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.
Volcanic activity of the Lake Albano Maar in Roman history and mythology
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Published:January 01, 2010
Abstract
The polygenetic Albano maar is the most recent centre of the Colli Albani volcano. Phreatic activity at the maar occurred throughout the Holocene. This paper summarises the close relationships between the activity of the maar and the history of settlement in the Roman region. Repeated lahars associated to the lake overflows occurred along the northwestern slope of the maar. The last catastrophic overflow occurred in 398 B.C.E., after which the Romans excavated a 1.5 km long drain-tunnel through the maar crater wall, which has since kept the lake 70 m below the lowest point of the rim. This tunnel drain may be regarded as the first construction made to mitigate a volcanic hazard in history. The surprising and still largely unknown results of this study are very important to understand the history of settlement of the area and to assess the hazard of the Roman region.