11 research outputs found
The 2014 Earthquake Model of the Middle East: seismogenic sources
The Earthquake Model of Middle East (EMME) project was carried out between 2010 and 2014 to provide a harmonized seismic hazard assessment without country border limitations. The result covers eleven countries: Afghanistan, Armenia, Azerbaijan, Cyprus, Georgia, Iran, Jordan, Lebanon, Pakistan, Syria and Turkey, which span one of the seismically most active regions on Earth in response to complex interactions between four major tectonic plates i.e. Africa, Arabia, India and Eurasia. Destructive earthquakes with great loss of life and property are frequent within this region, as exemplified by the recent events of Izmit (Turkey, 1999), Bam (Iran, 2003), Kashmir (Pakistan, 2005), Van (Turkey, 2011), and Hindu Kush (Afghanistan, 2015). We summarize multidisciplinary data (seismicity, geology, and tectonics) compiled and used to characterize the spatial and temporal distribution of earthquakes over the investigated region. We describe the development process of the model including the delineation of seismogenic sources and the description of methods and parameters of earthquake recurrence models, all representing the current state of knowledge and practice in seismic hazard assessment. The resulting seismogenic source model includes seismic sources defined by geological evidence and active tectonic findings correlated with measured seismicity patterns. A total of 234 area sources fully cross-border-harmonized are combined with 778 seismically active faults along with background-smoothed seismicity. Recorded seismicity (both historical and instrumental) provides the input to estimate rates of earthquakes for area sources and background seismicity while geologic slip-rates are used to characterize fault-specific earthquake recurrences. Ultimately, alternative models of intrinsic uncertainties of data, procedures and models are considered when used for calculation of the seismic hazard. At variance to previous models of the EMME region, we provide a homogeneous seismic source model representing a consistent basis for the next generation of seismic hazard models within the region.Published3465-34966T. Studi di pericolosità sismica e da maremotoJCR Journa
Evaluation of The Seismic Hazard in The Marmara Region (Turkey) Based on Updated Databases
The increase in the wealth of information on the seismotectonic structure of the Marmara region after two devastating earthquakes (M7.6 Izmit and M7.2 Duzce events) in the year 1999 opened the way for the reassessment of the probabilistic seismic hazard in the light of new datasets. In this connection, the most recent findings and outputs of different national and international projects concerning seismicity and fault characterization in terms of geometric and kinematic properties are exploited in the present study to build an updated seismic hazard model. A revised fault segmentation model, alternative earthquake rupture models under a Poisson and renewal assumptions, as well as recently derived global and regional ground motion prediction equations (GMPEs) are put together in the present model to assess the seismic hazard in the region. Probabilistic seismic hazard assessment (PSHA) is conducted based on characteristic earthquake modelling for the fault segments capable of producing large earthquakes and smoothed seismicity modelling for the background smaller magnitude earthquake activity. The time-independent and time-dependent seismic hazard results in terms of spatial distributions of three ground-shaking intensity measures (peak ground acceleration, PGA, and 0.2 s and 1.0 s spectral accelerations (SA) on rock having 10% and 2% probabilities of exceedance in 50 years) as well as the corresponding hazard curves for selected cities are shown and compared with previous studies
Çizgisel ve Mekansal Düzleştirilmiş Sismik Kaynak Model Kullanılarak Türkiye Olasılıksal Deprem Tehlike Analizi
Türkiye ve çevresindeki yoğun sismik aktivite, güncel levha hareketleri etkisi altında gelişmiş
çok sayıda levha içi aktif faylar, transform fay sistemleri ve dalma-batma kuşağı gibi ana
tektonik yapılar tarafından kontrol edilmektedir. Bölgedeki deprem tehlikesi daha önce birçok
çalışmada farklı yöntemlerle ele alınmıştır. Ancak, deprem tehlike hesaplamalarına ilişkin son
yıllarda geliştirilen yeni yaklaşımlar ile hesaplamalarda kullanılan temel parametrelerinden
ulusal dirifay veri tabanı ve aletsel deprem kataloğunun yenilenmesi, beraberinde Türkiye
deprem haritalarının da güncellenmesi ihtiyacını ortaya çıkarmıştır. Bu kapsamda, Ulusal
Deprem Stratejisi ve Eylem Planı gereği, ulusal katılımlı proje grubunca, Türkiye Deprem
Tehlike Haritaları yeniden değerlendirilmiştir. Olasılıksal deprem tehlike analizleri i-) alansal
kaynak model ve ii-) çizgisel ve mekânsal olarak düzleştirilmiş sismik kaynak modelleri için
ayrı ayrı ele alınmıştır. Bu çalışmada çizgisel ve mekânsal olarak düzleştirilmiş sismik kaynak
modelin parametrelerinden ve modelden elde edilen sonuçlar değerlendirilmiştir. Söz konusu
modellerde çizgisel sismik kaynaklar boyunca, düzlem konumları da dikkate alınarak 15-km
genişliğinde kuşaklar oluşturulmuştur. Bu kuşaklar içerisinde kalan 6.0’dan büyük
depremlerin doğrudan çizgisel sismik kaynak tarafından üretildiği, dışında kalan depremlerin
ise mekânsal olarak düzleştirilmiş sismisiteden geldiği kabulü yapılarak deprem aktivitesi
hesaplanmıştır. Mekansal düzleştirilmiş sismisite deprem kataloğunun derinlik bilgisine göre
sığ ve derin olarak iki ayrı kategoriye ayrılması ve her bir kategori için tamamlılık
analizlerinin yapılmasıyla hesaplanmıştır. Sonuç olarak, 50 yılda sırasıyla %50, %10 ve %2
aşılma olasılıklarına karşılık gelen 72, 475, 2475 yıllık tekarlanma aralıklarına ilişkin yer
hareketi (maksimum yer ivmesi, 0.2 sn ve 1.0 sn’deki spektral ivme) dağılımları elde edilmiştir
Anahtar Kelimeler: Deprem Tehlikesi ve SenaryolarıThe high seismic activity around Turkey is controlled by the main tectonic structures
containing the active shallow crustal faults, transformed fault systems and subduction fault
systems under the effect of the current plate movement. The regional hazard has been worked
in a several studies with different method. Recently , new techniques used in the last years
about the seismic hazard assessment has brought the necessity to review the national active
fault database and compiled earthquake catalogue with turkey's hazard maps. In this concept
the national earthquake strategy and plan f action are reassessed by national participation
project group. The two seismic sources are modelled separately in the probabilistic
earthquake hazard analysis: 1-Area source model 2- Fault and spatial smoothing seismic source model. In thıs study, we will further focus on definition and delineation of the Fault and
spatial smoothing seismic source model and intrinsic uncertainty on the earthquake
occurrence rates estimation. Based on the surface projection along this faut model, the buffer
zone with 15km are generated. The earthquakes with magnitude greater than 6.0 are assumed
to occur inside this 15 km buffer zone, the rest of the seismicty are assumed to obtain from the
smoothed seismicty, and the earthquake activity are calculated according to this assumption.
The depth knowledge in the seismicty database are also considering into two categories:
Shallow and Deep. The completeness analysis are also computed for each of them. Finally,
PSHA results obtained for the fault and spatial smoothed seismic source model wll be
presented for 72, 475 and 2475 years return periods (corresponding to 50%, 10%, and 2%
probability of exceedance in 50 years) according to PGA, spectral acceleration at 0.2 sec. and
1.0 sec
Development of earthquake lossmap for Europe
For almost real-time estimation of the losses after a major earthquake in the Euro-Mediterranean region, the Joint Research Area-3 (JRA-3) component of the European Union (EU) Project "Network of Research Infrastructures for European Seismology -NERIES'' foresees (at several levels of sophistication)
The 2013 European Seismic Hazard Model: key components and results
The 2013 European Seismic Hazard Model (ESHM13) results from a community-based probabilistic seismic hazard assessment supported by the EU-FP7 project “Seismic Hazard Harmonization in Europe” (SHARE, 2009–2013). The ESHM13 is a consistent seismic hazard model for Europe and Turkey which overcomes the limitation of national borders and includes a through quantification of the uncertainties. It is the first completed regional effort contributing to the “Global Earthquake Model” initiative. It might serve as a reference model for various applications, from earthquake preparedness to earthquake risk mitigation strategies, including the update of the European seismic regulations for building design (Eurocode 8), and thus it is useful for future safety assessment and improvement of private and public buildings. Although its results constitute a reference for Europe, they do not replace the existing national design regulations that are in place for seismic design and construction of buildings. The ESHM13 represents a significant improvement compared to previous efforts as it is based on (1) the compilation of updated and harmonised versions of the databases required for probabilistic seismic hazard assessment, (2) the adoption of standard procedures and robust methods, especially for expert elicitation and consensus building among hundreds of European experts, (3) the multi-disciplinary input from all branches of earthquake science and engineering, (4) the direct involvement of the CEN/TC250/SC8 committee in defining output specifications relevant for Eurocode 8 and (5) the accounting for epistemic uncertainties of model components and hazard results. Furthermore, enormous effort was devoted to transparently document and ensure open availability of all data, results and methods through the European Facility for Earthquake Hazard and Risk (www.efehr.org).ISSN:1570-761XISSN:1573-145
Evolution of seismic hazard maps in Turkey
A review on the historical evolution of seismic hazard maps in Turkey is followed by summarizing the important aspects of the updated national probabilistic seismic hazard maps. Comparisons with the predecessor probabilistic seismic hazard maps as well as the implications on the national design codes conclude the paper
The 2014 seismic hazard model of the Middle East: overview and results
The Earthquake Model of Middle East (EMME) Project aimed to develop regional scale seismic hazard and risk models uniformly throughout a region extending from the Eastern Mediterranean in the west to the Himalayas in the east and from the Gulf of Oman in the south to the Greater Caucasus in the North; a region which has been continuously devastated by large earthquakes throughout the history. The 2014 Seismic Hazard Model of Middle East (EMME-SHM14) was developed with the contribution of several institutions from ten countries. The present paper summarizes the efforts towards building a homogeneous seismic hazard model of the region and highlights some of the main results of this model. An important aim of the project was to transparently communicate the data and methods used and to obtain reproducible results. By doing so, the use of the model and results will be accessible by a wide community, further support the mitigation of seismic risks in the region and facilitate future improvements to the seismic hazard model. To this end all data, results and methods used are made available through the web-portal of the European Facilities for Earthquake Hazard and Risk (www.efehr.org)