What is the 2013 Euro-Mediterranean Seismic Hazard Model (ESHM13)?

Updated

ESHM13 is the 2013 Euro-Mediterranean Seismic Hazard Model produced by the SHARE project, a Collaborative Project under the Seventh Framework Programme of the European Commission. It is a community-based probabilistic seismic hazard assessment (PSHA) covering the Euro-Mediterranean region, and it remains the reference output of SHARE, which ended in 2013. If you need harmonized, cross-border seismic hazard values for Europe and the Mediterranean rather than single-country maps, ESHM13 is the dataset to look at.

What ESHM13 contains

The model consists of more than sixty time-independent ground motion hazard maps. Key parameters:

Parameter Coverage
Spectral ordinates PGA to 4 seconds
Annual exceedance probability 10⁻¹ to 10⁻⁴
Reference rock velocity vs30 = 800 m/s
Minimum magnitude included MW ≥ 4.5

The hazard values are referenced to a rock velocity of vs30 = 800 m/s, so any site-specific use requires adjusting for local soil conditions.

How the model is built

ESHM13 combines three representations of seismicity:

  • Area sources — earthquakes modeled as zones rather than individual faults.
  • Active faults — where fault geometry and behavior are known well enough to model directly.
  • Smoothed background seismicity — a gridded representation that captures activity outside defined sources.

All events with MW ≥ 4.5 are included in the hazard computation.

A distinctive feature is its weighting scheme: input datasets are weighted according to their time horizon. Geologic knowledge is emphasized for products with longer time horizons, while seismological data carries more weight for shorter ones. This is why the model is described as integrating geology, seismology, and earthquake engineering rather than relying on a single discipline.

Why it matters

Before ESHM13, seismic hazard assessments in Europe were largely national efforts with differing methods and assumptions, which made results hard to compare across borders. SHARE built a framework for integration across national borders, compiled earthquake and fault data, and assembled the model through extensive expert elicitation and multiple community feedback procedures. The result is a single authoritative, community-based hazard model for the whole Euro-Mediterranean region, with update mechanisms intended to keep it current.

Citing and accessing the model

If you use ESHM13 in research or reports, cite it as follows:

  • SHARE project: Giardini, D., Woessner J., Danciu L. (2014) Mapping Europe's Seismic Hazard. EOS, 95(29): 261–262.
  • ESHM13 models and results: Woessner, J., Danciu L., D. Giardini and the SHARE consortium (2015), The 2013 European Seismic Hazard Model: key components and results, Bull. Earthq. Eng., doi:10.1007/s10518-015-9795-1.

Outreach materials, including the official poster and brochures, are available through the EFEHR documentation pages for specific hazard models covering Europe.

Practical notes

  • ESHM13 is a regional model. It gives harmonized hazard values across the Euro-Mediterranean area, not site-specific design values.
  • The maps are time-independent, meaning they do not account for the elapsed time since the last earthquake on a given fault.
  • Because values are referenced to vs30 = 800 m/s, using them for a specific site means applying your own site response adjustment.
  • The project ended in 2013, so ESHM13 reflects the data and methods available up to that point; check for later updates if you need the most recent model.