Disasters have a vital impact on people's lives in many aspects. History has shown that earthquakes are one of the deadliest of all the catastrophes that can be triggered by nature, such as thunderstorms, landslides, or droughts. During the 20^th century, earthquakes accounted for more than 200,000 deaths and over 250 billion Euros in direct and indirect losses in Europe (EM-DAT). 

Millions of earthquakes hit Europe every year, though most are too small to be felt or to cause damage. However, severe events occur periodically. Each time such a strong earthquake affects a region in Europe, it reminds us of the impact it can have: bricks fall from roofs, façades crack, walls collapse, debris damages parked cars, and citizens get injured or even lose their lives. Up to now, earthquakes cannot be precisely predicted, but effective risk mitigation measures derived from earthquake hazard and risk models can significantly reduce their impacts.

Model is a frequently used term that you may encounter in many different fields. Usually, models enable calculations to be undertaken to determine how something might develop in reality.

Examples can be the financial losses due to a strong earthquake at a given place or the level of ground shaking due to earthquakes at different locations. Earthquake hazard and risk models provide such estimates and thus set the basis of any mitigation measure aiming to reduce the potential impacts of earthquakes. In Europe, many countries regularly conduct and publish regional or national earthquake hazard assessments, and a few of them even undertake earthquake risk assessments. Such models, when available, provide authoritative information to inform national, regional and local decisions related to developing seismic design codes and risk mitigation strategies. 

However, underlying datasets of national earthquake hazard and risk models are not constructed consistently and often vary in their compilations. For defining transnational disaster mitigation strategies that support the definition of insurance policies or up-to-date building codes, harmonised earthquake hazard and risk models covering a broader territory are needed. Further, they provide a basis upon which national authorities can further build.

Up-to-date European earthquake hazard and risk models are particularly important to compare the levels of threat between countries and to support the definition of transnational risk mitigation strategies. Compiling harmonised datasets for models covering nearly the entire European territory is challenging, given the complex tectonic environment and the diverse seismogenic potential of Europe. Furthermore, underlying datasets are often not constructed consistently due to country-specific approaches, or they are not publicly available.

Having been developed with a harmonised approach, the 2020 European Seismic Hazard and Risk Models provide comparable information to civil protection agencies, politicians, civil engineers, architects, insurances, communities, and many others about areas most likely to be affected by damaging earthquakes and about the concentration of vulnerable structures. Therefore, the models allow transnational hazard and risk comparisons. Since they are harmonised in contrast to country-specific approaches, they allow to recognize differences due to actual seismotectonic diversity, as well as construction differences within the built environment more clearly. 

National or regional earthquake hazard and risk models, when available, give authoritative information to inform national, regional, and local decisions related to developing seismic design codes and risk mitigation strategies. Europe’s earthquake hazard and risk models, however, provide a basis upon which national authorities can further build. In any case, users of the European earthquake hazard and risk models should always consult the national regulations before applying these European models in practice. Note that earthquake hazard values must always first be translated into standards for earthquake-resistant design and cannot be used directly as a basis for construction.

Locations and frequencies of earthquakes, and their effects on humans and the built environment, cannot be reliably predicted. Related uncertainties are, therefore, an inherent part of the models. Acknowledging and quantifying these uncertainties is at the core of the model building process and is necessary to establish reliable models.

The likelihood and impact of earthquake-induced environmental (so-called secondary) effects, such as landslides, liquefaction, rock falls, or tsunamis, can be assessed by adding further datasets and models on top of these European earthquake hazard and risk models. Thanks to the current models, we better understand how often and how intensely the earth could shake in the future at a given location. This is an essential input for further research and analyses related to these secondary hazards.

The earthquake hazard model does not include induced earthquakes that are caused by human activity (such as geothermal operations, reservoir impoundment, wastewater injections, or oil and gas operations). Nevertheless, components of the hazard and risk model (such as the building and population exposure model) can still be used by modelers to assess the impact of induced seismicity. 

The development of Europe’s earthquake hazard and risk models have been an effort that started more than 30 years ago and has involved thousands of people from all over Europe. These efforts have been funded by several European projects and supported by national groups over all these years.

One of the first earthquake hazard models for Europe was published in 2002. In 2015, the Euro-Mediterranean Seismic Hazard Model (ESHM13) became public. It was developed within the SHARE project (Woessner et al., 2015). Four years later, the Horizon 2020 SERA Project started with two work packages (JRA3 and JRA4) focusing on updating the earthquake hazard model for Europe and developing the first open-access earthquake risk model for Europe of its kind. The SERA project ended in May 2020, but efforts to finalise the models have been continued within the EU-funded projects RISE and EPOS-IP. 

The European Facilities for Earthquake Hazard and Risk (EFEHR) maintains and will further develop the earthquake hazard and risk model for Europe in collaboration with the GEM Foundation and the European Plate Observing System (EPOS). EFEHR is a non-profit network of organisations and community resources aiming to advance assessments of earthquake hazard and risk in the European-Mediterranean area.

EFEHR closely collaborates with the Global Earthquake Model (GEM) Foundation. GEM plans to update the European component of its Global Seismic Risk model using the results of these European models. Furthermore, the earthquake hazard and risk models for Europe will be collaboratively updated and improved together with GEM in the coming years. The services associated with these models are integrated within the EPOS (European Plate Observing System) research infrastructure. They will continue to be made available through the EPOS ICS-C data access portal.