The Gargano Promontory in southern Italy has drawn the interest of seismologists because of its unusual earthquake activity. The area experiences many small earthquakes, some occurring deep in the Earth's crust. In 2013, a new local seismic network called OTRIONS (OT) was installed to better monitor the region. It includes 15 seismometers and was developed through a partnership between the University of Bari Aldo Moro and the National Institute of Geophysics and Volcanology (INGV).

At first, the network had some problems due to technical issues. These were fixed in 2019, and now the seismic data are available in real time. To improve and update the existing earthquake catalog, researchers re-analyzed 10 years of data using an automatic software tool called CASP. It identified more than 6,900 possible seismic events. After manual checks, about 60% were confirmed as real earthquakes; the rest were quarry blasts or inaccurate detections.

Manual review also helped improve the accuracy of earthquake locations. Two updated earthquake catalogs were created and are shared with this study. The analysis showed the catalog includes very small events. This work confirms the importance of local networks in studying seismic hazards and understanding Earth processes.