AdriaArray in Albania: Collaborative Deployment, Station Characterization, and Data Integration

Abstract

This study assesses the deployment, integration, and initial performance of broadband seismic stations in Albania under the AdriaArray initiative. As part of the German Seismological Broadband Array (DSEBRA) project, nine stations were installed to enhance seismic monitoring, improve event detection, and refine data quality. Their integration into the Albanian Seismological Network allows for a systematic evaluation of site effects, noise characteristics, and travel time residuals. Horizontal‑to‑vertical spectral ratio analysis reveals strong site‑dependent variability, with soft‑soil sites (e.g., AL07A, AL08A) exhibiting high amplification (A0 > 4.0) and low fundamental frequencies (f0 < 1.0 Hz), while bedrock stations (e.g., AL06A, KKS) show higher fundamental frequencies (f0 > 10 Hz) and reduced amplification (A0 < 2.5). Probabilistic Power Spectral Density analysis highlights seasonal noise fluctuations, with wintertime increases at urban and coastal sites and persistent low‑frequency noise exceeding‑120 dB at certain locations. Travel‑time residuals confirm that bedrock stations (e.g., AL01A, AL03A, AL05A) provide stable phase arrivals, while urban sites show greater scatter, particularly for smaller magnitude earthquakes. The densified network enhances waveform resolution and improves seismic event location accuracy, directly contributing to real‑time moment tensor solutions. The DSEBRA’s stations accounted for 187 of 289 analyzed moment tensor events, with AL05A and AL08A yielding the highest number of high‑quality solutions. These results reinforce the role of uniform instrumentation and regional collaboration in advancing seismic monitoring. The findings establish key benchmarks for the operational quality of AdriaArray stations in Albania, emphasizing the need for further site characterization, noise mitigation at urban sites, and refined velocity models. Continued regional cooperation remains essential for improving earthquake monitoring and geodynamic research in the Adria microplate region.