The historical catalogue compiled so far includes more than 2,000 records for the time period 2000 BC to 1899. Approximately 25% of the records do not include intensity or magnitude estimates. The instrumental catalogue covering the time period from 1900 to 2010 includes 6,102 records with Mw >=5, 526 of them with Mw >= 6, 134 with Mw >= 6.5 and 41 with Mw >= 7.
In order to get here, the following activities were carried out:
- The coverage of the catalogue was checked all over the EMME region.The existence of local seismicity data / historical earthquake data for all sub-regions was certified.
- The range of depths for different regions as well as seismic sources were investigated
- The range of uncertainties for Mmax for different regions was checked. The magnitude discrepancies were also checked with the international catalogues.
- The border regions were checked to match the seismicity parameters and Mmax for sub-regions located in the border areas.
- ompleteness periods for different magnitude ranges were determined
- The catalogue is being declustered
Instrumental Earthquake Catalogue
A digital active tectonic map of the Middle East region has been generated. A total of 3,397 active fault sections are defined and faults with a total length of 91,551 km have been parameterized. Additionally, the digital active fault map of Afghanistan, which was prepared by USGS (Ruleman et al., 2007) was added to the active fault map. A database of fault parameters is compiled for active faults that are capable of generating earthquakes above a threshold magnitude Mw >= 5.5. This database includes information on the geometry and rates of movement of faults in a “Fault Section Database” following a revised and extended version of the WGCEP-2007 format and information on the timing and amounts of fault displacement in a separate “PaleoSites Database”.
The databases and information compiled in the form of fault geometry and seismicity and the associated parameters such as fault rupture characteristics, earthquake epicenter, depth, magnitude and mechanisms culminate in a final seismic source zonation model, where individual source zones are characterized in terms of maximum magnitude that the source zone is able to produce, the magnitude recurrence model and associated parameters, rupture mechanism and depth distribution. The source zonation model with 200 areal sources was reviewed by the various project partners to obtain a consensus model based on individual country models that are combined and homogenized at the border regions. The source zones are characterized by tectonic regionalization, maximum magnitude (based on both historical seismicity and fault length), pre-dominant rupture mechanism, depth distribution and earthquake recurrence parameters, all parameters being assigned based on the earthquake catalogue and fault section databases compiled for the project region.
The analytical testing methods proposed by Scherbaum et al. (2009) and Kale and Akkar (2012) were used in ranking the candidate GMPEs and to select the final set for the logic-tree application of SACRs in EMME territory. The following multi-step approach was carried out while ranking the 14 candidate ground-motion equations:
- Use entire dataset and compute LLH and EDR indices for spectral periods of T = 0.0s, 0.1s, 0.2s, 0.5s, 0.75s, 1.0s, 1.5s and 2.0s.
- Rerun LLH and EDR using the subsets of the ground-motion dataset assembled according the specific features of each predictive model
- Subdivide the ground-motion dataset for different magnitude and distance bins and rerun the LLH and EDR once again to compute the corresponding indices.
Both LLH and EDR methods yielded very similar results in this multi-stage testing approach and the testing of each GMPE was evaluated from EDR and LLH indices computed after every step. The overall performances of Akkar and Bommer (2010), Zhao et al. (2006), Akkar and Cagnan (2010) and Chiou and Youngs (2008) were relatively better than the rest of the candidate GMPEs.
Seismic Risk Assessment
Work on exposure is one of the most critical elements for risk assessment in the region and a building inventory and population distribution database has almost been completed. A grid based distribution has been compiled in a GIS environment by the majority of the partners at a country scale and were subsequently homogenized. In addition to and building on the GEM Building Taxonomy a regional taxonomy has been developed. In addition, partners have also proposed intensity based vulnerability parameters for the proposed building classification for loss estimation calculations in regional scale.
Population distribution for Iran
Six city scenarios are being developed following calls for propsals. Masshhad (Iran), Gulshen-Karachi (Pakistan), Yerevan (Armenia), Tbilisi (Georgia), Irbid (Jordan) and Tyr (Lebanon). The activities form a unique opportunity to match the needs of policy makers with those of experts, and all interactions have so far been a great success.
For each city data has been compiled in terms of building inventory, population distribution, soil conditions and other input data for loss estimation. In addition vulnerability parameters have been developed for use in loss estimation calculations at urban scale. The activities within the city scenario applications are carried out in collaboration with local institutes and municipality officials, which makes each of the projects unique and a learning school for future city-based risk assessment anywhere in the world.
The students that carried out building surveys in the summer of 2011
- A city scenario workshop was conducted on July 18, 2011 where the project team and stakeholders discussed the goals and progress, making sure that needs were met
The study area was identified to include the City of Irbid and the city of Aidoun, with a total of 265,586 inhabitants and 25,684 building according to the 2004 census (covering 46.36 km2)
A shear wave map (Vs30) was prepared using the Multichannel Analysis of Surface waves (MASW) technique
115 profiles were conducted and interpreted
Working on the shear wave map
- Buildings inventories were developed
- Building Vulnerability models were proposed based on Givionazzi and Lagomarsino (2004).
- Probabilistic seismic hazard maps were prepared for 475 and 2475 year of return periods, based on Campbell & Bozorgnia (2008-NGA)
- MASW was used to prepare a final soil classification map
- An inventory of residential buildings was compiled on a 250 x 250 m grid cell
- Building classification based on EMS-98 typology
- Population distribution was compiled at the district scale
- Intensity based vulnerability functions are used for each building type