Rupture Status of the Southeastern Fault Segment of the June 20, 1990 (Mw 7.4) Rudbar Earthquake

Abstract

In this study, we investigate the spatial distribution of landslides, strong motion data, and seismic intensity patterns associated with the June 20, 1990, earthquake, with a moment magnitude (Mw) of 7.4. Our primary objective is to elucidate the rupture status of the southeastern segment, Zard Geli, of the coseismic rupture by integrating geological and seismological data, Our findings indicate that the southeastern segment experienced only a partial rupture during the 1990 earthquake. This partial rupture is evidenced by the disproportionate distribution and density of landslides along the surface rupture. The incomplete rupture of this segment suggests that it retains a considerable amount of accumulated strain energy that was not fully released during the 1990 event. Consequently, this segment remains a potential source for future seismic activity. These findings have implications for seismic hazard assessment and risk mitigation in the region. This study highlights the need for continued monitoring and detailed geological and seismological investigations to better anticipate and mitigate the effects of future earthquakes.