Lake Albano: bathymetry and level changes
Lake Albano is situated in the Colli Albani volcanic district, about 20 km SE of the city centre of Rome. It is 287 m above sea level and is the deepest of the volcanic crater lakes of Italy, presently being 167 m deep. It is 3.5 km long and 2.3 km wide with an area of about 6 km2. The crater has a long history, which starts with the formation of the Albano crater c. 70 ka BP, and shows evidence of human settlements since pre-historical times. Geological evidence indicates that a catastrophic overflow of the lake occurred in 398 BCE due to a rapid increase in the water level. This phenomenon persuaded the Romans to excavate an artificial outlet though the crater wall to control the lake level. The lake is thought to be a hazard for the surrounding human settlements and the city of Rome, so high-resolution multibeam bathymetry of Lake Albano was carried out for the Italian Dipartimento della Protezione Civile in order to evaluate the potential for CO2 storage and eruption from the lake. The shape of the crater floor was mapped in two and three dimensions. Here, we show the main submerged morphological features and a brief history of the changes in lake level, which still affect the basin today.
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The Colli Albani Volcano
The Colli Albani volcano (also Alban Hills volcano) is the large quiescent volcanic field that dominates the Roman skyline. The Colli Albani is one of the most explosive mafic calderas in the world, associated with intermediate to large volume ignimbrites. At present it shows signs of unrest, including periodic seismic swarms, ground uplift and intense diffuse degassing, which are the main short-term hazards. New studies have discovered deposits related to previously unknown pre-Holocene and Holocene volcanic and phreatic activity. In the fourth Century B.C.E. Roman engineers excavated a tunnel through the Albano maar crater wall to keep the lake from breaching the rim and flooding the surrounding countryside, events that had previously destroyed this region several times.
The Colli Albani Volcano contains 21 scientific contributions on stratigraphy, volcanotectonics, geochronology, petrography and geochemistry, hydrogeology, volcanic hazards, geophysics and archaeology, and a new 1:50 000 scale geological map of the volcano. The proximity to Rome and the interconnection between volcanic and human history also make this volcano of interest for both specialists and non-specialists.