The dark side of the Albano crater lake

Abstract

The Albano Lake is the deepest volcanic lake among the volcanoes located in the Italian Peninsula. It belongs to the Colli Albani volcanic complex whose last largest eruptions are dated back to about ∼30 Kyr, although minor events likely occurred during historical times at 7000 years BP or earlier. After the end of the volcanic activity the Crater of Albano became a lake whose level changes have been known since historical times. In November 2005, the first very high resolution bathymetric survey of the Albano Lake was performed by means of a multibeam echo sounder, integrated with the GPS/RTK positioning technique. Special effort was devoted to produce a high resolution morphobathymetric map, which aims to provide a Digital Terrain Model of the lake floor for wide applications. The surveys did not revealed significant gas exhalative centres, which should indicate a current active gas release from the lake floor. Here we show the technical details of the bathymetric surveys, the very high resolution bathymetric map and the main morphological features of the Albano Lake bottom.