Options
Olivares, Lucio
Loading...
Preferred name
Olivares, Lucio
ORCID
2 results
Now showing 1 - 2 of 2
- PublicationRestrictedShallow landslide generation at La Fossa cone, Vulcano island (Italy): a multidisciplinary perspective(2019)
; ; ; ; ; ; ; ; ; ; ; Several shallow landslides occurred at La Fossa cone (Vulcano Island, Aeolian Archipelago, Italy) in the last 30 years, during both unrests and periods of quiet volcanic activity. The main event occurred in 1988, during a volcanic unrest, when a landslide collapsed into the sea from the NE flank of La Fossa cone, producing a small tsunami. Hydrothermal activity has been suggested as a potential trigger for landslide generation in this area. However, no specific investigations were carried out to test this hypothesis. With the aim of filling this gap, we studied the mineralogy and hydraulic conductivity of La Fossa cone deposits, the relationships between shallow hydrothermal circulation and rainfall dynamics and their role in triggering slope failures. We also measured rainfall rate, volumetric soil moisture content and soil suction at two automated stations installed in areas with and without active hydrothermal circulation.We found that hydrothermally altered low-conductivity materials show higher background water contents and lower soil suctions than pristine deposits, and their water content is modulated by impulsive increments following rainfalls. This behaviour is due to the combination of lower permeability and direct condensation of hydrothermal vapour. We conclude that shallow hydrothermal circulation produces conditions for slope failures following transients in soil moisture content caused by rainfall infiltration. These considerations allow to identify the areas immediately NWand SE of the 1988 landslide as the most prone to future mass movements.216 8 - PublicationOpen AccessShallow fluid circulation at Vulcano Island (Aeolian Islands, Italy): a possibile trigger for flank instability?(2008-04-14)
; ; ; ; ; ; ;Madonia, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Lodato, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Olivares, L.; Dipartimento di Ingegneria Civile, Seconda Universita’ degli Studi di Napoli ;Tommasi, P.; CNR-IGAG, Roma ;Costa, M.; Università degli Studi di Palermo ;Madonia, I.; Università degli Studi di Palermo; ; ; ; ; The crater of “La Fossa” at Vulcano Island (Aeolian Islands, Italy) since the last eruption, occurred in 1890, is characterized by an intense fumarolic activity. The main fumarolic field is located on the north flank of the inner crater, whereas the release of water vapour from soil spans all over the entire vent, including the sea-facing slopes. The steepest slopes of La Fossa crater have been interested during the last 20 years by instability phenomena, the most important of which was a landslide detached from the sea-facing NE flank in 1988, during the most significant volcanic unrest that affected Vulcano Island in recent times. The search for a possible link between volcanic activity and landslides has been the object of several recent studies, carried out since 2004 within the research activities promoted by the Italian Civil Protection Department, mainly focused on the role played by space and time variability of the fumarolic activity as a possible trigger for flank instability. The triggering mechanisms should be linked to the circulation of water of volcanic origin, deriving from the underground condensation of vapour, able to modify the geo-technical parameters of the volcanic products and/or to create detachment surfaces over which or from which landslides could be generated. The spatial extension of the water vapour release from the soil, with specific reference to the slopes affected in the past by mass movements, has been reconstructed by ground-based and airborne remote-sensed thermal surveys. Once located, a network of continuous monitoring stations has been installed on the main soil thermal anomalies, collecting data of temperature at different depths and suction, with the aim of ascertaining the existence of variations in the water content of the soil due to endogenous sources. The preliminary data acquired show a good correlation between soil temperature and suction, highlighting how their variations seems to be directly linked to the activity level of the volcanic system and, at least, confirming the possible role of water deriving from condensation of volcanic vapour as a trigger for slope instability.245 99