• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.6
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• pp.689-696
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• 2020

It is known through prior research that the crust of the Korean Peninsula moves southeast at an annual average of 3 cm/year. The 2011 Great East Japan Earthquake caused a great change in the crust of the Korean Peninsula. Since then, the frequency of earthquakes has increased on the Korean Peninsula. Therefore, by using NGII and IGS GNSS observation data of the recent 15 years, to analyze the trends of changes in the deformation of the Korean Peninsula before and after the outbreak of the Great East Japan Earthquake. Data processing utilized Bernese Software V5.2, a widely used scientific and technical software around the world. As a result, the global movement of the Korean peninsula differed by about 4mm and the direction of movement by about 10° compared to before the Great East Japan Earthquake. As for the internal distortion of the Korean Peninsula, the East-West expansion of the Korean peninsula's crust was observed during the Great East Japan Earthquake, but it is believed that it has not fully returned to the level before the Great East Japan Earthquake.

• Journal of Contemporary Eastern Asia
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• v.12 no.2
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• pp.5-17
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• 2013

This paper discusses the future of journalism, including social-media use. The findings within this paper are based on the results of the "Social Survey on Social Media Use in the Great East Japan Earthquake." The author conducted this Internet-based survey in June 2012, and the results discussed herein are based on a sample size of 1,000 persons. The main findings suggest that social-media use during and immediately following the March 11, 2011 earthquake in Japan has been developing in a mutually complementary manner with traditional media.

• Fire Science and Engineering
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• v.32 no.5
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• pp.87-94
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• 2018

This study examined the role of volunteer fire fighters in coping with great disasters in terms of community-based disaster management to provide some implications from a qualitative comparative case study between Korea and Japan. Kobe, which suffered from the Great Hanshin-Awaji earthquake in 1995, was the study area. The city experienced an inadequate institutional system and lack of disaster management infrastructure at the time before the disaster. The study indicates that Korea volunteer fire fighters are not prepared sufficiently to tackle great disasters in terms of the supporting system, capacity and role by analyzing improvement plans of Japanese Volunteer Fire Fighters after Great East Japan earthquake in 2011. The results of the case study suggests improvements in the disaster management system to provide cooperation between the central government and local government, core task distribution, and community-based disaster management.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.331-332
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• 2022

After the Great East Japan Earthquake, reports and books that compiled the testimonies of the victims were published and the situation of the evacuation at that time became known. However, there is very little information on the evacuation situation of children among these data, and it is not fully known what actions the children took and how they evacuated due to an earthquake or tsunami. The purpose of this study is to analyze and examine children's evacuation behavior in the Great East Japan Earthquake, and to predict children's evacuation behavior for future disasters.

• Journal of the Korean earth science society
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• v.23 no.1
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• pp.112-118
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• 2002

The anomalous behaviour of animals prior to a large earthquake has been frequently reported from many places throughout the world since ancient times. This study is to experimentally testify what relations exist between the anomalous animal behavior and electric field effect, which is reported due to the piezo-electric effects in a basement rock before earthquake occurrences. We investigated the electric field effects on behaviors of two kinds of rats and birds. Rats show more sensitive anomalous behavior than birds. Even though the current applied to the experimental birds and rats is just a few ${\mu}$A, they show various abnormal behaviors. The anomalous animal behaviors under the small ground electric field may have some relations to the actual phenomena before great earthquake.

• 한국방재학회:학술대회논문집
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• 2009.02b
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• pp.165.2-165.2
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• 2009

• Earthquakes and Structures
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• v.8 no.4
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• pp.889-913
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• 2015

Structural vibration characteristics of a semi-active base-isolated building were investigated using seismic observation records including those of the 2011 Great East Japan earthquake (Tohoku earthquake). Three different types of analyses were conducted. First, we investigated the long-term changes in the natural frequencies and damping factors by using an ARX model and confirmed that the natural frequency of the superstructure decreased slightly after the main shock of the Tohoku earthquake. Second, we investigated short-term changes in the natural frequencies and damping factors during the main shock by using the N4SID method and observed different transition characteristics between the first and second modes. In the second mode, in which the superstructure response is most significant, the natural frequency changed depending on the response amplitude. In addition, at the beginning of the ground motion, the identified first natural frequency was high possibly as a result of sliding friction. Third, we compared the natural frequencies and damping factors between the conditions of a properly functional semi-active control system and a nonfunctional system, by using the records of the aftershocks of the Tohoku earthquake. However, we could not detect major differences because the response was probably influenced by sliding friction, which had a more significant effect on damping characteristics than did the semi-active dampers.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.10a
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• pp.281-288
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• 1999

This paper studied the efficiency of retrofitting of reinforced concrete structure which was not designed to endure an earthquake. The earthquake in Kobe Japan showed that there was a great possibility of having an earthquake even in big city and the damages were concentrated on mid or low story buildings which were not considered to be protected from an earthquake, . This experiment used reinforced concrete structure which restrained side-by-side displacement to test durability against an earthquake. This study deals with the structural performance of reinforced concrete frame structures strengthened with steel materials.

• Journal of the Earthquake Engineering Society of Korea
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• v.25 no.5
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• pp.223-232
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• 2021

The spatial variation characteristics of seismic motions at the nuclear power plant's site and structures were analyzed using earthquake records obtained at the Fukushima nuclear power plant during the Great East Japan Earthquake. The ground responses amplified as they approached the soil surface from the lower rock surface, and the amplification occurred intensively at about 50 m near the ground. Due to the soil layer's nonlinear characteristics caused by the strong seismic motion, the ground's natural frequency derived from the response spectrum ratio appeared to be smaller than that calculated from the shear wave velocity profile. The spatial variation of the peak ground acceleration at the ground surface of the power plant site showed a significant difference of about 0.6 g at the maximum. As a result of comparing the response spectrums at the basement of the structure with the design response spectrum, there was a large variability by each power plant unit. The difference was more significant in the Fukushima Daiichi site record, which showed larger peak ground acceleration at the surface. The earthquake motions input to the basement of the structure amplified according to the structure's height. The natural frequency obtained from the recorded results was lower than that indicated in the previous research. Also, the floor response spectrum change according to the location at the same height was investigated. The vertical response on the foundation surface showed a significant difference in spectral acceleration depending on the location. The amplified response in the structure showed a different variability depending on the type of structure and the target frequency.

• Journal of the Korean Geographical Society
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• v.47 no.5
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• pp.700-717
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• 2012

This study aims to discuss the spatial issues of disaster recovery from the Great East Japan Earthquake. Focused on tsunami-damaged regions, this study examines how major regional development issues have been dealt with. In the case study areas, the following ideal spatial methodologies have been suggested for tsunami recovery: building a compact city, intensifying fishing villages, and making a sustainable city. However, as the spatial restructuring have encountered practical barriers, reconstruction has been delayed, and the regional decline have been accelerating. To prevent regional decline which is inevitable after a disaster, this paper suggests that the area of disaster studies should be expanded to long-term recovery process beyond emergency response.