Investigation of Paleo and Active Landslides in the Trabzon/Degirmendere Valley Using Ground Shear Strain

The topographic structure, land slope, rainfall amount, and proximity to the North Anatolian Fault Zone (NAFZ) and offshore faults (Trabzon, Ordu, and Rize Faults) in the Eastern Black Sea Region contribute to the frequent occurrence of landslides in this area. The Black Sea Region has the highest number of landslide-related casualties in Türkiye. In this study, an area with both paleo and active landslides, located 10 km from the city center of Trabzon, was selected as the study area. The use of the Ground Shear Strain (GSS) parameter in landslide-prone areas is demonstrated. During the study, the Horizontal to Vertical Spectral Ratio (HVSR) and Standard Spectral Ratio (SSR) methods were applied to calculate the ground predominant period and soil amplification. The Multi-Channel Analysis of Surface Waves (MASW) and Rayleigh Wave Ellipticity (RWE) methods were used to determine shear wave velocity. The results indicate that in landslide-prone areas with low shear wave velocity, the ground predominant period can increase up to 1.3 seconds, and the GSS value can rise to 0.5. The clear increase in GSS values in landslide-prone areas shows the reliability of this parameter in landslide investigation. © 2025 NSG. All Rights Reserved.