European Macroseismic Scale Research Articles

Seismic vulnerability assessment using association rule learning: application to the city of Constantine, Algeria

We performed a seismic vulnerability assessment of the city of Constantine (Algeria) using the Risk-UE and datamining-based methods [association rule learning (ARL)]. The ARL method consists in establishing relationships between building attributes (number of stories or building age) and the vulnerability classes of the European Macro-seismic Scale, EMS98. This approach avoids the costly process of drawing up an inventory of building characteristics in the field, which often discourages the assessment of seismic risk initiatives in weak to moderate seismic-prone regions. We showed that the accuracy of the assessment is independent of the subset used for the learning phase leading to development of the Constantine vulnerability proxy. Considering only two attributes, the vulnerability assignment is equal to about 75%, reaching 99% if material is added to the attributes considered. Comparison of Risk-UE and ARL results revealed a reliable assessment of vulnerability, the differences having only a slight impact on the probability of exceeding the damage level computed by EMS98 or Risk-UE in Constantine. The results of this study suggest that the ARL-based vulnerability proxy is efficient and could be applied to the rest of Algeria.

Analysis of the 2016 Amatrice earthquake macroseismic data

On August 24, 2016, a sudden MW 6.0 seismic event hit Central Italy, causing 298 victims and significant damage to residential buildings and cultural heritage. In the days following the mainshock, a macroseismic survey was conducted by teams of the University of Padova, according to the European Macroseismic Scale (EMS98). In this contribution, a critical analysis of the collected macroseismic data is presented and some comparisons were performed with the recent 2012 Emilia sequence.

The 24 August 2016 Amatrice earthquake: macroseismic survey in the damage area and EMS intensity assessment

<p>The 24 August 2016 earthquake very heavily struck the central sector of the Apennines among the Lazio,Umbria, Marche and Abruzzi regions, devastating the town of Amatrice, the nearby villages and other localities along the Tronto valley. In this paper we present the results of the macroseismic field survey carried out using the European Macroseismic Scale (EMS) to take the heterogeneity of the building stock into account. We focused on the epicentral area, where geological conditions may also have contributed to the severity of damage. On the whole, we investigated 143 localities; the maximum intensity 10 EMS has been estimated for Amatrice, Pescara del Tronto and some villages in between. The severely damaged area (8-9 EMS) covers a strip trending broadly N-S and extending 15 km in length and 5 km in width; minor damage occurred over an area up to 35 km northward from the epicenter.</p>

Thumbnail‐Based Questionnaires for the Rapid and Efficient Collection of Macroseismic Data from Global Earthquakes

The collection of earthquake testimonies (i.e., qualitative descriptions of felt shaking) is essential for macroseismic studies (i.e., studies gathering information on how strongly an earthquake was felt in different places), and when done rapidly and systematically, improves situational awareness and in turn can contribute to efficient emergency response. In this study, we present advances made in the collection of testimonies following earthquakes around the world using a thumbnail‐based questionnaire implemented on the European‐Mediterranean Seismological Centre (EMSC) smartphone app and its website compatible for mobile devices. In both instances, the questionnaire consists of a selection of thumbnails, each representing an intensity level of the European Macroseismic Scale 1998. We find that testimonies are collected faster, and in larger numbers, by way of thumbnail‐based questionnaires than by more traditional online questionnaires. Responses were received from all seismically active regions of our planet, suggesting that thumbnails overcome language barriers. We also observed that the app is not sufficient on its own, because the websites are the main source of testimonies when an earthquake strikes a region for the first time in a while; it is only for subsequent shocks that the app is widely used. Notably though, the speed of the collection of testimonies increases significantly when the app is used. We find that automated EMSC intensities as assigned by user‐specified thumbnails are, on average, well correlated with “Did You Feel It?” (DYFI) responses and with the three independently and manually derived macroseismic datasets, but there is a tendency for EMSC to be biased low with respect to DYFI at moderate and large intensities. We address this by proposing a simple adjustment that will be verified in future earthquakes.

Empirical fragility curves from damage data on RC buildings after the 2009 L’Aquila earthquake

The study analyses the data related to a database of 7597 private Reinforced Concrete buildings located in the city and the province of L’Aquila surveyed after the 2009 earthquake. Survey data were collected by the Italian Department of Civil Protection during post-earthquake usability inspections including information on building characteristics, level and extent of damage to structural and non-structural components. For each building, the Peak Ground Acceleration demand has been determined according to data available from the ShakeMap of the event and the georeferenced building location. The analysis of data highlights the key role played by the damage to non-structural components—namely, infills and partitions. Damage Grades according to the European Macroseismic Scale EMS-98 have been derived from damage data to single building components. Two building classes have been defined in the study in order to investigate the influence of number of storeys of buildings on the observed damage. Damage Probability Matrices have been derived for the assumed building classes and bins of Peak Ground Acceleration, and observed trends are analyzed. Different methodologies for estimating fragility functions from data on Damage Grades and Peak Ground Acceleration demand are illustrated, discussed and applied to the database, leading to the derivation of EMS-98-based fragility curves for the defined building classes. Finally, the proposed fragility curves are compared with main empirical fragility curves for RC buildings from literature studies.

How could cumulative damage affect the macroseismic assessment?

When strong earthquakes occur, buildings are usually affected by multiple, consecutive seismic shakings causing a progression of the damage. This paper presents a comprehensive discussion on how the cumulative damage caused by multiple shocks could influence the assignment of macroseismic intensity. The potential consequences in case of single or multiple shocks are investigated through a large set of simulations, applying a simplified non-linear structural model on a stock of masonry buildings taken from real cases. The results allow an estimation of the changes in vulnerability, with reference to the European Macroseismic Scale classification, for the buildings that suffered a specific damage in a prior shock. Simulations reckon a significant difference in the macroseismic intensity assignments, especially when the same damage is associated to single or multiple seismic shocks. We highlight the potential bias due to the cumulative damage on the correlation between macroseismic intensity and ground motion parameters, and we formulate a proposal for testing on the field, in the case of future earthquakes, what has been here investigated through a simplified simulation.

Using structural damage statistics to derive macroseismic intensity within the Kathmandu valley for the 2015 M7.8 Gorkha, Nepal earthquake

We make and analyze structural damage observations from within the Kathmandu valley following the 2015 M7.8 Gorkha, Nepal earthquake to derive macroseismic intensities at several locations including some located near ground motion recording sites. The macroseismic intensity estimates supplement the limited strong ground motion data in order to characterize the damage statistics. This augmentation allows for direct comparisons between ground motion amplitudes and structural damage characteristics and ultimately produces a more constrained ground shaking hazard map for the Gorkha earthquake. For systematic assessments, we focused on damage to three specific building categories: (a) low/mid-rise reinforced concrete frames with infill brick walls, (b) unreinforced brick masonry bearing walls with reinforced concrete slabs, and (c) unreinforced brick masonry bearing walls with partial timber framing. Evaluating dozens of photos of each construction type, assigning each building in the study sample to a European Macroseismic Scale (EMS)-98 Vulnerability Class based upon its structural characteristics, and then individually assigning an EMS-98 Damage Grade to each building allows a statistically derived estimate of macroseismic intensity for each of nine study areas in and around the Kathmandu valley. This analysis concludes that EMS-98 macroseismic intensities for the study areas from the Gorkha mainshock typically were in the VII–IX range. The intensity assignment process described is more rigorous than the informal approach of assigning intensities based upon anecdotal media or first-person accounts of felt-reports, shaking, and their interpretation of damage. Detailed EMS-98 macroseismic assessments in urban areas are critical for quantifying relations between shaking and damage as well as for calibrating loss estimates. We show that the macroseismic assignments made herein result in fatality estimates consistent with the overall and district-wide reported values.

Comment on “Ground Motions from the 2015Mw 7.8 Gorkha, Nepal, Earthquake Constrained by a Detailed Assessment of Macroseismic Data” by Stacey S. Martin, Susan E. Hough, and Charleen Hung

In their study of the Nepal earthquake of 25 April 2015, Martin et al. (2015) build a large European Macroseismic Scale (EMS‐98) intensity dataset, from which they infer some results in terms of attenuation laws and reconsideration of historical earthquakes. In this article we would like to draw attention to how the EMS‐98 practice, as established in the official guidelines (Grunthal, 1998; see also Musson and Cecic, 2012), was distorted by Martin et al. (2015), so that we wonder why they decided to adopt this tool instead of other macroseismic scales more suitable to interpret the data they collected. The EMS‐98 scale, differently from the Mercalli–Cancani–Sieberg scale (Sieberg, 1930) and the modified Mercalli intensity scale (Wood and Neumann, 1931) is founded on three cornerstones: quantities (observed), building vulnerability, and damage grade. Each one of these three elements must be considered in order to assess a reliable intensity value. This kind of approach, formerly introduced by the Medvedev–Sponheuer–Karnik (MSK) scale (Medvedev et al. , 1965), becomes more accurate with the EMS‐98 that recognizes the statistical nature of intensity (Grunthal, 1998) and makes the assessment of the intensity more rigorous. Martin et al. (2015) do not embrace the accuracy required by the EMS‐98, both in the assessment of intensity degrees and in the interpretation of the diagnostics. In spite of the considerable number of observations based on media and first‐person accounts, the authors assess intensity values without estimating quantities. Quantitative adjectives are rarely used, and when present, they are expressed with words different than “few,” “many,” “most,” as stated by the EMS‐98 guidelines. Similarly, the words “vulnerability” …

Reply to “Comment on ‘Ground Motions from the 2015Mw 7.8 Gorkha, Nepal, Earthquake Constrained by a Detailed Assessment of Macroseismic Data’ by Stacey S. Martin, Susan E. Hough, and Charleen Hung” by Andrea Tertulliani, Laura Graziani, Corrado Castellano, Alessandra Maramai, and Antonio Rossi: Table 1

We thank Andrea Tertulliani and his colleagues for their interest in our article on the 2015 Gorkha earthquake (Martin, Hough, et al. , 2015), and for their comments pertaining to our study (Tertulliani et al. , 2016). Indeed, as they note, a comprehensive assessment of macroseismic effects for an earthquake with far‐reaching effects as that of Gorkha is not only critically important but is also an extremely difficult undertaking. In the absence of a widely known web‐based system, employing a well‐calibrated algorithm with which to collect and systematically assess macroseismic information (e.g., Wald et al. , 1999; Coppola et al. , 2010; Bossu et al. , 2015) in the Indian subcontinent, one is left with two approaches to characterize effects of an event such as the Gorkha earthquake: a comprehensive ground‐based survey such as the one undertaken in India following the 2001 Bhuj earthquake (Pande and Kayal, 2003), or an assessment such as Martin, Hough, et al. (2015) akin to other contemporary studies (e.g., Nuttli, 1973; Sieh, 1978; Meltzner and Wald, 1998; Martin and Szeliga, 2010; Ambraseys and Bilham, 2012; Mahajan et al. , 2012; Gupta et al. , 2013; Singh et al. , 2013; Hough and Martin, 2015; Martin and Hough, 2015; Martin, Bradley, et al. , 2015; Ribeiro et al. , 2015), based primarily upon media reports and other available documentary accounts. Tertulliani et al. (2016) do not propose to undertake a ground‐based survey; this would be not only an undeniably valuable, but also a difficult and protracted exercise. Nor do they suggest a different macroseismic scale that might be more appropriate than the 1998 European Macroseismic Scale (henceforth EMS‐98) used by Martin, Hough, et al. (2015). Martin, Hough, et al. (2015) essentially already follow their recommendation to make the best use of documentary resources, including video recordings, …

Investigation of Damage in and Around Kathmandu Valley Related to the 2015 Gorkha, Nepal Earthquake and Beyond

An earthquake with a magnitude of 7.8 (M w ) occurred at 11:56 NST (local time) on 25 April 2015, in the central part of Nepal (Gorkha).We organized a damage survey team and dispatched it to the affected area for several periods following the earthquake (May 26 to June 3: first trip, June 17 to 24: second trip, August 16 to 21: third trip and October 27 to November 2: forth trip) to investigate the damage and collect data. We found traditional construction methods are stronger than imagined. Many traditional earthquake-resistance technologies exist in Nepal. The first and second surveys were to collect timely statistical information on the damage to brick and stone masonry buildings and to confirm the availability of data and their sources for subsequent surveys. We also carried out a first-hand building damage survey in selected areas. The investigation of the strong-motion data set from the USGS Center for Engineering Strong Motion Data includes information from stations in Nepal that continued to function throughout the main shock and the several subsequent strong aftershocks of the 2015 earthquake. The third and fourth surveys were to collect the every building damage survey in selected areas. The motivation behind the survey was to obtain ground truth data for the calibration and improvement of a wide-area damage estimation system that uses satellite data; the system is currently under development by National Research Institute for Earth Science and Disaster Prevention (NEID) and the Japan Aerospace Exploration Agency (JAXA). A survey of the degree of damage was conducted for every house in Sankhu and Khokana by the European Macroseismic Scale (EMS) -98. This report outlines the findings of this investigation team into various aspects of the earthquake disaster in the Kathmandu Valley. The motivation behind the survey was to obtain ground truth data for the calibration and improvement of a wide-area damage estimation system that uses satellite data. Field surveys confirmed that the severely damaged urban area was well detected by the decrease derived from the ALOS-2 satellite SAR data. The higher classification accuracy for non-damaged area helps to detect the damaged urban area using this technique, immediately after a disaster.

Observed and predicted earthquake damage scenarios: the case study of Pettino (L’Aquila) after the 6th April 2009 event

A damage scenario based on observational data collected in L’Aquila Municipality after the 6th April 2009 earthquake is compared with a predicted damage scenario derived from the application of a simplified analytical method for seismic vulnerability assessment of Reinforced Concrete (RC) buildings at large scale. The observational damage scenario is derived from a database of 131 RC buildings located in the Municipality of L’Aquila, which after the 2009 earthquake were subjected to post-earthquake usability assessment procedure. The simplified analytical approach adopted is based on the Capacity Spectrum Method to evaluate seismic capacity at different Damage States (DSs) based on the displacement capacity of structural and non-structural elements. DSs and the corresponding displacement capacity are defined through the interpretation of the observational-based DSs provided by the European Macroseismic Scale EMS-98. Data predicted by the adopted methodology are in good agreement with the observed damage distribution. The observed damage scenario is also compared with predicted scenarios derived from other methodologies from literature.

ZEMĚTŘESENÍ V HOSTĚRADICÍCH V ČERVNU 2014

Southern Moravia – a southeastern part of the Czech Republic at the contact of the Bohemian Massif and the Carpathian Foredeep – is one of the regions with the lowest seismic activity in the Czech Republic. Reports on historical earthquakes in this area are sporadic and poorly evidenced, many of the messages are in fact observations of earthquakes originating mainly in Austria. Instrumental seismic monitoring in southern Moravia commenced in 1995. Thereafter only three local earthquakes were observed – magnitude 2.5 event near Hostěradice in 2000, perhaps induced event near Uhřice in 2003 with magnitude of 0.7 and magnitude 1.4 earthquake near Božice in 2006.A sequence of four weak earthquakes in June 2014 is only the fourth occurrence of earthquakes in southern Moravia since the beginning of instrumental measurements. Events originated near Hostěradice (SE margin of the Bohemian Massif), 40 km southwest of Brno. The strongest event reaching local magnitude of 2.0 occurred on June 1, 2014 at 00:43 UTC. It was felt by people close to the epicentre with a macroseismic intensity 4 European Macroseismic Scale EMS-98. A temporary seismic station was immediately installed in the epicentral area. The station recorded two of four shocks and helped to confi rm a focus position of the sequence: 48.95° N 16.24° E, depth 3 km.In 2014 a review of historical earthquakes in this region was conducted using new catalogues of historical earthquakes in neighboring countries in order to avoid confusion between local and regional phenomena. Some new information sources were found. In any case, historical earthquakes in this region are very rare and most of them are poorly substantiated.

Selection of Ground Motion Prediction Equations for Seismic Hazard Analysis of Peninsular India

Seismic hazard analysis provides an estimation of seismic hazard parameters like peak ground acceleration (PGA) or spectral acceleration (SA) for different periods. The extent of ground shaking and the hazard values at a particular region are estimated using ground-motion prediction equations (GMPEs)/attenuation equations. There are several GMPEs applicable for the region to estimate the PGA and SA values. These equations may result in higher or lower PGA and SA values than the region specific reported values, which are based on the parameters involved in the development of GMPEs. In this study, an attempt has been made to identify the best GMPEs for various parts of Peninsular India (PI) by performing an “efficacy test,” which make use of the average log likelihood value (LLH). Various intraplate earthquakes such as Coimbatore earthquake, Satpura earthquake, Anjar earthquake, Koyna earthquake, Bhadrachalam earthquake, Broach earthquake, Shimoga earthquake, Killari earthquake, Jabalpur earthquake, Pala earthquake, Kottayam earthquake, and Bhuj earthquake have been considered for the same. Macroseismic intensity maps of these earthquakes have been digitalized and European Macroseismic Scale (EMS) values at the surface have been synthesized. PGA value determined from each GMPE for known magnitude and hypocentral distances are then converted to EMS values. These calculated EMS values have been used to estimate LLH values which are further used to compute Data Support Index (DSI), rank and weights corresponding to a particular GMPE. Conventionally, LLH values are estimated for the entire distance range and GMPEs are ranked accordingly, but in this study, the LLH is calculated for the distance segments of 0-200 km and 200 km to maximum damaged distance in the region based on Isoseismal maps. If the maximum damaged distance is less than 200 km, a distance segment up to 200 km is adopted. Comparison between the rankings of the GMPEs in segments 0–200 km and 200–maximum damage distance is presented here. Segment-based GMPEs ranking shows different ranks, DSI and weights for each GMPE as compared to ranking considering entire distance. Finally, this study provides a list of GMPEs that perform best for the estimation of ground motion parameters in different parts of PI. This study shows that the GMPEs of HAHO-97, ATK-08, CAM-06, TOR-02, NDMA-10, and PEZA-11 perform better for the estimation of ground motion in most part of PI in the distance segment 0–200 km. The GMPEs of TOR-02, RAIY-07, and RAIY-07 (PI) perform best in the 200-maximum damage distance segment.

Ground Motions from the 2015Mw 7.8 Gorkha, Nepal, Earthquake Constrained by a Detailed Assessment of Macroseismic Data

ABSTRACT To augment limited instrumental recordings of the M w 7.8 Gorkha, Nepal, earthquake on 25 April 2015 (Nepali calendar: 12 Baisakh 2072, Bikram Samvat), we collected 3831 detailed media and first-person accounts of macroseismic effects that include sufficiently detailed information to assign intensities. The resulting intensity map reveals the distribution of shaking within and outside of Nepal, with the key result that shaking intensities throughout the near-field region only exceeded intensity 8 on the 1998 European Macroseismic Scale (EMS-98) in rare instances. Within the Kathmandu Valley, intensities were generally 6–7 EMS. This surprising (and fortunate) result can be explained by the nature of the mainshock ground motions, which were dominated by energy at periods significantly longer than the resonant periods of vernacular structures throughout the Kathmandu Valley. Outside of the Kathmandu Valley, intensities were also generally lower than 8 EMS, but the earthquake took a heavy toll on a number of remote villages, where many especially vulnerable masonry houses collapsed catastrophically in 7–8 EMS shaking. We further reconsider intensities from the 1833 earthquake sequence and conclude that it occurred on the same fault segment as the Gorkha earthquake.

Vulnerabilidad y riesgo sísmico de los edificios residenciales estudiados dentro del Plan Especial de evaluación del riesgo sísmico en la Comunidad Valenciana

This paper presents a study about the seismic vulnerability of residential buildings in the Valencian region, as part of the Special Plan for the seismic risk. The regional government has the obligation to develop these type of plans in areas with seismic intensities higher than VII degrees, accord to the European Macroseismic Scale. The methodology used to identify the constructive characteristics in the region, age of buildings, to assign seismic vulnerability classes, to estimate potential damage caused by a probable earthquake and mapping the risk arising, is presented. We highlighted the estimation of an average high damage of 13 % of the number of buildings in the Alicante region, decreasing in Valencia and Castellon to 8 % and 0.2 %, respectively. To manage data a geodatabase has been created, managed by a Geographic Information System, a very effective tool, specially to the immediate response to multicriteria questions.

A Monument for an Earthquake‐Rotated Monument

Research Article| July 15, 2015 A Monument for an Earthquake‐Rotated Monument Klaus‐G. Hinzen; Klaus‐G. Hinzen University of Cologne, Seismological Station Bensberg, Vinzenz‐Pallotti Street 26, 51429 Bergisch Gladbach, Germanyhinzen@uni-koeln.de Search for other works by this author on: GSW Google Scholar Sharon K. Reamer Sharon K. Reamer University of Cologne, Seismological Station Bensberg, Vinzenz‐Pallotti Street 26, 51429 Bergisch Gladbach, Germanyhinzen@uni-koeln.de Search for other works by this author on: GSW Google Scholar Author and Article Information Klaus‐G. Hinzen University of Cologne, Seismological Station Bensberg, Vinzenz‐Pallotti Street 26, 51429 Bergisch Gladbach, Germanyhinzen@uni-koeln.de Sharon K. Reamer University of Cologne, Seismological Station Bensberg, Vinzenz‐Pallotti Street 26, 51429 Bergisch Gladbach, Germanyhinzen@uni-koeln.de Publisher: Seismological Society of America First Online: 14 Jul 2017 Online ISSN: 1938-2057 Print ISSN: 0895-0695 © 2015 by the Seismological Society of America Seismological Research Letters (2015) 86 (5): 1438–1440. https://doi.org/10.1785/0220150114 Article history First Online: 14 Jul 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Klaus‐G. Hinzen, Sharon K. Reamer; A Monument for an Earthquake‐Rotated Monument. Seismological Research Letters 2015;; 86 (5): 1438–1440. doi: https://doi.org/10.1785/0220150114 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietySeismological Research Letters Search Advanced Search During the 2009 L’Aquila earthquake, numerous objects in the mesoseismal zone were rotated (Cucci and Tertulliani, 2011). One prominent earthquake‐rotated object (ERO) is a war memorial in the small town of Paganica, a community that suffered European Macroseismic Scale intensity XIII damage. It is located at 42.3586° N and 13.4713° E, opposite the heavily damaged historical church of Paganica. The location is less than 350 m from the surface rupture of the causative fault of the L’Aquila 2009 earthquake. The war memorial is an unusual ERO because the 14.7° (0.26 rad) counterclockwise‐rotated monument is a simple block with... You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Macroseismic investigations of the geological site effects on intensities of selected earthquakes in greater Ljubljana area

Ljubljana is one of three regions with the highest seismic hazard in Slovenia. In addition soft sediments in the Ljubljana basin have a strong influence on seismic ground motion. We used macroseismic data to investigate the influence of local geological structure on earthquake intensities in greater Ljubljana area. We determined intensities for eleven earthquakes according to ground classification based on Eurocode 8 standard (EC8). The results showed a systematic increase in observed seismic intensities, determined according to European Macroseismic Scale (EMS-98), as the seismogeological characteristics of the ground deteriorated. Only one ground type (D) showed slightly lower intensities than expected. This may be due to some unrevealed geological and other factors, or because of very limited macroseismic data available for this particular ground type.

Development and urban-scale application of a simplified method for seismic fragility assessment of RC buildings

A simplified analytical method for the seismic fragility assessment of Reinforced Concrete buildings at large scale is presented. The proposed method is based on a simulated design procedure to define the structural model and on non-linear static analysis of a simplified structural model based on Shear-Type assumption to evaluate seismic capacity. Damage States are defined according to the observational-based Damage States provided by the European Macroseismic Scale (EMS-98). Presence of infills is considered, both taking into account their influence on the structural response and evaluating the damage to such non-structural elements. The method is applied to the Reinforced Concrete building stock data provided by the field survey carried out on a city in a high seismic area in Southern Italy, which are illustrated and compared with data from other sources. Uncertainties in seismic demand, material characteristics, and capacity models are taken into account through a Monte Carlo simulation technique. Fragility curves are obtained for each building, leading to the evaluation of annual failure probability at the assumed Damage States. The influence of key parameters in predicting seismic fragility, such as the number of storeys and the age of construction, is illustrated. The spatial distribution of annual failure probability at the different Damage States provides information on areas most prone to seismic risk within the city, depending both on building stock characteristics and on local amplification of seismic hazard due to soil conditions. A comparison with empirical-based fragility curves from literature is also illustrated.

Fast and Efficient Evaluation of Building Damage From Very High Resolution Optical Satellite Images

In this paper, we present a novel combination of object features to both match buildings from predisaster images to shapes in a postdisaster image and assess damage on those buildings. These features include scale profile ratios extracted from a tree of shapes representation of the original image as well as texture features. A supervised classifier is used to classify building damage into three representative classes tied to the European Macroseismic Scale (EMS-98). The method is compared to visual inspection results as well as other automated methods. Results clearly show the benefits of our method for fast crisis mapping applications with few human inputs required.

Macroseismic intensity data of the 22 April 2013 Tenk (Hungary) earthquake

On 22 April 2013 an earthquake of magnitude 4.8 occurred near the village of Tenk (Hungary), which was the strongest Hungarian earthquake in the past 28 years. This event was detected by a number of seismological stations, thus it is well documented. Nevertheless, it is still possible to get further data through macroseismic surveys, which cannot be obtained using seismological instruments, but are very useful for the understanding of seismic properties of the affected area. The studied earthquake was felt in approximately third of the territory of Hungary. The number of incoming macroseismic questionnaires was over eight hundred and damage descriptions for the epicentral area reached almost one thousand. Intensity evaluation was carried out following the European Macroseismic Scale guidelines. Intensities were assigned to 211 places, including 23 districts of Budapest. The earthquake caused non-structural building damages, the epicentral intensity was estimated as VI on the EMS-98 scale and was assigned to three villages: Tenk, Átány and Erdőtelek. The event was widely felt west to the epicentre, but much less observed in the east direction. The asymmetry of the intensity distribution raises questions and requires further investigation.