CHEMICAL CHARACTERS OF CRATER LAKES IN THE AZORES AND ITALY - THE ANOMALY OF LAKE ALBANO

Investigations have been carried out on crater lakes in areas of recen t volcanism in the Azores and in Italy, with the aim of detecting poss ible evidence of residual anomalies associated with past volcanic acti vities; data from crater lakes of Cameroon have been considered for co mparison. Among the physical-chemical characters taken into account, t he increases of temperature, ammonium and dissolved carbon dioxide wit h depth are interpreted as providing information about the contributio n of endogene fluids to the lake water budgets. The greater extent of such evidence at Lakes Monoun and Nyos (Cameroon) appears associated w ith the disasters that occurred there during the last decade; some sim ilarities observed at Lake Albano (Italy) suggest a potential instabil ity also for this crater lake.