88426 - VOLCANIC RISK

Scheda insegnamento

Anno Accademico 2018/2019

Conoscenze e abilità da conseguire

Volcanism is one of the most dramatic and rapid agent of geologic change. Even though less frequent and devastating than earthquakes, any kind of volcano can produce hazardous or deadly phenomena, whether during an eruption or in quiescence conditions, thus inducing risks for densely populated areas around the world. Some eruptions can have a meaningful global impact on Earth’s climate, either with cooling or warming effects, through the ejection of large amounts of ash particles and gases into the atmosphere. Understanding the eruptive behaviour of a volcano is the first step in mitigating volcanic hazards (and risk), eventually taking into consideration some elements of unpredictability inherent to these natural systems. At the end of the course, students will acquire knowledge on the main eruptive processes (lava flows, explosive eruptions, volcano-tectonic collapses, lahars) and their effects on persons, properties and resources and the environment, with a particular focus on the eruptive phenomena that can potentially affect (global) climate changes (ash dispersal, gas emission). Moreover, students will learn about the main parameters for the monitoring of volcanoes, i.e. deformation of the soil, seismicity, and fluid geochemistry, particularly implementing the monitoring techniques based on gas emission in volcanic-hyrothermal systems by means of laboratory experiments on analytical methods. Laboratory activities will also concern the most important models used for volcanic hazards and risk assessment and the mathematical and statistical methods for processing data in terms of volcanic plume dynamics and atmospheric transport of volcanic ash, gravity-driven phenomena (lava flows, pyroclastic currents and lahars) and dispersal of volcanic and hydrothermal gases into the air. The course will be integrated by a field excursion in Italian active volcanic areas (Etna, Stromboli, Vulcano, Vesuvius and Campi Flegrei), including visits to volcanic observatories and seminars of researchers from other institutions about their monitoring.

Programma/Contenuti

The course is arranged into different sections aimed at providing a general framework of knowledge on eruptive activity starting from its magmatic sources to the volcanic edifices on surface, and at defining the main eruption types and depositional mechanisms of the various eruptive processes with a special outcome on the evaluation of volcanic hazard and risk. I – Physical properties of magmas. Dykes and eruptive conduits. II – Features of explosive volcanism. Classification of volcanic activity and eruption types. Magmatic fragmentation. Volcanic plumes and fall deposits. Pyroclastic density currents and their deposits. III - Features and flow dynamics of mafic lava flows (pahoehoe and aa). Features and flow dynamics of silicic lavas: blocky lava flows, rhyolitic lava flows (coulees), volcanic domes. Submarine and subglacial volcanism. IV - Volcano-tectonic collapse structures (calderas and sector collapses). Post- eruption mass gravity flows (debris avalanches, lahar). V - Volcanic hazard maps. Risk mitigation in volcanic areas. Monitoring in volcanic areas. The course will take into account the most famous eruptions in the history of volcanology as examples of good or bad practice of hazard evaluation and risk mitigation. It will be integrated by laboratory activities on gas sampling and measuring and the up-to-date computational systems to extract eruption physical parameters from the features of pyroclastic products. A field excursion in Italian active volcanic areas (Etna, Stromboli, Vulcano, Vesuvius and Campi Flegrei) will complete the course, including also visits to volcanic observatories and monitoring centres.

Teacher in charge: Dott. Federico Lucchi

Collaborator teachers: Dott. Antonio Costa (INGV), Dott. Dmitri Rouwet (INGV)

The course is organized into 32 hours of frontal lessons (4 CFU), 12 hours of laboratory exercise (1 CFU) and 12 hours of field activity (1 CFU)

Testi/Bibliografia

Power Point lecture notes.

• R.A.F. Cas, J.W. Wright, 1987. Volcanic successions: modern and ancient. London Unwin Hyman.

• H. Sigurdsson (Ed.), 2000. Encyclopedia of Volcanoes. Accademic press, San Diego, U.S.A.

• M.J. Branney, P. Kokelaar, 2002. Pyroclastic density currents and the sedimentation of ignimbrites. Geological Society of London, Memoirs 27.

• H.U. Schminke, 2004. Volcanism. Springer-Verlag, Berlin Heidelberg

Metodi didattici

PowerPoint presentations.

Recognition of volcanic rocks and deposits through hand samples or outcrop photographs.

Laboratory exercises on gas measuring

PC activity on softwares and codes for the estimation of eruption physical parametres

Field activity aimed at verifying the learning of the concepts treated during the room lectures.

Modalità di verifica dell'apprendimento

Oral exam.

Strumenti a supporto della didattica

Video-projector.

Hand samples.

Laboratory instruments

Softwares and codes

Orario di ricevimento

Consulta il sito web di Federico Lucchi

Consulta il sito web di Dmitri Rouwet

Consulta il sito web di Antonio Costa