What is seismic risk?

Seismic hazard is calculated based on the frequency and strength of earthquakes affecting a given geographical area, in other words its seismicity.

It is defined as the likelihood that an earthquake will occur — in a given area and within a given window of time — with a strength or magnitude exceeding a given threshold. This likelihood is determined by experts by studying the strength and frequency of earthquakes that have occurred in the past in a given geographical area.

The term “seismic risk”, on the other hand, refers to the estimated damage resulting from an earthquake that could occur. The parameters factored in are as follows: the area’s hazard rating, the likelihood of an earthquake having negative effects in that given area; exposure, the likelihood of people and/or buildings being damaged in the event of an earthquake; and vulnerability, the assessment of building strength, and of the efficiency of a region’s emergency services.

Seismic risk, determined by the combination of these parameters, hence indicates the severity of the damage expected within a given window of time, based on the type of seismicity, strength of buildings and to what extent the natural environment has been transformed to meet human needs (nature, quality and quantity of exposed property).

An area that has a high seismic hazard rating but is not home to human activity will have a low seismic risk. Whereas an area that has a low seismic hazard rating but is densely populated will have a very high seismic risk since even a moderate earthquake could have serious consequences.

The “key” parameter that demands the utmost attention is the vulnerability of buildings. Its value depends on the type of building and level of maintenance: this is the main factor to focus on to reduce the earthquake risk in each region.

Italy has a medium-to-high seismic hazard rating (based on seismic event frequency and strength), very high vulnerability (given the fragility of our residential, commercial and industrial building stock, and infrastructure) and extremely high exposure (given our population density and our unique historical, artistic and monumental heritage found nowhere else in the world). This puts Italy at high seismic risk, which is why we need to keep coming up with new forms of prevention, maintenance and ways to bring buildings up to code to keep people and property safe.

With our country’s inherent fragility in mind, Seriana S.p.A. is invested daily in finding the best solutions to ensure companies’ workplaces are always made safe.