New insights on Panarea volcano from terrestrial, marine and airborne data

The Panarea and Albano active volcanoes (Italy) have been surveyed during the recent years under multidisciplinary programs funded by the Italian Department of the Civil Protection and INGV. These volcanoes produced dramatic impacts on the environment as well as on human settlements since historical times. The survey methodologies such as GPS, aerial digital photogrammetry, aerial laser scanning, multibeam bathymetry and geological observations, can be integrated for a detailed morphological reconstruction of sub-aerial and contiguous submarine or sub lacustrine areas involved in geophysical phenomena. Besides, the underwater portions along the coastlines often can be adequately surveyed merging bathymetric acquisitions in low depth water with aerial photogrammetry, producing detailed digital model on the zones between sub-aerial and submarine portions. At Panarea, on November 3th, 2002, a submarine gas eruption started in the shallow area between Lisca Bianca, Bottaro and Lisca Nera islets. Hence, a subaerial and sea bottom DEM of Panarea volcano was obtained merging aerial digital photogrammetry, aerial laser scanning and multibeam bathymetry carried out in 2002 and 2003. GPS data from the local network, show rates of motion and strain values typical of volcanic areas and in agreement with the NE-SW and NW-SE tectonic systems. The latter coincide with the main pathways for the upwelling of hydrothermal fluids. Deformations across the area, inferred by GPS data, can be interpreted as the response to the surface of the deflation of the hydrothermal system reservoir which progressively reduced its pressure after the 2002 gas eruption. The Albano volcano is the deepest volcanic lake in Italy which fills the youngest maar of the Colli Albani volcano. The lake, which is only a few km far from surroundings of Rome, experienced in the historical times dramatic level changes and overflows. Hazardous lake rollovers and CO release cannot be excluded because the Albano volcano shows active geodetic ground deformation, gas emissions and periodic seismic swarms. In 2006, a very high resolution DEM from the combination of bathymetric and LIDAR airborne surveys of the crater lake was performed. Results shows that the lake floor is made by coalescent and partly overlapping craters and wide flat surfaces separated by some evident scarps subjected to slides. Here we show and discuss some key issues for volcanic hazard related with monitoring strategies of surface deformations for these active volcanoe