J. Woessner, L. Danciu, D. Giardini, H. Crowley, F. Cotton, G. Grünthal, G. Valensise, R. Arvidsson, R. Basili, M. Betül Demircioglu, S. Hiemer, Carlo Meletti, R. W. Musson, A.N. Rovida, K, Sesetyan, M. Stucchi
The Global Hazard Mosaic coverage of the Euro-Mediterranean region uses the Seismic Hazard Harmonization in Europe (SHARE) Project model: an EU-funded project coordinated by the Swiss Federal Institute of Technology in Zurich, Switzerland (Giardini et al., 2013; Woessner et al., 2015). The model was originally implemented in the OpenQuake (OQ) engine. Hazard for the Kaliningrad Region of Russia was also computed using this model. Athough SHARE covers Turkey, the more recent EMME model was used here.
Information about the OQ model versions and input files can be found on the Results and Dissemination page.
The viewer below depicts the seismic sources and hazard results in terms of PGA for a return period of 475 years. Click on the menu in the upper right corner to select the layer.
Seismic and tectonic activity in Europe is concentrated in the south, relating to the plate boundaries in the Mediterranean region. Convergence between Africa and Europe has produced a wide reverse fault and subduction zone complex stretching from the Rif-Betic Cordillera in southern Iberia and northern Morocco, east through the Algerian and Tunisian continental slopes and then through the southern Italian region (where subduction of microplates is quite complicated) and then through the Hellenic subduction zone south of the Aegean Islands. North and west of the Aegean, the North Anatolian Fault forms a strike-slip plate boundary with the Anatolian Plate and distributed faulting in the southern Balkan Peninsula. The Italian Peninsula is also faulted throughout, with active extension along normal faults cutting through the high Apennines and reverse faults in the Adriatic Sea. Farther north, some slow strain and seismicity are present throughout the Alpine chain from Spain through the Balkans. Additional very slow faulting extends through northern Europe in zones such as the Rhine Graben. In the Carpathians, the subducted slab from a previous episode of plate convergence still produces moderate to large magnitude earthquakes as the slab deforms and sinks into the mantle; fortunately, these earthquakes may be quite deep and less damaging than if they were in the European crust.
Please see Giardini et al., 2013 and Woessner et al., 2015.
Seismic Source Characterisation
The input model includes a combination of OpenQuake source typologies that represent seismological, geological, tectonic, and geodetic information. Shallow crustal sources (depth < 40 km) are modelled by three unevenly weighted logic tree branches that use different data and approaches, but have equal spatial coverage. Subduction and deep seismicity is modeled separately by a single branch. The source models are:
- Crustal branch 1: area sources that fully cover the region and have parameters defined by tectonic regionalisation
- Crustal branch 2: point sources representing smoothed seismicity, which considers both catologue occurrences and active faults
- Crustal branch 3: simple fault sources to reflect characterised faults, with area sources accounting for background seimsicity
- Subduction: complex fault sources that represent the subduction interface, and area sources to model intraslab seismicity and the deep earthquakes in the Vrancea region
Epistemic uncertainty is accounted for by using the three-branch logic tree, and - in earlier modeling steps - by varying the approach used to define the source parameters.
Ground Motion Characterisation
|Active Shallow Crust||Weight|
|Stable Shallow Crust||Weight|
Hazard curves were computed with the OQ engine for peak ground acceleration (PGA) and spectral acceleration (SA) at 0.2s, 0.5s, 1.0s, and 2s. The computation was performed on a grid of 99146 sites (spaced at approximately 10 km) with reference site conditions with shear wave velocity in the upper 30 meters (Vs30) of 760-800 m/s.
The hazard map for PGA corresponding to a 10% probability of exceedance in 50 years (475 year return period), can be seen using the interactive viewer. For a more comprehensive set of hazard and risk results, please see the GEM Visualization Tools.
Giardini, D., J. Woessner, L. Danciu, H. Crowley, F. Cotton, G. Grünthal, R. Pinho et al. "Seismic hazard harmonization in Europe (SHARE): online data resource." Swiss Seism. Serv ETH Zurich Zurich Switz. Doi 10 (2013).
Woessner, Jochen, Danciu Laurentiu, Domenico Giardini, Helen Crowley, Fabrice Cotton, Gottfried Grünthal, Gianluca Valensise et al. "The 2013 European seismic hazard model: key components and results." Bulletin of Earthquake Engineering 13, no. 12 (2015): 3553-3596.