Investigation of Damages in Immediate Vicinity of Co-Seismic Faults During the 2016 Kumamoto Earthquake

2017 ◽  
Vol 12 (5) ◽  
pp. 899-915 ◽  
Author(s):  
Shohei Naito ◽  
Ken Xiansheng Hao ◽  
Shigeki Senna ◽  
Takuma Saeki ◽  
Hiromitsu Nakamura ◽  
...  
Keyword(s):  
Fault Zone ◽  
Active Fault ◽  
Strong Motion ◽  
Site Amplification ◽  
Building Damage ◽  
2016 Kumamoto Earthquake ◽  
Severe Damage ◽  
Kumamoto Earthquake ◽  
The 2016 Kumamoto Earthquake ◽  
The Relationship

In the 2016 Kumamoto earthquake, the Futagawa fault zone and the Hinagu fault zone were active in some sections, causing severe damage in neighboring areas along the faults. We conducted a detailed investigation of the surface earthquake fault, building damage, and site amplification of shallow ground within about 1 km of the neighboring areas of the fault. The focus was mainly on Kawayou district, Minamiaso village and Miyazono district, Mashiki town, and locations that suffered particularly severe building damage. We explored the relationship between local strong motion and building damage caused in areas that were in the immediate vicinity of the active fault.

scholarly journals Seismic velocity structure at the southern termination of the 2016 Kumamoto Earthquake rupture, Japan

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Yasuhira Aoyagi ◽  
Haruo Kimura ◽  
Kazuo Mizoguchi
Keyword(s):  
Fault Zone ◽  
Velocity Structure ◽  
Seismic Velocity ◽  
Earthquake Rupture ◽  
2016 Kumamoto Earthquake ◽  
Seismic Velocity Structure ◽  
Kumamoto Earthquake ◽  
Seismogenic Layer ◽  
The 2016 Kumamoto Earthquake ◽  
Tectonic Line

Abstract The earthquake rupture termination mechanism and size of the ruptured area are crucial parameters for earthquake magnitude estimations and seismic hazard assessments. The 2016 Mw 7.0 Kumamoto Earthquake, central Kyushu, Japan, ruptured a 34-km-long area along previously recognized active faults, eastern part of the Futagawa fault zone and northernmost part of the Hinagu fault zone. Many researchers have suggested that a magma chamber under Aso Volcano terminated the eastward rupture. However, the termination mechanism of the southward rupture has remained unclear. Here, we conduct a local seismic tomographic inversion using a dense temporary seismic network to detail the seismic velocity structure around the southern termination of the rupture. The compressional-wave velocity (Vp) results and compressional- to shear-wave velocity (Vp/Vs) structure indicate several E–W- and ENE–WSW-trending zonal anomalies in the upper to middle crust. These zonal anomalies may reflect regional geological structures that follow the same trends as the Oita–Kumamoto Tectonic Line and Usuki–Yatsushiro Tectonic Line. While the 2016 Kumamoto Earthquake rupture mainly propagated through a low-Vp/Vs area (1.62–1.74) along the Hinagu fault zone, the southern termination of the earthquake at the focal depth of the mainshock is adjacent to a 3-km-diameter high-Vp/Vs body. There is a rapid 5-km step in the depth of the seismogenic layer across the E–W-trending velocity boundary between the low- and high-Vp/Vs areas that corresponds well with the Rokkoku Tectonic Line; this geological boundary is the likely cause of the dislocation of the seismogenic layer because it is intruded by serpentinite veins. A possible factor in the southern rupture termination of the 2016 Kumamoto Earthquake is the existence of a high-Vp/Vs body in the direction of southern rupture propagation. The provided details of this inhomogeneous barrier, which are inferred from the seismic velocity structures, may improve future seismic hazard assessments for a complex fault system composed of multiple segments.

Using Agent Simulations to Evaluate the Effect of a Regional BCP on Disaster Response

2018 ◽  
Vol 13 (2) ◽  
pp. 387-395 ◽  
Author(s):  
Zijian Liu ◽  
Takeyasu Suzuki ◽  
◽  
◽  
Keyword(s):  
Quantitative Analysis ◽  
Disaster Response ◽  
Distribution Center ◽  
Business Continuity ◽  
2016 Kumamoto Earthquake ◽  
Severe Damage ◽  
Economic Activities ◽  
Kumamoto Earthquake ◽  
The 2016 Kumamoto Earthquake ◽  
Private Corporations

The 2016 Kumamoto earthquake caused severe damage to economic activities and livelihood of residents by disrupting the supply chains of common resources, such as food, water, roads, and other infrastructure. This disaster has made recovery difficult for businesses in the region. The importance of addressing BCP in regional areas was made clear by the 2004 Niigataken Chuetsu earthquake and the 2007 Niigataken Chuetsu-oki earthquake. The 2011 Greate East Japan earthquake revealed that individual business continuity efforts were interrupted by disruption of common infrastructure. Therefore, a new concept of a region-wide business continuity plans (BCP) that focuses on collaboration among stakeholders, including private corporations, local government, and communities, was urgently required to enhance the resilience of the region against disasters. A new concept of Area BCP was proposed by JICA and Prefectural-scale District BCP was formulated by prefectural governments of Kyoto and Kagawa.In order to evaluate the effect of the presence of a regional BCP on disaster response, this study focuses on one of the most important elements of a regional BCP: the disaster relief chain information-sharing factor. Based on the supply of relief goods from the distribution center in Tosu City, Saga Prefecture to the evacuation centers in Kumamoto Prefecture during the Kumamoto earthquake, the evaluation was conducted by quantitative analysis using agent simulations of relief logistics.

The Importance of Seismic Death Risk Assessment of Households in the Kumamoto Earthquake of 2016

2017 ◽  
Vol 12 (6) ◽  
pp. 1151-1160 ◽  
Author(s):  
Tadayoshi Nakashima ◽  
◽  
Shigeyuki Okada ◽  
Akane Shinoda
Keyword(s):  
Risk Assessment ◽  
Decision Making ◽  
Building Damage ◽  
2016 Kumamoto Earthquake ◽  
Death Risk ◽  
Kumamoto Earthquake ◽  
The 2016 Kumamoto Earthquake ◽  
Return Home ◽  
Reduction Effect ◽  
Over Time

This paper discusses the reduction effect of a foreshock on casualties during the mainshock of people who evacuated to shelters and their private cars during the 2016 Kumamoto earthquake. In the first part of this paper, we discuss the number of human casualties caused by the collapse of wooden buildings. The characteristics of casualties in the Kumamoto earthquake are classified as household attributes and building damage caused by the foreshock and mainshock. In the second part, we apply equations (Nakashima and Okada 2008 and Okada and Nakashima 2015) to the Masiki area to determine the total number of casualties with a focus on deaths. The number of deaths due to total building damage from the foreshock and the mainshock in the case of 0 evacuees was estimated as 147. We then estimated the reduction effect on the number of casualties caused by the foreshock by using the survey data of the mainshock and foreshock. We found that evacuation during the mainshock decreased the death toll by 128 people. Moreover, the number of injured people decreased by 657. Generally, most people who evacuate tend to return home over time. As a result, many people die at the time of a subsequent mainshock. It is important to provide death risk information to each household to support their decision-making regarding appropriate evacuation.

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