Fukushima Daichi (I) power plant occurred. On 14th the same months at 11: 15 JST, an explosion in the same building occurred in the Reactor 3. At 16:14 JST the next day, another explosion took place in Unit 2 occurred, which destroyed the pressure-suppression system. Because of the disaster, reactor 4 was shut down completely for intermittent inspection and all the fuel dowels were moved to the upper floor of the reactor building. An explosion that occurred on 15 March destroyed the fourth floor roof of the unit 4 reactor.

The Japanese Red Crescent Society also engaged in rescue mission by providing temporary housing shelters and other equipment’s. The society performance on accommodation was outstanding for refugees and evacuees who were settled in schools, public buildings, and other shelters. Erection of provisional housing in the affected region began 8 days after the incident, which were ready in a period of 12 months. Special teams of medical practitioners, therapist and social workers, were also dispatched to the affected regions by the Health ministry whereby more focus was placed on psychotherapy unlike the initial physical therapy. The ministry also set up mechanisms aimed at controlling the spread of infectious diseases and encouraged the masses to use masks.

There were also incidences of fire, which were reported in eight regions in the aftermath of the earthquake. Fire dominance of gas pipeline lasted for few days in Cosmo Oil Installations and other refineries. The number fire up surged from 44 to around 325 in a week despite its growth rate declining. All the fires erupting as a result of the earthquake were under the control of the Japanese national police who worked tirelessly to extinguish them. The fires also caused a huge shortage of fuel supply in the affected areas caused by the slow gas pipes repairing process. The supply of about one million liter gasoline to the affected areas relied on tankers and ad cargo trains to curb the shortage in supply of fuel. There were erratic power shortages supply caused by the closure of power plants affected by the tsunami from the authorities, which affected the whole country. Large multinational organizations, such as Toyota and Sonny were forced to reduce the output and other activities due to limited power supply. Local citizens were also affected and reduced their power consumption to curtail blackout times.

Nuclear Catastrophe

In Japan, there were approximately 54 reactors. However, after the destruction of Fukushima plant by the tsunami in 2011, which elicited a world crisis in 25 years, the government did not restart any reactors due to public safety. All the eleven reactors in Fukushima, Onagawa, and Tokai nuclear power plants were shut down safely in the aftermath of the earthquake. Nevertheless, the influx of the tsunami with intensive voltage waves destroyed the reactors cooling systems and led to perilous explosions. This situation would have been controlled if the engineers had predicted a probable occurrence of such a high altitude incidence more cautiously. The explosions took place in 4 out of the total 6 reactors at Fukushima 1 Power plant while unit 3 was more hazardous affecting the entire surrounding. A few minutes before the explosion, the authorities tried to warn people and advised them to evacuate but it was too late.

The Fukushima plant is owned by the Tokyo Electric Power Company (TEPCO). The organization is blamed for not telling the truth about the hazardous damage it caused in the aftermath of the earthquake at the expense of saving its public image (16). According to the experts, the organization was supposed to shut down its reactors safely at Fukushima 1 nuclear power plant, almost a months before the occurrence of the earthquake, but deceptively, it assumed the warning due to fear of monetary losses. An approximately 140, 000 population was evacuated at a faraway distance 20Km radius from the plant. However, the radiations infiltrated foods and drinking water at a distance of 30Km from the evacuation region. The authorities were forced to stop the distribution of the affected foodstuffs (13). The United States Department of Energy noted with great concern the effects of the power plant that affected an estimated area of about 8- Km radius from the power plant installation (17). The explosion of this power plant in Japan was under scrutiny of the public and the government forced it to close all its nuclear reactors in 26 Mach 2012 for regular marinating and re installation.

Tohoku Earth Crisis Consequences

The Tohoku earthquake entailed massive destruction and environmental impacts that took time to recuperate. Besides the radioactive materials exposed to the environment as a result of the nuclear explosions, the following tsunamis filtrated in large amounts of fragments that caused a lot of harm to the environment. The radioactive pollution and threats caused a lot of fear to the residents, most of who refused to return to the regions affected after the evacuation.

Conclusion

The Tohoku earthquake and preceding tsunami of 11 Mach 2011 triggered Japan as a nation to come up with different mechanism that could help avoid huge casualties and destruction witnessed by this catastrophe. The infrastructure and buildings are mostly targeted in the approaches the nation is planning to implement in curbing the effects of such calamities. Were it for the earthquake alone, the country would not have gone through such a massive loss and impeding dangers. The nation failed in controlling the effects of the calamity because of economic consideration by the authorities rather that the moral factors that aggravated the situation.

This catastrophe, however, served as moral lesson to Japan and other nations across the globe to uninstall the old and unsafe operating power plants with new and safe ones. For instance, the Metsamor nuclear plant around Armenia and neighboring Iran was found to be very dangerous with a high seismic risk. The two nations invested in a long -term expensive solutions and replaced the plant with clean and renewable forms with regards to moral requirements and not economic values.

Despite the energy issue in the management of the power plant crisis being the blind spot in the Tohoku Earth Crisis, the nation’s handling of the disaster was highly commendable. In addition, the calm, patience, discipline, and cooperation from different agencies demonstrated a mature level of disasters handling capability, which is rare in developing societies.

This calamity also served as a warning to all nations around the globe, especially the seismologists to improve the methods of evaluation and estimation of plausible time for earthquakes. This improvement will help nations faced with the danger of impeding earthquakes to be cautious about the effects. Preparations are important in avoiding and minimizing the negative impacts of earthquakes. Every nation and society in the earthquake prone areas ought to determine how prepared they are in case of such occurrence to reduce the effects and casualties.

 

References

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Satake, K., Y. Fujii, T. Harada, and Y. Namegaya (2013). Time and space distribution of coseismic slip of the 2011.

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