Exploiting earthquake-induced landslide inventories for macroseismic assessment using the Environmental Seismic Intensity (ESI-07) scale

Eliana Muccignato ^* Maria Francesca Ferrario

• Department of Science and High Technology, University of Insubria, Como, Italy

Earthquake-induced landslides are one of the most impacting effects triggered by seismic events and represent a relevant risk factor. Inventories of earthquake-induced landslides are available for many case histories and may contain thousands of elements. The spatial pattern of landslides is typically analyzed in terms of density and areal coverage (LND: Landslide Number Density; LAP: Landslide Area Percentage). In addition to landslides, other earthquake environmental effects, such as surface faulting, liquefaction, or tsunami, may be triggered. A comprehensive evaluation of earthquake environmental damage can be achieved using the Environmental Seismic Intensity (ESI-07) scale; however, landslide inventories have not yet been fully exploited in terms of ESI-07 assessment. Here, we apply a grid-based methodology to compute LND, LAP and ESI-07 values for 40 landslide inventories related to 33 earthquakes worldwide. We derive the first empirical equations relating ESI-07 to LND or LAP, demonstrating that the LAP metric is more robust. We also find that the inventory itself (i.e., how landslide polygons are delineated) introduces much higher uncertainty into the process compared to the selection of a specific area-volume conversion equation. A comparison with independent ESI-07 data shows that the proposed procedure is reliable. We claim that our approach can be applied in other contexts and could represent the basis for enhanced collaboration between the scientific communities working on landslides and seismic intensity assessment.The authors declare they have no competing interests. The landslide inventories used in this study can be accessed from the USGS page An Open Repository of Earthquake-Triggered Ground-Failure Inventories -ScienceBase-Catalog (last access January 2024) or from the cited literature.EM's PhD is funded by the European Union -NextGenerationEU -Mission 4 "Education and Research" -Component 2 "From Research to Business" -Investment 3.1 "Fund for the realization of an integrated system of research and innovation infrastructures" -Project IR0000037 -GeoSciences IR. We wish to thank all the scientific community who had applied the ESI-07 scale to earthquakes worldwide. The ESI-07 isoseismals for the Palu earthquake were produced by Elena Sioli during her Bachelor thesis at Insubria University.