Uplifted marine terraces by active coastal tectonic deformation along the east of Algiers: implications for African and European plate convergence and sea-level curves

Abstract

Marine terraces are geological features composed of elevated, flat surfaces and steep slopes. The evolution of these terraces is largely influenced by active coastal tectonic deformation. This study investigates the uplift of marine terraces along the east coast of Algiers and its implications for the African and European plate convergence and sea-level curves. The objective of studying marine terraces in the Zemmouri area is to gain a deeper understanding of the evolution of the Earth's coastlines and how they have been shaped over time by natural processes such as sea level changes, tectonic activity, geomorphic parameters, and erosion. Marine terraces provide valuable information about the history of sea level changes and the rate of tectonic uplift or subsidence of the coastal areas. Secondary data sources, including qualitative information and high-resolution satellite imagery (SRTM 30 m and ALOS 12.5 m), were used to analyze the impact of sea level on marine terraces. Fieldwork using GPS and altimeter measurements at the site of the Mw=6.8 Zemmouri earthquake that occurred on May 21, 2003, revealed the presence of two well-preserved marine terraces, which serve as important markers for measuring the long-term fault slip rate. The analysis highlights the significance of active coastal tectonic deformation in shaping the coastlines. This research offers new insights into the ongoing processes of plate convergence and sea level change along the east coast of Algiers, contributing to our overall comprehension of coastal evolution and the potential for seismic hazards in the region.