New Evidence of Active Faulting Along the Ain Smara Fault in the Constantine Province (North East Algeria)

Abstract

The city of Constantine is one of the most populated cities in Algeria, located 300 km east of Algiers and represents the metropolis of eastern Algeria. In 1985, this city and its surroundings were shaken by an Ms = 6.0 earthquake generated by a pure left lateral strike-slip fault. This paper presents new results from multi-approach investigations carried out along the fault that generated this earthquake. The fault is composed of, at least, two main segments. The first segment responsible for the 1985 event displays clear geomorphic features of cumulative Quaternary displacement, which are manifested by a homogenous behavior of the hydrographic network in the epicentral area. However, the second segment was not reactivated during the earthquake. This segment shows evidence of recent Quaternary surface rupture with a left transpres-sional movement.