Ground motion and aftershock seismicity characteristics following the Mw 6.5 earthquake in Paphos, Cyprus on January 11, 2022

Abstract

On January 11, 2022, a powerful 6.5 magnitude earthquake struck Paphos, Cyprus, affecting the broader eastern Mediterranean area, including Türkiye, Syria, Lebanon, and Egypt. Recorded seismic activity revealed a peak ground acceleration (PGA) and a peak ground velocity (PGV) indicating intense shaking and rapid motion. Ground motion parameters, including intensity, perceived shaking, potential damage, PGA, PGV, and instrumental intensity, were used to evaluate the earthquake's impact. Over nearly two years following the event, comprehensive data collection recorded 693 seismic events with an estimated completeness magnitude (Mc) of 1.4. Analysis using the maximum likelihood method demonstrated a b-value of 0.65 ± 0.09, suggesting the mainshock occurred in a zone of elevated tectonic stress, potentially increasing the likelihood of larger. The aftershock decay rate, with a p-value of 0.73, indicates a quick reduction in stress levels post-mainshock, accompanied by a high frequency of initial aftershocks as shown by a c-value of 5.0. Moreover, a k-value of 10.0 suggests that aftershock activity began declining approximately ten days after the main event. The application of the correlation integral technique yielded a fractal dimension (Dc) of 1.75 ± 0.01, indicating aftershock clustering along a particular fault line. The analysis also exhibited a slip ratio of 0.58, indicating significant slip during the mainshock, with potential implications for future stress distribution. Integrating these findings with geological studies provides deeper insights into fault dynamics, stress distribution, and future seismic activity forecasting.