Highlighted Active Tectonics Markers Along Fault-Propagation-Folds in the Tell Atlas (Algeria), Using High-Resolution Pleiades Images

High-resolution satellite Pleiades images produce accurate Digital Elevation Models for precise geomorphological and geological observations. DEMs of 1 m resolution are generated using the PCI Geomatica program to calculate morphometric parameters in relation to active tectonics. The valuable products help identify and characterize tectonic structures in earthquake-prone areas for a better seismic hazard assessment. The Tell Atlas of Northern Algeria was the site of large and destructive earthquakes due to a transpressive tectonic regime and convergence along the western Mediterranean’s Africa–Eurasia plate boundary. Here, we use a panchromatic and multispectral tri-stereo “Pleiades” acquired by ISIS-CNES from 1A and 1B optical satellites. They operate in a true constellation and orbit at 180° to each other. Our data covers large areas with 04 fault-related folds associated with past earthquakes (1922 Tenes Mw 6.2; 1980 El Asnam Mw 7.1; 1989 Sahel-Tipasa Mw 6.0, and 2003 Zemmouri Mw 6.8). The panchromatic product (0.5 m resolution) includes a black and white band. It covers the visible spectrum’s 0.47 and 0.83 μm wavelengths. Raw and processed images highlight geomorphic markers of late Pleistocene and Holocene tectonic movement determined from marine, lacustrine, and fluvial terraces distribution. Fault scarps traced along triangular facets of folded geological units characterize the seismic potential of tectonic structures with long-term cumulative surface deformation. The contribution of satellite Pleiades images seems to be significant in earthquake geology and, ultimately, in seismic hazard and risk evaluation.