Has 20 Years of Japanese Earthquake Research Enhanced Seismic Disaster Resilience in Kumamoto?

2017 ◽  
Vol 12 (6) ◽  
pp. 1098-1108 ◽  
Author(s):  
Naoshi Hirata ◽  

It has been about 20 years since the Headquarters for Earthquake Research Promotion (HERP) was established following the Great Hanshin-Awaji Earthquake Disaster. Now the time has come to examine its contributions to disaster resilience. On April 14 and 17, 2016, a series of large earthquakes, including M6.5 and M7.3 events, occurred in Kumamoto Prefecture in Kyushu, Japan. More than 200 fatalities and 8,600 totally collapsed houses were reported. The earthquakes occurred on known active faults, which were assessed by the Earthquake Research Committee (ERC) before the events. The regional disaster management plan by Kumamoto Prefecture had predicted the events reported by the ERC and estimated damages at about the same level as what was actually seen. However, even though the estimate was accurate, the countermeasures were insufficient: the local people still did not seriously expect a large earthquake to strike in their local area, and their efforts to enhance the disaster resilience of the Kumamoto area were insufficient. This suggests that the efforts by the HERP were not sufficient to make the local community resilient enough to withstand a large earthquake.

2020 ◽  
Vol 91 (3) ◽  
pp. 1384-1393 ◽  
Author(s):  
Kenji Satake ◽  
Hiroshi Tsuruoka ◽  
Satoko Murotani ◽  
Kenshiro Tsumura

Abstract The Earthquake Research Institute (ERI) of the University of Tokyo maintains archives of analog seismograms and mareograms. The main collection is ∼236,000 Japanese historical seismograms recorded at the University of Tokyo (at various buildings and using various instruments around Hongo [Tokyo] with a total of 189,000 records from 1881 to 1993), at the Tsukuba observatory (∼11,000 records from 1921 to 1986), and at the Wakayama seismological network (∼12,650 records from 1928 to 1968). Seismograms recorded by temporal stations at various locations in Japan for several years, typically following large earthquakes, are also included. Different types of instruments were used to record the data. The oldest record from a large earthquake is from the 1891 Nobi earthquake recorded at Hongo on a circular seismogram using an Ewing-type seismograph. Teleseismic seismograms include those from the 1899 Alaska earthquake at Hongo on an Omori-type seismograph. Imamura-type and Omori-type tremometers and strong-motion seismographs had also been used for a long time. While these seismograms were microfilmed by the 1990s, the original smoked paper records have also been archived. Foreign seismogram collections include those from earthquakes in Taiwan between 1904 and 1917 recorded in both Japan and Taiwan and those from the Canadian Seismograph Network between 1981 and 1989. For the Worldwide Standardized Seismograph Network stations, almost all (∼5,000,000) microfilm records at 167 stations from 1963 to 1988 are archived. High-resolution image scanning of analog daily seismograms at the Wakayama microearthquake network is currently being performed, and the scans are provided using Leaflet software so that the users can easily access and enlarge parts of seismograms. The tsunami waveform archive contains ∼3100 records on Japanese tide gauges from large earthquakes between 1911 and 1996. The available data, with dates and types of instruments, can be searched from the database through the website of the ERI.


2021 ◽  
Author(s):  
Ruth Harris ◽  
Michael Barall ◽  
David Ponce ◽  
Diane Moore ◽  
Russell Graymer ◽  
...  

<p>The Rodgers Creek-Hayward-Calaveras-Northern Calaveras fault system in California dominates the hazard posed by active faults in the San Francisco Bay Area. Given that this fault system runs through a densely populated area, a large earthquake in this region is likely to affect millions of people. This study produced scenarios of large earthquakes in this fault system, using spontaneous (dynamic) rupture simulations. These types of physics-based computational simulations require information about the 3D fault geometry, physical rock properties, fault friction, and initial stress conditions. In terms of fault geometry, the well-connected multi-fault system includes the Hayward fault, at its southern end the Central and Northern Calaveras faults, and at its northern end the Rodgers Creek fault. Geodetic investigations of the fault system’s slip-rate pattern provide images of where the fault surfaces at depth are creeping or locked interseismically, and this helped us choose appropriate initial stress conditions for our simulations. A 3D geologic model of the fault system provides the 3D rock units and fault structure at depth, while field samples from rocks collected at Earth’s surface provide frictional parameters. We used this suite of information to investigate the behavior of large earthquake ruptures nucleating at various positions along this partially creeping fault system. We found that large earthquakes starting on the Hayward fault or on the Rodgers Creek fault may be slowed, stopped, or unaffected in their progress, depending on how much energy is released by the creeping regions of the Hayward and Central Calaveras faults during the time between large earthquakes. Large earthquakes starting on either the Hayward fault or the Rodgers Creek faults will likely not rupture the Northern Calaveras fault, and large earthquakes starting on either the Northern Calaveras fault or the Central Calaveras fault will likely remain confined to those fault segments.</p>


2020 ◽  
Vol 40 (1) ◽  
pp. 1-16
Author(s):  
Vivienne Dunstan

McIntyre, in his seminal work on Scottish franchise courts, argues that these courts were in decline in this period, and of little relevance to their local population. 1 But was that really the case? This paper explores that question, using a particularly rich set of local court records. By analysing the functions and significance of one particular court it assesses the role of this one court within its local area, and considers whether it really was in decline at this time, or if it continued to perform a vital role in its local community. The period studied is the mid to late seventeenth century, a period of considerable upheaval in Scottish life, that has attracted considerable attention from scholars, though often less on the experiences of local communities and people.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Yoshihisa Iio ◽  
Satoshi Matsumoto ◽  
Yusuke Yamashita ◽  
Shin’ichi Sakai ◽  
Kazuhide Tomisaka ◽  
...  

AbstractAfter a large earthquake, many small earthquakes, called aftershocks, ensue. Additional large earthquakes typically do not occur, despite the fact that the large static stress near the edges of the fault is expected to trigger further large earthquakes at these locations. Here we analyse ~10,000 highly accurate focal mechanism solutions of aftershocks of the 2016 Mw 6.2 Central Tottori earthquake in Japan. We determine the location of the horizontal edges of the mainshock fault relative to the aftershock hypocentres, with an accuracy of approximately 200 m. We find that aftershocks rarely occur near the horizontal edges and extensions of the fault. We propose that the mainshock rupture was arrested within areas characterised by substantial stress relaxation prior to the main earthquake. This stress relaxation along fault edges could explain why mainshocks are rarely followed by further large earthquakes.


Author(s):  
Kazuki Karashima ◽  
Akira Ohgai

To minimize the damage caused by large earthquakes, mutual assistance activities between residents and rescue victims (i.e., to support residents who cannot evacuate individually) are important. To enhance these activities, the technologies and methods for creating a Community Disaster Management Plan (CDMP), based on the quantitative evaluation of mutual assistance abilities, are required. However, the lack of a method for it is a key issue. This study aims to develop a methodology of workshops for making CDMPs by using the developed support tool by the authors to explore and promote mutual assistance activities. Through the demonstration and examination of a Community Disaster Management Plan on actual districts, the findings mentioned in this article were obtained. Moreover, the usability of this method is shown. In particular, this method is effective at revising CDMPs, and raising resident awareness on the importance of mutual assistance. The suggested method can also improve the lack of techniques involved in promoting mutual assistance.


2009 ◽  
Vol 03 (02) ◽  
pp. 77-88 ◽  
Author(s):  
HASANUDDIN Z. ABIDIN ◽  
HERI ANDREAS ◽  
TERUYUKI KATO ◽  
TAKEO ITO ◽  
IRWAN MEILANO ◽  
...  

Along the Java trench the Australian–Oceanic plate is moving and pushing onto and subducting beneath the Java continental crust at a relative motion of about 70 mm/yr in NNE direction. This subduction-zone process imposed tectonic stresses on the fore-arc region offshore and on the land of Java, thus causing the formation of earthquake fault zones to accommodate the plate movement. Historically, several large earthquakes happened in Java, including West Java. This research use GPS surveys method to study the inter-seismic deformation of three active faults in West Java region (i.e. Cimandiri, Lembang and Baribis faults), and the co-seismic and post-seismic deformation related to the May 2006 Yogyakarta and the July 2006 South Java earthquakes. Based on GPS surveys results it was found that the area around Cimandiri, Lembang and Baribis fault zones have the horizontal displacements of about 1 to 2 cm/yr or less. Further research is however still needed to extract the real inter-seismic deformation of the faults from those GPS-derived displacements. GPS surveys have also estimated that the May 2006 Yogyakarta earthquake was caused by the sinistral movement of the (Opak) fault with horizontal co-seismic deformation that generally was less than 10 cm. The post-seismic horizontal deformation of the July 2006 South Java tsunami earthquake has also been estimated using GPS surveys data. In the first year after the earthquake (2006 to 2007), the post-seismic deformation is generally less than 5 cm; and it becomes generally less than 3 cm in the second year (2007 to 2008).


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Quan Sun ◽  
Shunping Pei ◽  
Zhongxiong Cui ◽  
Yongshun John Chen ◽  
Yanbing Liu ◽  
...  

AbstractDetailed crustal structure of large earthquake source regions is of great significance for understanding the earthquake generation mechanism. Numerous large earthquakes have occurred in the NE Tibetan Plateau, including the 1920 Haiyuan M8.5 and 1927 Gulang M8 earthquakes. In this paper, we obtained a high-resolution three-dimensional crustal velocity model around the source regions of these two large earthquakes using an improved double-difference seismic tomography method. High-velocity anomalies encompassing the seismogenic faults are observed to extend to depths of 15 km, suggesting the asperity (high-velocity area) plays an important role in the preparation process of large earthquakes. Asperities are strong in mechanical strength and could accumulate tectonic stress more easily in long frictional locking periods, large earthquakes are therefore prone to generate in these areas. If the close relationship between the aperity and high-velocity bodies is valid for most of the large earthquakes, it can be used to predict potential large earthquakes and estimate the seismogenic capability of faults in light of structure studies.


2021 ◽  
Vol 5 (2) ◽  
pp. 193
Author(s):  
Muh. Fakhri Jamaluddin ◽  
Mohamad Sapari Dwi Hadian ◽  
Awaludin Nugraha

The rapid development of Bali tourism sector, especially in the tourist area of Lake Batur, lead to many changes in community cultural patterns. Several issues, such as the transition of space functions and the development of tourism designations, have not considered the environmental, economic, social and cultural conditions in the local area. Several regional policies were established in order to maintain the local wisdom of the Hindu-Balinese community and become the basis for organizing tourism in Bali. The availability of open space in a tourist attraction in an destination can be a supporting factor for tourists and local communities. This was a qualitative descriptive study. This method aims to obtain an in-depth description regarding the forms of local wisdom of the Hindu-Balinese community which contain the elements of balance which further be adjusted into spatial planning. A sustainable tourist park may be a site for the activities and interaction among local community, tourists, and also be able to become a forum for education regarding Balinese culture and the natural environment, both of which need to be preserved for the sustainability of Lake Batur tourist area which has a great potential in the development of tourism sector.


2001 ◽  
Vol 25 (2) ◽  
pp. 275-317
Author(s):  
Sudhir Venkatesh

Chicago is amythic city. Its representation in the popular imagination is varied and has included, at various times, the attributes of a blue-collar town, a city in a garden, and a gangster's paradise. Myths of Chicago “grow abundantly between fact and emotion,” and they selectively and simultaneously evoke and defer attributes of the city. For one perduring myth, social scientists may be held largely responsible: namely, that Chicago is “one of the most planned cities of themodern era,” with a street grid, layout of buildings and waterways, and organization of its residential and commercial architecture that reveal a “geometric certainty” (Suttles 1990). The lasting scholarly fascination with Chicago's geography derives in part from the central role that social scientists played in constructing the planned city. In the 1920s,University of Chicago sociologist Ernest Burgess worked with his colleagues in other social science disciplines to divide the city into communities and neighborhoods. This was a long and deliberate process based on large-scale “social surveys” of several thousand city inhabitants.Their work as members of the Local Community Research Committee (LCRC) produced the celebrated Chicago “community area”—that is, 75 mutually exclusive geographic areas of human settlement, each of which is portrayed as being socially and culturally distinctive.


2021 ◽  
Author(s):  
Abeer Al-Ashkar ◽  
Antoine Schlupp ◽  
Matthieu Ferry ◽  
Ulziibat Munkhuu

Abstract. We present new constraints from tectonic geomorphology and paleoseismology along the newly discovered Sharkhai fault near the capital city of Mongolia. Detailed observations from high resolution Pleiades satellite images and field investigations allowed us to map the fault in detail, describe its geometry and segmentation, characterize its kinematics, and document its recent activity and seismic behavior (cumulative displacements and paleoseismicity). The Sharkhai fault displays a surface length of ~40 km with a slightly arcuate geometry, and a strike ranging from N42° E to N72° E. It affects numerous drainages that show left-lateral cumulative displacements reaching 57 m. Paleoseismic investigations document the faulting and deposition record for the last ~3000 yr and reveal that the penultimate earthquake (PE) occurred between 1515 ± 90 BC and 945 ± 110 BC and the most recent event (MRE) occurred after 860 ± 85 AD. The resulting time interval of 2080 ± 470 years is the first constraint on the Sharkhai fault for large earthquakes. On the basis of our mapping of the surface rupture and the resulting segmentation analysis, we propose two possible scenarios for large earthquakes with likely magnitudes between 6.4 ± 0.2 and 7.1 ± 0.2. Furthermore, we apply scaling laws to infer coseismic slip values and derive preliminary estimates of long-term slip rates between 0.2 ± 0.2 and 1.0 ± 0.5 mm/y. Finally, we propose that these original observations and results from a newly discovered fault should be taken into account for the seismic hazard assessment for the city of Ulaanbaatar and help build a comprehensive model of active faults in that region.


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