A key question to adequately understand the circulation of the Western Mediterranean sea is the dynamics of the eddies within the Algerian basin. Such eddies in most cases are generated by instabilities of the Algerian current and last for several months within the basin. To adequatley study their dynamics and evolution we need observational data able to track them over their lifetime. This may be done efficiently by means of remote sensing data and commonly the infrared thermal images are used as a source to identify such mesoscale structures. In this work we present some results obtainned by analyzing the Sea Level Anomalies (SLA) maps, with a technique based on the second Galilean-Invariant of the velocity gradient tensor.This technique allows us to clearly detect the core regions of the mesoscale eddies within the Algerian basin. The analysis applied on SLA maps between 1992 and 1999 show that this methodology is coherent with previous studies and is able to distinguish two interacting eddies which can not be distinguished from visual inspection. It reveals that eddies follow a circuit in the eastern part of the Algerian basin composed by three main branches. In particular,The observations and the analysis show a region in the Algerian coast, near 3 º E, where eddies detach and drift westwards following the continental slope south of Ibiza Island

36e Congrès de la CIESM : 36th CIESM Congress, 24-28 September 2001, Monte-Carlo.-- 1 page, 3 figures