Seminar : Arnaud Montabert

Quantitative archaeoseismology: towards a characterisation of the seismic movement associated with a historical earthquake

In seismic zones, stresses accumulate along fault planes. Beyond a certain limit, the fault ruptures and releases some of the energy in the form of vibrations. This is the earthquake. The life of a fault is thus characterised by the repetition over time, for varying lengths of time, of a stress accumulation phase, followed by a rupture phase. This repetition, or return period, varies greatly depending on the tectonic context and is difficult to predict. Ten years, a century, a thousand years - how can we characterise an ancient earthquake with instrumental data that has only been available for a few decades?

Over the last few decades, a number of alternative approaches have been developed. Historians, archaeologists, seismologists and geologists are trying to use other sources of information. Among them, historic buildings, like "stone seismometers", can be used to bear witness to past seismicity, which they have recorded in their walls in the form of damage or repairs. Civil engineering plays a key role. Over the last few years, I have been working to develop an innovative methodology linking construction archaeology (Montabert, 2020), seismology and earthquake engineering (Montabert, 2023) in order to demonstrate that the archaeological characterisation of post-seismic repairs to historic buildings can be used to deduce the main characteristics of seismic movement.
In this presentation, I will provide an overview of the case studies that contributed to the creation of this methodology. In particular, we will see that the role of characterising and modelling historic structures lies at the heart of quantitative archaeoseismology, and more broadly in the preservation of built heritage.

Montabert A., Dessales H., Arrighetti A., Clément J., Lancieri M. & Lyon-Caen H., Tracing the seismic history of Sant’Agata del Mugello (Italy, Tuscany) through a cross-disciplinary approach, Journal of Archaeological Science: Reports, 33 (2020) 102440, doi, 10.1016/j.jasrep.2020.102440.

Montabert A., Mercerat E. D., Lyon-Caen H. & Lancieri M., Highlighting the impact of the construction history of a Cultural Heritage building through a vibra;ltion-based Finite Element model updated by Particle Swarm Algorithm, International Journal of Architectural Heritage (2023), doi,10.1080/15583058.2023.2219237.