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1.
Households vary in their ability to deal with disasters, and this may lead to different recovery results. Aiming to examine this differentiation, this paper studied the 2009 Yao??an earthquake in China. Surveys of 200 destroyed rural households were conducted in field investigations and follow-ups at 1?month, 1?year, and 1.5?years after the earthquake. The results showed a clear difference in recovery, the households observably being classified into five groups. These are the O group, which has different recovery time and economic cost from the other four; and the special group, comprising E L T O and E O T L (vulnerable during recovery); E H T O (strong during recovery); and E L T S (neither vulnerable nor strong). Logistic regression analysis revealed that differentiation in recovery patterns arose from the combined effect of demographic factors and external assistance provided to households. Lower income is the root cause of vulnerability in some households during the recovery process. However, other factors cause recovery differences between the two vulnerable groups, causing the economic recovery cost of the E L T O group to be lower, and the recovery time of the E O T L group to be longer. There was consensus that external assistance had an impact on all households. The more provided and the earlier it arrived, the lower the cost for recovery and the shorter the recovery time. This study shows that research on group differentiation of recovery is useful in understanding post-earthquake recovery processes and calls for taking group differentiation considerations into account in post-disaster recovery resource allocation practices.  相似文献   

2.
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3.
Butler  Rhett 《Natural Hazards》2019,96(2):961-973

High-frequency (5–20 Hz) seismic signals precursory to and embedded within the June 17, 2017 ML?=?4 earthquake–landslide event are analyzed. This event in western Greenland generated a tsunami in Karrat fjord inundating Nuugaatsiaq village 32 km distant. Spectrogram and wavelet analyses of seismic data from the Greenland Ice Sheet Monitoring Network (GLISN) corroborate observations of seismic precursors at Nuugaatsiaq reported by Poli (Geophys Res Lett 44:8832–8836, 2017) and Caplan-Auerbach (in: AGU fall meeting abstracts, 2017) and reveal additional high-frequency arrivals being generated after the apparent initiation of fault rupture. New observations of seismic precursors 181 km from the Event at Upernavik, Greenland are correlated with those seen at Nuugaatsiaq. Wavelet analysis presents?>?100 significant energy peaks accelerating up to and into the earthquake–landslide event. The precursor events show a distinct, power law distribution, characterized by b values of ~?2.4. Results are compared and contrasted with small precursors observed in the studies of a natural chalk cliff landslide at Mesnil-Val, Haute Normandie, France. The earthquake–landslide appears to have been initiated by seismic precursors located at the fault scarp, leading to a small seismic foreshock and small landslide initiation, followed by a larger earthquake at the fault scarp, precipitating the primary landslide into the Karrat Fjord, which caused the subsequent tsunami.

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4.
This paper reports the results of field observation and the study of coastal tectonic deformations related to the Nevelsk tsunamigenic earthquake (August 2, 2007, M ～ 6.1) obtained in August-September of 2007. The earthquake caused a 0.5- to 1.5-m rise of and partial desiccation of the southern, central, and northern benches and the formation of longitudinal structural ridges seaward of Lovetskaya Bay. In the framework of the new model of the Kamyshovy (West Sakhalin) Anticlinorum as a structure of the Quaternary and Middle Quaternary crustal detachment, the relationships between the earthquake and the slow gravitational creep of the upper crust on its western slope with local squeezing of the Middle Miocene Nevelsk siltstones are discussed.  相似文献   

5.
Reconnaissance observations are presented on the building damage caused by the May 19, 2011, Kütahya–Simav earthquake in Western Turkey as well as an overview of strong ground motion data recorded during the earthquake is given. According to Disaster and Emergency Management Presidency of Turkey, the magnitude of the earthquake is 5.7 in local magnitude scale. Although the earthquake can be regarded as a moderate event when considering its magnitude and strong motion recordings, it caused excessive structural damage to buildings in Simav district and several villages in the near vicinity. During the field investigation, different types of structural damage were observed mainly in the reinforced concrete frame buildings with infill walls and masonry buildings with various types of construction materials. Observed damage resulted from several deficiencies in structural and non-structural components of the buildings. Poor construction materials and workmanship, non-conforming earthquake-resistant design and construction techniques and non-ductile detailing are the main reasons for such an extensive damage, as observed in many past earthquakes in Turkey.  相似文献   

6.
On the 21st of April 2007, the Aysén Fjord earthquake (Mw 6.2) in southern Chile (45.3° S, 73.0° W) triggered hundreds of landslides in the epicentral area along the fjord coast and surroundings. Some of these landslides induced large tsunami waves within the fjord causing fatalities and damaging several salmon farms, the most important economic activity of the area. The landslides included rock slides and avalanches, rock falls, shallow soil and soil–rock slides, and debris flows. The earthquake was the climax of a seismic swarm that began 3 months earlier. The seismicity is associated with tectonic activity along the Liquiñe–Ofqui fault zone (LOFZ), a major structural feature of the region. The earthquake-induced landslides were mapped and classified from field observations and remote sensing analysis. The landslide areas and epicentral distances are within the expected range for the earthquake magnitude according to worldwide data, while the position of landslides on the slopes strongly suggests topographic amplification effects in triggering the failures. The location of the landslides is also clearly related to some of the main fault branches of the LOFZ. The seismic event has configured a new situation of seismic and landslide hazard in the Aysén region and along the LOFZ, where the presence of towns and economic infrastructure along the coasts of several fjords constitutes a potential risk that was not considered before this seismic event.  相似文献   

7.
Empirical Green??s function (EGF) technique is considered to be most effective technique for simulation of ground motions due to a finite earthquake source. In the present paper, this technique has been used to simulate ground motion due to a great earthquake. The coastal region of Sumatra Island has been visited by a great earthquake on December 26, 2004. This earthquake has been recorded at several broadband stations including a nearest broadband station PSI in Indonesia. The shear wave contributions in both horizontal components have been simulated at PSI station using EGF technique. The comparison of simulated and observed waveform has been made for various possibilities of rupture parameters in terms of root mean square error. The final rupture model supports rupture velocity of 3.0?km/s with nucleation point supporting northward propagating rupture that coincide with high-slip asperity defined by Sorensen et al. (Bull Seism Soc Am 97:S139?CS151, 2007). The final modeling parameters have been used to simulate record at MDRS station in coastal state of Tamilnadu, India. In an attempt to model a scenario of great earthquake in the Andaman Island, a hypothetical rupture plane is modeled in this region. The event occurred on August 10, 2008 of magnitude 6.2 (M w ) recorded on strong motion array at Port Blair has been used as EGF to simulate records due to the hypothetical great earthquake. Possibilities of earthquake due to the oblique strike-slip and thrust mechanism have been modeled in the present paper. Several possibilities of nucleation point for both cases has been considered, and it is seen that variation of peak ground acceleration at Port Blair station for strike-slip and thrust mechanism is 126?C738 gals and 647?C2,571 gals, respectively, which indicate high seismic hazard potential of Andaman Island.  相似文献   

8.
On June 14 2008, an Iwate–Miyagi inland earthquake that had a magnitude of 7.2 hit the eastern foot of the Ohu Mountains in Tohoku district, Japan. The seismic peak ground acceleration was greater than 1,000 gal in the Aratozawa Dam area. The earthquake triggered a massive landslide at the upper reach of the dam. The landslide had the sediment volume of over 67 million cubic meters and is considered the largest catastrophic landslide in Japan during the last 100 years. This report presents a summary of our findings pertinent to the landslide’s activities based on our field investigations that started the day after the landslide. This report covers: (1) details of the land deformations caused by the landslide, (2) geological background pertinent to landslide development, and (3) estimation of the slip surface and the other physical properties of the landslide based on the analysis of the boring core specimens and landform features. The landslide is roughly divided into two sections, a lower and an upper half. The lower half moved almost simultaneously as one massive block of 700 m long, 800 m wide, and 70–80 m thick. The slip surface had developed on the very fine sand of the alternate layer of fine-grained sandstone and siltstone. The slickensided slip surface has a gradient of only 2°. This feature indicates that the type of the landslide movement is considered to be a block glide. The landslide body is nearly identical to the topography of the landslide area that was developed about 50,000 years ago. This shows the possibility that the landslide was reactivated. The upper half consists of two large ridges and the broad debris field and is 600 m long, 900 m wide, and 70–100 m thick. The maximum height of the main scarp is over 150 m.  相似文献   

9.
An extraordinarily strong and persistent earthquake swarm (Andaman swarm 2005) originated in the Andaman back-arc following the aftershock sequences of the 26 December 2004 Sumatra earthquake. The swarm (n = 651, mbmax= 5.9) came mainly in two phases: January 26–31 and Feb.–Aug. 2005, in an area of size 90 × 40 km2, at the centre of which lies a broad bathymetric depression and high gravity zone. The swarm demonstrates a complex faulting series, initially the strike-slip motion followed by normal faulting in repetitive sequences, whose representative fault planes orient at high angle to the regional faults. The swarm character as well as the distribution of stress-axes and their correlation to tectonic features lends speculation for formation of a nascent rift segment in NW-SE direction at the doorstep of the Sewell Seamount. The swarm has given rise to 21 episodes of rifting activities of variable time extent within 26–31 January 2005. The r-t plots corresponding to the swarm data, modelled with variable hydraulic diffusivity (D) values 4, 6, 8 and 10 m2/s, suggest for excess pressure front from ascending magmatic fluid. This eventually heralded the rifting; causing pore pressure perturbations that propagated in accordance with known diffusion parabolic equations.  相似文献   

10.
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11.
The Galeras volcanic complex, located in the Nariño department, SW Colombia, includes the most historically active volcano in the country, Galeras, a 4276 m high stratovolcano located 9 km west of the city of San Juan de Pasto (400,000 inhabitants). The area is also affected by the continental faulting represented by the Buesaco, Aranda and Pasto faults belonging to one of the most seismically active structures in Colombia, the Romeral fault system. Several moderate to strong shallow earthquakes affected the city of San Juan de Pasto and its neighbouring region since the XVII century. The coexistence of an active volcanic complex and an active fault system complicates the study and interpretation of the different processes taking place in the region as well as the identification of any connection or interaction among them.The reactivation of the volcano in 1989 was characterized by three main magmatic events: (1) a series of Vulcanian eruptions during 4–9 May 1989, with semi-continuous ash emissions from a secondary crater; (2) the emplacement of an andesitic lava dome at the bottom of the main crater from September 1990 until December 1991; and (3) six Vulcanian eruptions from the main crater during 1992–1993, with destruction of most of the dome during the first one on 16 July 1992. During the same period, four earthquake sequences were located in a limited area N and NE of Galeras volcano on August–September 1989 (AUG1989), April–June 1993 (APR1993), November–December 1993 (NOV1993) and March–August 1995 (MAR1995). The last one included a Ml4.7 main shock on 4 March 1995 producing moderate to high damage in the epicentral region (MSK maximum intensity VIII), and in the city of San Juan de Pasto (VI–VII). The last damaging earthquake in the region was a MSK-intensity VIII–IX in 1947.A detailed analysis of the spatio-temporal characteristics of the four earthquake sequences allowed identifying their different origin and suggesting some interrelationship between the reactivated eruptive process and the contemporaneous seismic activity. The AUG1989 sequence presents a typical volcanic swarm-like pattern most probably related with the process of magma intrusion from depth at the beginning of the volcano's reactivation. The APR1993, the NOV1993 and the MAR1995 sequences show a clear tectonic origin with events occurring on rupture planes almost vertical that can be associated to the active faults in the area, The seismogenic process of these three sequences could have been activated or accelerated by the main eruptions during 1992–1993.These results suggest that constrains provided by improved relocations and the detailed analysis of the space–time characteristics of earthquake sequences in Galeras volcanic environment allow to establish the different generation mechanisms involved and to suggest feasible explanations on the possible interrelationships of the magmatic–volcanic processes and the seismicity observed.  相似文献   

12.
Abstract

The NE-SW-trending Burdur–Fethiye fault zone is one of the major active fault zones of southwestern Turkey and the ancient city of Cibyra is located on this zone. Segments of the Burdur–Fethiye fault zone have ruptured in the historical period and during the 20th century. A detailed investigation in the ancient city of Cibyra showed the presence of faults sinistrally offset sitting rows of the stadium up to 50 cm. In addition, there are broken corners of blocks, collapsed walls, broken columns, and tilted and toppled blocks in existing major buildings in the city centre. Field observations showed that fractures and associated damage at Cibyra Produced by a post-Roman earthquake, possibly during the 417-A.D.-earthquake which had an intensity of 9 on the MSK scale. © 2001 Éditions scientifiques et médicales Elsevier SAS.  相似文献   

13.
The 26 December 2004 earthquake and tsunami unfairly hit the different ethnic groups of Aceh, Indonesia. About 170,000 Acehnese and Minangkabau people died in the Northern tip of Sumatra while only 44 Simeulue people passed away in the neighbouring Simeulue island located near the earthquake epicentre. Such a difference in the death toll does not lie in the nature of the hazard but in different human behaviours and ethnic contexts. The present study draws on a contextual framework of analysis where people’s behaviour in the face of natural hazards is deeply influenced by the cultural, social, economic and political context. Questionnaire-based surveys among affected communities, key informant interviews and literature reviews show that the people of Simeulue detected the tsunami very early and then escaped to the mountains. On the other hand, Acehnese and Minangkabau people, respectively in the cities of Banda Aceh and Meulaboh, did not anticipate the phenomenon and were thus caught by the waves. The different behaviours of the victims have been commanded by the existence or the absence of a disaster subculture among affected communities as well as by their capacity to protect themselves in facing the tsunami. People’s behaviours and the capacity to protect oneself can be further tracked down to a deep tangle of intricate factors which include the armed conflict that has been affecting the province since the 1970s, the historical and cultural heritage and the national political economy system. This paper finally argues that the uneven impact of the 26 December 2004 earthquake and tsunami in Aceh lies in the different daily life conditions of the ethnic groups struck by the disaster.  相似文献   

14.
The northern Nagano Prefecture earthquake, MJMA?6.7 (Mw?6.2), which is inferred to have been triggered by the huge (Mw?9.0) March 11, 2011 Tohoku earthquake, occurred on March 12, 2011, in northern Nagano Prefecture, an area in Japan famous for heavy snowfall. A large number of landslides were triggered by the 12 March earthquake, and it caused building damage in the area of the epicenter. To clarify characteristics of the distribution and dynamic behavior of these landslides, we analyzed aerial photographs and conducted field surveys in and around the epicentral area. Large-scale landslides with long distance run-outs are a remarkable characteristic of the landslides induced by this earthquake. The long travel distance is considered to be related to the thick snowpack at the time the earthquake occurred. Moderate scale deep-seated landslides and shallow landslides were also observed in the study area. Based on an analysis of landslides with the active fault on which the earthquake is believed to have occurred, most of these landslides were distributed on the hanging wall of the active fault, within a distance of 12?km from the fault.  相似文献   

15.
Seismogenesis of aftershocks occurring in the Kachchh seismic zone for more than last 10?years is investigated through modeling of fractal dimensions, b-value, seismic velocities, stress inversion, and Coulomb failure stresses, using aftershock data of the 2001 Bhuj earthquake. Three-dimensional mapping of b-values, fractal dimensions, and seismic velocities clearly delineate an area of high b-, D-, and Vp/Vs ratio values at 15?C35?km depth below the main rupture zone (MRZ) of the 2001 mainshock, which is attributed to higher material heterogeneities in the vicinity of the MRZ or deep fluid enrichment due to the release of aqueous fluid/volatile CO2 from the eclogitisation of the olivine-rich lower crustal rocks. We notice that several aftershocks are occurred near the contacts between high (mafic brittle rocks) and low velocity regions while many of the aftershocks including the 2001 Bhuj mainshock are occurred in the zones of low velocity (low dVp, low dVs and large Vp/Vs) in the 15?C35?km depth range, which are inferred to be the fractured rock matrixes filled with aqueous fluid or volatiles containing CO2. Further support for this model comes from the presence of hydrous eclogitic layer at sub-lithospheric depths (34?C42?km). The depth-wise stress inversions using the P- and T-axes data of the focal mechanisms reveal an increase in heterogeneity (i.e., misfit) with an almost N?CS ??1 orientation up to 30?km depth. Then, the misfit decreases to a minimum value in the 30?C40?km depth range, where a 60o rotation in the ??1 orientation is also noticed that can be explained in terms of the fluid enrichment in that particular layer. The modeling of Coulomb failure stress changes (??CFS) considering three tectonic faults [i.e., NWF, GF, and Allah bund fault (ABF)] and the slip distribution of the 2001 mainshock on NWF could successfully explain the occurrences of moderate size events (during 2006?C2008) in terms of increase in positive ??CFS on GF and ABF. In a nutshell, we propose that the fluid-filled mafic intrusives are acting as stress accentuators below the Kachchh seismic zone, which generate crustal earthquakes while the uninterrupted occurrence of aftershocks is triggered by stress transfer and aqueous fluid or volatile CO2 flow mechanisms. Further, our results on the 3-D crustal seismic velocity structure, focal mechanisms, and b-value mapping will form key inputs for understanding wave propagation and earthquake hazard-related risk associated with the Kachchh basin.  相似文献   

16.
On October 23, 2011, a magnitude of Mw 7.2 earthquake struck the Van province in eastern Turkey which caused approximately 600 life loss and 4,000 injured people. Although the recorded peak ground accelerations were relatively low (0.15–0.2 g) compared with that of other recent destructive Turkish earthquakes and the code-based design response spectrum, a large number of reinforced concrete buildings with 4–6 stories and non-engineered masonry buildings were either heavily damaged or collapsed in the region. Based on the post-earthquake technical inspections, the goal of this paper is to introduce major reasons for structural damages in the disaster area and to discuss these failures along with the approaches given in the design code which is renewed after August 17, 1999 Marmara Earthquake. Some remarkable lessons learned from earthquake-induced failures and damages specific to building construction techniques are presented in this paper.  相似文献   

17.
Two moderate magnitude earthquakes (M5.5 and M5.4) occurred in January 2010 with their epicenters at a distance of about 5?km between them, in the western part of the Corinth Gulf. The recordings of the regional seismological network, which is dense locally, were used for the location of the two main events and aftershocks, which are concentrated in three clusters beneath the northern coasts of the Gulf. The first two clusters accompany each one of the two stronger earthquakes, whereas the third cluster comprises only low magnitude aftershocks, located westward of the two stronger events. Seismic excitation started in January 18, 2010, with the M?=?5.5 earthquake in the area occupied by the central cluster. Seismicity immediately jumped to the east with numerous aftershocks and the M?=?5.4 earthquake which occurred four days later (January 22, 2010). Cross sections normal to the long axis of each cluster show ruptures on north dipping faults at depths of 7?C11?km. Focal mechanisms of the stronger events of the sequence support the results obtained from the spatial distribution of the aftershocks that three different fault segments activated in this excitation. The slip vectors of all the events have an NNW?CSSE to NNE?CSSW orientation almost parallel to the direction of extension along the Corinth Gulf. Calculation of the Coulomb stress changes supports an interaction between the different clusters, with the major activity being coincided with the area of positive induced stress changes after the first earthquake.  相似文献   

18.
On February 22, 2011, an earthquake of magnitude 6.3 occurred very near to the city of Christchurch, New Zealand. The consequence came as a shock to many seismologists and earthquake engineers as New Zealand is known as the homeland of modern earthquake-resistant design techniques. After the earthquake, the focus of discussion has been on the collapse of buildings, while few queried the adequacy of design requirements. Importantly, similar “inadequacy” seems to repeat all around the world more frequently than expected. Hence, the question statement in the title concerns not only Christchurch, but anywhere in the world.  相似文献   

19.
Li  Fan  Wang  Lin  Jin  Zhigang  Huang  Lifang  Xia  Bo 《Natural Hazards》2019,104(1):101-121

Most disaster research has focused on business recovery at a point in time or over a short period of time, with the goal of summarizing the experience to reduce business vulnerability in future disasters. However, studies on long-term business recovery processes may be more useful for providing lessons that support sustained business operations after a disaster. This study considers the changes in business’ operating statuses following the initial survival of a large earthquake and examines how different factors influence sustained business operations during the long-term recovery after a disaster. The study uses logistic regression techniques along with field investigations and questionnaire data collected from 256 New Beichuan businesses that remained open following the 2008 Wenchuan earthquake in China. The study results showed that some of the original surviving businesses closed during the subsequent post-disaster operation process. As such, identifying businesses reopening after the disaster cannot be equated with long-term recovery. Factors significantly influencing the sustained operation of a business after the Wenchuan earthquake included: pre-disaster financial conditions, post-disaster monthly average profit, borrowing of money from family or friends, the business owner’s gender, and government subsidies. Study findings have important theoretical implications for research on the long-term recovery of businesses after an earthquake. Findings also have practical value for business owners selecting post-disaster sustainable operation strategies.

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20.
Natural Hazards - In this study, Dempster–Shafer theory (DST) is integrated into a geographic information system to model vulnerability of the land surface to earthquake events in...  相似文献   

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