(French.) An intermittent resurgence or exsurgence, active only in wet seasons. May act alternatively as a swallow hole and as a rising according to ground-water conditions [10]. Opening in karstic terrane which acts as a discharge spring during high potentiometric surface and as a swallet during low potentiometric surface. Sea estavelles are known to exist [20]. Synonyms: (French.) estavelle; (German.) Estavelle; (Greek.) estavella; (Italian.) estavella; (Russian.) estavella; (Spanish.) estavela; (Turkish.) su batar cikari; (Yugoslavian.) estavela, ponor-rigalo.