MAE AFTERSHOCK

The ultimate goal of the project “Analysis of seismic sequences for strong aftershock forecasting”, funded by a grant from the Italian Ministry of Foreign Affairs and International Cooperation, is to develop a practical technique that helps us justify, during ongoing of an aftershock sequence following a damaging earthquake, the likelihood of the occurrence of another strong earthquake (SLE) with a similar magnitude to that of the mainshock.

Many strong earthquakes are followed by a subsequent large earthquake (SLE), of magnitude similar to the initial quake or even stronger. Repeating earthquakes cause accumulated damage on already weakened buildings and infrastructures; therefore, forecasting their occurrence is a challenging task from viewpoint of the civil protection to stop the continuous loss of lives.

The project is the result of collaboration between OGS, INGV and the Japanese “The Institute of Statistical Mathematics (ISM), Research Organization of information and Systems”. It is in the List of Selected Projects of “Particular Relevance” to be considered for founding in the period 2021-2023 within the framework of the Agreement between the Government of Italy and the Government of Japan on Cooperation in Science and Technology, Executive Programme for the years 2021-2023. Signed in Tokyo on the 15th January 2021.

The funds allocation is annual. The project has been founded for 2021: and for 2022 € 30 000 from Italian Ministry of Foreign Affairs and International Cooperation + € 30 000 co-funding by OGS and INGV, we are awaiting confirmation for 2023.

The bilateral collaboration will enable to put together

1. skills in the pattern recognition techniques applied to seismology developed by the Italian staff (NESTORE algorithm) (OGS and INGV);
2. new techniques for forecasting probability distribution of a strong aftershock ETAS-based (ISM and INGV) and for aftershock migration analysis (OGS).

A case study analysis by a technique to detect lower magnitude earthquakes (OGS) developed during a past Italy-Japan collaboration will enhance the quality of results of this project and value past collaborations.

The Project is led by OGS and ISM.

Results:

• Internal repository of papers useful for the project (state of the art on Italian catalogues evaluation, state on the art on subsequent earthquake forecasting, etc.)
• Quantitative comparison between the catalogs available at national and local/regional scale, in terms of completeness and homogeneity of magnitude estimation.
• Application to clusters containing SLEs the new ETAS-based techniques for short-term forecasting of their probability distribution.
• Improvements of NESTORE and first tests onapplication to Italian catalog.
• Reorganization, validation and further development of software related to the NESTORE algorithm to distribute it to the scientific community as free software and make it easily usable even by non-expert users.
• Application of template matching techniques to increase the number of occurrences of a cluster that occurred in Molise in 2018, which has anomalies for both NESTORE and cluster identification.
• Application of the ETAS model for identifying relative quiescences in Molise clusters.
• Application of new cluster identification techniques
• Analysis of seismicity migration using fractal techniques and PCA on enriched clusters.
• Organization of the international workshopworkshops "Seismicity anomalies measured by statistical models" (SAMSM).) on 2021 and 2022.

Publications:

• Gentili, S.,  Brondi, P.,  Rossi,  G., Venturini, E.,  Di Giovambattista, R. (2021). The Italy-Japan project - Analysis of seismic sequences for strong aftershock forecasting Relazioni OGS 2021/94 Sez. CRS 21.
• Lombardi A.M., Falcone G., Murru M., Di Giovanbattista R.(2021) Project: “Analysis of seismic sequences for strong aftershock forecasting”. The ISIDe earthquake catalog. INGV report.
• Falcone, G., Murru, M., Console, R., Spassiani,  I., and  Taroni, M. (2021) Project: "Analysis of seismic sequences for strong aftershock forecasting" Task 3.1 Apply to clusters containing SLEs the new ETAS-based techniques for short-term forecasting of their probability distribution.  INGV report.
• Gentili, S., Di Giovambattista R. (2022). Forecasting strong subsequent earthquakes in California clusters by machine learning. Physics of the Earth and Planetary Interiors, 327, https://doi.org/10.1016/j.pepi.2022.106879.
• Gentili, S., Brondi, P., and Di Giovambattista, R. NESTOREv1.0: A MATLAB package for strong following earthquake forecasting. Accepted by Seismological Research Letters, in press.
• Calderoni, G., Di Giovambattista, R., Ventura, G. A reliable procedure to estimate the rupture propagation directions from source directivity: the 2016-2018 Central Italy seismic sequence. Submitted to Seismological Research Letters.
• Brondi, P., Gentili, S., Di Giovambattista, R. Forecasting strong subsequent events in the Italian territory: a national and regional application for NESTOREv1.0. in preparation.
• Gentili, S., Brondi, P., Campanella, S.,  Di Giovambattista, R., Rossi, G., Sugan, M., Zhuang, J. Analysis of clustering structures in the 2018 Molise earthquake sequence, in preparation.
• Zhuang, J, Gentili, S. Di Giovambattista, R. et al Analysis of seismic sequences for strong aftershock forecasting in preparation.

Congresses and workshops:

• Brondi, P., Gentili, S., and Di Giovambattista, R., 2022. NESTORE applied to Italy and Northeastern Italy. International workshop SAMSM, Udine, October 11, 2022.
• Brondi, P., Gentili, S., and Di Giovambattista, R., 2022. NESTOREv1.0 application to Italian seismicity. 40 GNGTS, 27 - 29 June 2022, Trieste, Italy.
• Gentili, S., 2022. Molise 2018 how many clusters? International workshop SAMSM, Udine, October 11, 2022.
• Gentili, S., Brondi, P., and Di Giovambattista, R., 2022. NESTORE v1.0: A MATLAB based code to forecast strong aftershocks applied to Italian seismicity. 10th Spanish-Portuguese Assembly of Geodesy and Geophysics Toledo (Spain) November 28-December 1, 2022.
• Gentili, S., Brondi, P., and Di Giovambattista, R., 2022. The machine learning-based algorithm NESTORE for strong aftershocks forecasting in seismic clusters becomes a free available software: application to Italy. Book of abstracts 12th International Conference on Statistical Seismology (STATSEI 12), Cargèse, 17th to 21st of October 2022.
• Gentili, S., Brondi, P., and Di Giovambattista, R., 2022. An optimized online version of NESTORE software package for the forecasting of strong aftershocks: an application to Italian clusters, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3959, https://doi.org/10.5194/egusphere-egu22-3959 .
• Gentili, S., Brondi, P., and Di Giovambattista, R., 2022. NESTOREv1.0: a machine learning-based Matlab package for forecasting strong aftershocks in seismic clusters. 40 GNGTS, 27 - 29 June 2022, Trieste, Italy.
• Rossi, G., 2022. Fractal and PCA analysis of the Molise 2018 seismicity. International workshop SAMSM, Udine, October 11, 2022.
• Sugan, M., Vuan, A., and Campanella, S. 2022. Template matching applied to the 2018 Molise seismic sequence. International workshop SAMSM, Udine, October 11, 2022.
• Zhuang, J. and Gentili, S., 2022. Seismic quiescence during NESTORE cluster analyzed using the ETAS model. International workshop SAMSM, Udine, October 11, 2022.
• Gentili, S.,  Di Giovambattista, R. (2021). A pattern recognition approach for strong following earthquake forecasting Spatial Data Science 2020 Rescheduled online June 8-11, 2021. Book of abstracts, page 15.
• Gentili, S.,  Di Giovambattista, R. (2021). Decision tree-based machine learning approach for following strong earthquake forecasting in seismic clusters, 39 GNGTS, online, June 22-24, 2021.
• Gentili, S. and Di Giovambattista, R. (2021). NESTORE: A machine learning approach to strong following earthquake forecasting, 37 General Assembly of European Seismological commission ESC 2021, online, 19-24 September 2021.
• Brondi, P., and Gentili, S. (2021). Quantitative comparison between the catalogs available in northeastern Italy. Clusters of seismicity in Italy and northeastern Italy by window based method. International workshop SAMSM online, December 15, 2021.
• Rossi, G. (2021) Fractal based methods for cluster identification: three case-studies. International workshop SAMSM online, December 15, 2021.
• Murru, M., Console, R., Falcone, G., Spassiani, I., and Taroni, M. (2021). Cluster characterization based on ETAS. International workshop SAMSM online, December 15, 2021.
• Zhuang, J., Ziyao, X., and Falcone, G. (2021). Long-term earthquake forecasting for the Italy region by using the short-term ETAS model. International workshop SAMSM online, December 15, 2021.
• Gentili, S.,  Di Giovambattista, R., and Brondi, P. (2021) Improvements of NESTORE machine learning approach to strong following earthquake forecasting International workshop SAMSM online, December 15, 2021.

Italian staff: Stefania Gentili (coordinator), Giuliana Rossi, Monica Sugan, Alessandro Vuan, Rita Di Giovambattista, Giuseppe Falcone, Anna Maria Lombardi, Maura Murru. Unstructured staff: P. Brondi, Elisa Venturini. Rodolfo Console, Ilaria Spassiani and Matteo Taroni also contributed to the project.

Japanese staff: Jiancang Zhuang (coordinator) , Shun'ichi Nomura, Yoshihiko Ogata, Xiong Ziyao, Takao Kumazawa, Giuseppe Petrillo, Si Zheng Ya.