Analysis and Forecasting of Romanian Seismicity (AFROS) Project: Aim and Preliminary Results

Introduction. Romania is a country of moderate to high seismicity, known especially for its intermediate-depth seismicity that poses an increased risk on an extended area of Romania, including the capital, Bucharest (e.g., Radulian et al., 2000). Other regions have also experienced shallow seismic activity with significant local impact, for example the recent activity close to Galati city (Poiata et al., 2016; Besutiu et al., 2019). Aim. The AFROS project started in February 2021 and aims to build a comprehensive analysis and forecasting system for Romanian's seismicity, based on state-of-the-art models that are currently in use in seismic countries like US, Japan, Italy and Greece. Methods. We are planning to use advanced statistical and machine-learning tools to quantify the space-time features of Romanian seismicity, as well as other geophysical signals, which can be used for earthquake forecasts, in a probabilistic framework. Seminars and training lectures are organized as part of the project activities. Researchers in the fields of Seismology and Natural Hazards will be invited to participate with forecasting models for Romania. Currently we are performing preliminary catalog analysis to get insight about the reliability of the seismic catalog. Preliminary Results. We have done an analysis of the magnitude of completeness (Mc) for the seismic catalog of Romania and found that it changes as a function of both time and space. In general, the earthquakes of magnitudes above 2.5 are well recorded and complete for the last ten years of recordings, in particular for the Vrancea region. However, for earlier periods, Mc is in general above 3.0. Some contamination of very shallow seismicity with quarry blasts is present and currently some methods are considered to address this issue. Discussion. Building a reliable earthquake dataset before applying various analysis and forecasting algorithms is essential. At the AGU meeting, we will present our preliminary findings and also some other basic characteristics of seismicity, like clustering in space and time and frequency-magnitude distribution of earthquakes. Acknowledgement. This research is supported by the Executive Agency for Higher Education, Research, Development and Innovation Funding (UEFISCDI), Romania, Project AFROS (PN-III-P4-ID-PCE-2020-1361).