In this paper, we apply an effective method to evaluate relative tectonic activity by applying several morph-tectonic indices that are useful in evaluating topography and tectonics. These indices include stream length-gradient, asymmetric factor, hypsometric index, hypsometric curves, valley floor width to valley height ratio, drainage basin shape, and mountain front sinuosity. The study region of Wadi Al-Arish in northern Sinai Peninsula in northern Egypt is a natural laboratory to examine relative tectonic activity levels for calculating morpho-tectonic indices of several catchments and sub-catchments rather than an individual catchment. Northern Sinai, comprising the Waid Al-Arish area, is characterized by several large inversion anticline folds. The cumulative results extracted from morpho-tectonic indices ae presented as a new index, namely relative tectonic activity level (RTAL), which we classified into four levels: low, moderate, high, and very high relative tectonic activity. Therefore, the study region provides different levels of relative tectonic activity resulting from fault patterns affecting the northern Sinai inversion forms. The paper examines the concept that regions with various levels of tectonic activity are associated with specific values of RTAL.

The Gulf of Suez area represents one of the most famous tectonic structures in the Red Sea, with a long history of low-, moderate-, and high-intensity earthquakes. This paper provides geomorphic analytics of the fault-initiated mountain front sinuosity (S_mf) and the stream gradients that cross various segments of the fault scarps. The results from the mountain front sinuosity index (S_mf) and the valley floor width to valley height ratio index (V_f) suggest different levels of activities along the different fault segments. The analysis of the stream gradient index reflects that streams running through the fault segments mostly have higher river gradient values identified by knickpoint spots. With regard to the strike variation in the mountain front sinuosity, valley floor width to valley height ratio, and stream river gradients, the results are compatible with the predominant mountain front’s relief. Finally, the calculated geomorphic results show that the eastern segments might reflect higher seismic signals with respect to the central and western segments of the entire Wadi Araba basin. Thus, more careful studies are required to investigate seismic hazard possibilities.