Fifteen Years Later: What Have We Learnt From L’Aquila?
A Stark Reminder of Resilience
Emel Seyhan
Jochen Woessner
Laura BarksbyApril 08, 2024
In the early hours of April 6, 2009, the Mw6.3 L’Aquila earthquake struck at the heart of Italy’s Abruzzo region, just 60 miles (100 kilometers) northeast of Rome.
The event was the largest in a sequence of earthquakes, which as is typical for this region, this sequence lasted several months with heightened seismicity rates.
Despite the earthquake being of a relatively moderate magnitude, it is a poignant event not only in the collective consciousness of the people directly affected in the region but across Italian society as a whole.
L’Aquila is one of the most devastating seismic events to impact Italy since 1980. It killed 309 people, injured thousands, and made more than 60,000 people homeless; the population of the city of L’Aquila before the event was around 72,000.
The event occurred in the central Apennines, a mountain range extending from the Gulf of Taranto in the south of Italy to the southern boundary of the Po river basin in the north.
The earthquake resulted from normal faulting on the northwest-southeast-trending Paganica Fault and the extensional tectonic forces associated with the opening of the Tyrrhenian Basin to the west.
Figure 1: (Left) 2009 M6.3 L’Aquila earthquake Modified Mercalli Intensity (MMI) Map by U.S. Geological Survey; (Right) L’Aquila earthquake and Paganica fault (Bertelli et al. 2018)
Damage to both buildings and infrastructure was profound. The medieval city of L’Aquila, renowned for its architectural beauty and historical significance featured a substantial concentration of historic buildings at its center.
But all this was left in ruins as many historical structures were either destroyed or severely damaged, including the iconic San Bernardino Basilica (1454–72; 1527 facade).
More recent construction in L’Aquila, including the new, presumably earthquake-proof wing of L’Aquila Hospital, suffered substantial damage in the event, leading to its closure.
Figure 2: (Left to Right) San Bernardino in L'Aquila: the facade at present; the reconstruction of the facade with a reinforced concrete structure after removing the stone facing (1960); the belfry collapsed in 2009; the extrados of the dome after consolidation with FRP (2011). Images featured in a study from Bartolomucci, C. 2013.Figure 3: Abandoned L’Aquila Hospital
Rebuilding the City and Community
The reconstruction of L'Aquila over the last 15 years has been a slow and complex process, both troubled with challenges but marked by significant achievements.
The aim of the rebuilding efforts is not only to restore what was lost but to improve upon it, incorporating modern earthquake-resistant technologies and designs to safeguard against future seismic events.
This process has also been an opportunity for urban renewal and the preservation of cultural heritage, balancing the need for safety with the desire to maintain the city's historical character.
“An earthquake first of all is very difficult psychologically. It’s difficult physically … on top of that you’ve lost the places where you’ve grown up, you’ve lost the people you’ve grown up with. It takes a very heavy toll on you.”
Quote from a L’Aquila resident.
On this fifteenth anniversary, we not only commemorate the tragic loss of life and the suffering of those affected but also the resilience of the Italian community.
The L'Aquila earthquake serves as a stark reminder of our vulnerability to natural disasters and the importance of preparedness and community solidarity.
Events such as this highlight the ongoing need for investment in disaster risk reduction, including earthquake-resistant construction, early warning systems, public education on emergency response, and of course, the role of the (re)insurance industry and capital markets in risk management.
L’Aquila: Influence on Science, Engineering and Beyond
Earthquakes are low-probability, high-consequence disasters – deemed ‘tail risk’ events. Once they occur, their impact can last for a lifetime, and even in a moderate event like L’Aquila, they can cause a disproportionate amount of damage.
At the time of the event in 2009, its economic loss was estimated to have exceeded US$2.5 billion; the insured loss was a fraction of this at around US$500 million. This event highlighted the relatively low earthquake insurance penetration in Italy, particularly for residential lines, compared to other types of insurance.
There have been numerous initiatives in Italy in recent years to promote earthquake insurance coverage through pools, compulsory schemes, and financial incentives.
These approaches, combined with the low penetration, have bolstered the opportunity for the (re)insurance and capital markets to grow in Italy, supporting expanding insurance coverage, with the two largest Italian insurers, Assicurazioni Generali and Unipol both benefiting from earthquake cover provided through catastrophe bond placements.
Looking at the event from a scientific perspective, the L’Aquila earthquake was influential in many ways:
The event provided significant information and the motivation required to update the Italian national seismic hazard assessment (MPS19, Meletti et al., 2019).
Italy subsequently introduced micro zonation studies into law to characterize in detail the local soil conditions overlaying bedrock. To carry out these studies, the Guidelines for Seismic Microzonation (ICMS 2008) incorporated the latest findings from the earthquake together with the most updated international scientific findings. (Vessia et al. 2020).
Ground motion prediction models for Italy were re-calibrated using the strong motion recordings from 2009.
Fragility functions were updated using data from tens of thousands of residential buildings in L’Aquila.
The earthquake’s influence also extended beyond the scientific realm, affecting public and government policies as well as strategies for reducing disaster risk. An OECD study in 2010 concluded that the Italian emergency response was sound and the system has areas of excellence (OECD, 2010).
Brighter Future Prospects
Italy is historically prone to high seismic activity, and additionally, a significant portion of Italy's building infrastructure is susceptible to seismic activity. However, the penetration rate is notably lower in residential areas as compared to commercial and industrial areas.
As we look back to 2009, we look forward to a future where the lessons learned from L'Aquila and other disasters inform a more resilient and prepared society. The memory of the earthquake and its aftermath urges us to continue working towards safer, more sustainable communities, where the risk of such devastation is minimized, and the capacity to recover and rebuild is strengthened.
Marking the fifteenth anniversary of this tragic event, we must reflect on the impact it had, the lessons learned, and the steps taken towards recovery and resilience.
At Moody’s, we are in the process of analyzing Italy’s complex seismic and engineering landscape as we rebuild Moody’s RMS Europe Earthquake Model with a comprehensive update to all model components.
The update will be informed by a recalibrated and extended earthquake catalog, enhanced databases and parameterization of causative crustal faults, strong motion recordings, site measurements, damage data, and historical seismic events like the 2009 L’Aquila earthquake, the 2012 Emilia-Romagna sequence, and others.
By integrating and expanding the latest scientific insights from national and European-wide seismic hazard and risk research (e.g. Meletti et al., 2019, Danciu et al., 2024), the upcoming Moody’s model will employ a comprehensive approach to enhance our risk management strategies and help reshape the earthquake insurance risk landscape.
To learn more about the update to our Europe Earthquake Model, please contact your Moody’s RMS account manager.
If you are joining us at the Exceedance 2024 conference in Montreal (May 6-9), we will have a dedicated track session entitled “Plans for the New Europe Earthquake HD Models” looking at our work on the Europe Earthquake Model update and its conversion to HD (high-definition) modeling.
In this Exceedance session, you can learn about our update plans for the different components and specific considerations for the transition to the HD framework.
Find out more about these sessions at Exceedance here.
References:
Meletti, C., Marzocchi, W., D’Amico, V., Lanzano, G., Luzi, L., Martinelli, F., Pace, B., Rovida, A., Taroni, M., Visini, F. and Group, M. W. (2021) “The new Italian seismic hazard model (MPS19)”, Annals of Geophysics, 64(1), p. SE112. doi: 10.4401/ag-8579.
Danciu, L., Giardini, D., Weatherill, G., Basili, R., Nandan, S., Rovida, A., Beauval, C., Bard, P.-Y., Pagani, M., Reyes, C. G., Sesetyan, K., Vilanova, S., Cotton, F., and Wiemer, S.: The 2020 European Seismic Hazard Model: Overview and Results, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2023-3062, 2024.
Those were the words of the then Italian Prime Minister, Matteo Renzi, in the aftermath of two earthquakes on the same day, October 26, 2016. As a statement of indomitable defiance at a scene of devastation it suited the political and public mood well. But the simple fact is there is work to do, because Italy is not as strong as it could be in its resilience to earthquakes.
There’s a long history of powerful seismic activity in the central Apennines: only recently we’ve seen L’Aquila (2009, Mw6.3), Amatrice (August 2016, Mw6.0), two earthquakes in the area near Visso (October 2016, Mw 5.4 and 5.9) and Norcia (October 2016, Mw6.5). These have resulted in hundreds of fatalities, mainly attributed to widespread collapse of old buildings, emphasizing that earthquakes don’t kill people – buildings do. Whilst Italy’s Civil Protection Department provides emergency management and support after earthquakes, there is too little insurance help for the financial resiliency of the communities most affected by all these events. While the oft-repeated call for earthquake insurance to be compulsory continues to be politically unobtainable, one way it could be spread more widely is through effective modeling. And RMS expertise can help with this, allowing the market to better understand the risk and so build resilience.
Examining High Building Fragility
The two most significant factors for earthquake risk in Italy are (i) construction materials and (ii) the age of the buildings. The majority of the damaged and destroyed buildings were made from unreinforced masonry, and built prior to the introduction of the most recent seismic design and building codes, making them particularly susceptible. With the RMS® Europe Earthquake model capturing both the variations in construction types and age, as well as other vulnerability factors, (re)insurers can accurately reflect the response of different structures to earthquakes. This allows the models to be used to evaluate the cost benefits of retrofitting buildings. RMS has worked with the Italian National Institute for Geophysics and Volcanology (INGV) to see how such analyses could be used to optimize the allocation of public funds for strengthening older buildings, thereby reducing future damage and costs.
Seismic Risk Assessment
The high-risk zone of the central Apennines is described well by probabilistic seismic hazard assessment (PSHA) maps, which show the highest risks in that region resulting from the movement of tectonic blocks that produce the extensional, ‘normal’ faulting observed. The maps also show earthquake risk throughout the rest of Italy. RMS worked with researchers from INGV to develop our view of risk in 2007, based on the latest available databases at that time, including active faults and earthquake catalogs. The resulting hazard model produces a countrywide view of seismic hazard that has not been outdated by newer studies, such as the 2009 INGV Seismic Hazard Map and the 2013 European Seismic Hazard Map published by the SHARE consortium, as shown below:
The Route to Increased Resiliency
Increasing earthquake resiliency in Italy should also involve further development of the private insurance market. The seismic risk in Italy is relatively high for western Europe, whilst the insurance penetration is low, even outside the central Apennines. For example, in 2012, there were two large earthquakes in the Emilia-Romagna region of the Po valley, where there are higher concentrations of industrial and commercial risks. Although the type of faults and risks vary by region, such as the potential impact of liquefaction, the RMS model captures such variations in risk and can be used for the development of risk-based pricing and products for the expansion of the insurance market throughout the country.
Whilst Italy’s seismic events in October caused casualties on a lesser scale than might have been, the extent of the damage highlights once again the prevalence of earthquake risk. It is only a matter of time before the next disaster strikes, either in the Central Apennines or elsewhere. When that happens, the same questions will be asked about how Italy could be made more resilient. But if, by then, the country’s building stock is being made less susceptible and the private insurance market is growing markedly, then Italy will be able to say, with justification, it is becoming stronger than any earthquake.
Emel leads global ground motion modeling and site effects including nonlinear site amplification and sedimentary basin modeling for Moody's RMS earthquake projects. She joined Moody's RMS after her postdoctoral studies at the Pacific Earthquake Engineering Research Center (PEER) at the University of California, Berkeley.
Among her many accomplishments, Emel has completed many Moody's RMS projects and published ten peer-reviewed journal papers between 2013-2020, some of which were ranked among the most cited publications. Worldwide, her published models have been used as reference models by scientists, academics, and practicing engineers including USGS, Global Earthquake Model (GEM), and Geoscience Australia. She is most well known for her NGA-West 2 models.
Emel continues to consult and play an active role in national and international engineering and seismic hazard projects. Emel holds a Ph.D. and a master's degree in Civil Engineering (Geotechnical) from the University of California, Los Angeles.
Jochen is a lead modeler in the earthquake model development team at Moody's RMS and is based in Zurich.
Since joining Moody's RMS in 2014 after 15 years in academia, he has focused on transferring latest earth science to earthquake risk models in the Asia Pacific region.
Laura Barksby
Assistant Director - Product Manager, Moody's RMS
Laura joined Moody's RMS in 2014 and is an Assistant Director - Product Manager within the global earthquake product management team, based in London. She is responsible for the Moody's RMS New Zealand Earthquake HD Model, as well as the Australia earthquake, and Europe earthquake models.
Laura is a Certified Catastrophe Risk Analyst and holds a bachelor’s degree in Geography, and a master’s degree in Risk and Environmental Hazard both from Durham University.
