KLAJDI QOSHI, DAMIANO KOXHAJ, IRENA DUSHI
KEYWORDS : local magnitude scale, earthquake processing, seismic monitoring, regression analysis, Albanian National Earthquake Monitoring Centre.
Abstract :
This study investigates the normalization of the local magnitude (ML) scale utilized in routine local and regional earthquake processing by the Albanian National Earthquake Monitoring Centre. A dataset comprising 406 events from the national database of earthquakes in the Institute of Geosciences (IGEO) spanning 2 years (2021-2022) is analyzed. Events with magnitudes in the range 2.0 ≤ ML ≤ 4.3 are considered, primarily focusing on moderate earthquakes prevalent in the region. Event depths range from 0.5 km to 64.3 km, reflecting the shallow activity associated with the seismically active crust and continental subduction. Regression analysis is conducted to compare ML values reported by TIR with those from the Euro-Mediterranean Seismological Centre (EMSC) and the National Observatory of Athens (NOA), representative seismological agencies for the region. This analysis builds upon previous work covering events from 2021 to 2022, yielding parametric relations. The study utilizes the local model implemented in SEISAN for ML computation. The analysis extends over a longer period, focusing specifically on moderate earthquakes and incorporating a more concentrated spatial extension. Orthogonal regression methodology is employed, accounting for variations in the analyzed variables. The findings contribute to the normalization of the ML scale for local and regional earthquake processing, enhancing the accuracy of seismic magnitude determination and reporting. This work provides valuable insights for seismic monitoring and hazard assessment efforts, particularly related with an representative and homogenize regional earthquake catalogue.