Pyroclastic flow hazard assessment at Somma–Vesuvius based on the geological record

Gurioli, Lucia; Sulpizio, Roberto; Cioni, Raffaello; Sbrana, Alessandro; Santacroce, Roberto; Luperini, W.; Andronico, Daniele

doi:10.1007/s00445-010-0379-2

Cited by 71 publications

(99 citation statements)

References 72 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Cavache and Williams 1992), these lithic-rich PDC deposits, have extents similar to those of pumice-rich PDC deposits (e.g. Gurioli et al 2010) and have a lethal temperature, as we found in this study.…”

Section: Discussionsupporting

confidence: 85%

The historic magmatic-hydrothermal eruption of the Breccia di Commenda, Vulcano, Italy

et al. 2012

Self Cite

View full text Add to dashboard Cite

This is an author version of the contribution published on:Questa è la versione dell 'autore dell'opera: Gurioli, Zanella,Gioncada, Sbrana,Bulletin of Volcanology, 74, 1235-1254, DOI:10.1007. The definitive version is available at: La versione definitiva è disponibile alla URL: AbstractThe historic Breccia di Commenda (BC) explosive eruption of Vulcano (Aeolian Islands, Italy) opened with a phase that generated a grey fine ash layer dispersed to the northwest (Phase 1). The eruption continued with a dilute pyroclastic density current (PDC) that was dispersed to the east, followed by the emplacement of radially distributed, topographically controlled PDC deposits (Phase 2). The last phase of the eruption produced a sequence of accretionary lapilli and grey fine ash dispersed toward the southeast (Phase 3). The most impressive feature of the BC is its high lithic/juvenile clast ratio and the yellow color of the deposits of Phase 2. Lithic fragments are mainly hydrothermally altered rocks, in the silicic and advanced argillic facies. Juvenile fragments, ranging from 20% to 40% by volume, are mainly confined to the ash component of the deposits and comprise rhyolitic to trachyandesite, poorly to non-vesicular fragments. The fine ash fraction of the deposits is richer in S, Cu, Zn, Pb, and As than the BC juvenile lapilli and bombs, and also the juvenile 3 components of other La Fossa units, suggesting that the BC formed in the presence of an anomalously high amount of S and metals. Sulfur and metals may have been carried as aerosols by chloride-and sulfate-bearing micro-crystals, derived from the condensation of magmatic gas in the eruptive cloud. The high content of hydrothermally altered lithic clasts in the deposits suggests that explosions involved the fluid-saturated hydrothermally altered rocks residing in the conduit zone. However, the presence of a juvenile component in the deposits supports the idea that this explosion may have been triggered by the ascent of new magma.We categorize this eruption as magmatic-hydrothermal, to emphasize that in this type of phreatomagmatic eruption the external water was an active hydrothermal system.Rock magnetic temperatures of non-altered lava lithic fragments indicate a uniform deposit temperature for the PDC deposits of between 200 and 260 °C, with a maximum at 280 °C.These homogeneous, relatively low temperatures are consistent with the idea that the Phase 2 explosions involved the expansion of abundant steam from the flashing of the hydrothermal system. In addition, recent paleomagnetic dating of the BC provides an age of between 1000and 1200 AD, younger than that reported in the previously published data, suggesting that previous interpretations and the recent history of La Fossa and Mt. Pilato require reevaluation.

show abstract

Section: Discussionsupporting

confidence: 85%

The historic magmatic-hydrothermal eruption of the Breccia di Commenda, Vulcano, Italy

et al. 2012

Self Cite

View full text Add to dashboard Cite

show abstract

“…Both tephra fallout and PDCs are likely to happen and they could supply fresh pyroclastic material onto the slopes of the volcanic edifice as well as on the Apenninic reliefs toward the northeast, east and southeast of Somma-Vesuvius (Cioni et al, 1999;Gurioli et al, 2010). In this situation, tephra may be remobilized by erosive runoff of the fine-grained upper-part of the deposit and/or by shallow gravitational failures as the coarser-grained underlying deposit is exposed (Zanchetta et al, 2004a;Sulpizio et al, 2006).…”

Section: Multihaz Applied To Somma-vesuviusmentioning

confidence: 99%

“…The natural variability of these eruptions, in terms of tephra-fallout dispersal and PDC inundation, is quite large (Cioni et al, 2008;Gurioli et al, 2010;Sandri et al, 2016;Tierz et al, 2016a). In this paper, we quantify this aleatory uncertainty in pyroclastic volume over different catchments around SommaVesuvius (Figure 5), by computing probabilistic hazard curves (e.g., Rougier et al, 2013) of this variable for tephra fallout and dense PDCs.…”

Section: Tephra-fallout and Pdc-deposit Volumesmentioning

confidence: 99%

A Framework for Probabilistic Multi-Hazard Assessment of Rain-Triggered Lahars Using Bayesian Belief Networks

et al. 2017

View full text Add to dashboard Cite

Volcanic water-sediment flows, commonly known as lahars, can often pose a higher threat to population and infrastructure than primary volcanic hazardous processes such as tephra fallout and Pyroclastic Density Currents (PDCs). Lahars are volcaniclastic flows of water, volcanic debris and entrained sediments that can travel long distances from their source, causing severe damage by impact and burial. Lahars are frequently triggered by intense or prolonged rainfall occurring after explosive eruptions, and their occurrence depends on numerous factors including the spatio-temporal rainfall characteristics, the spatial distribution and hydraulic properties of the tephra deposit, and the pre-and post-eruption topography. Modeling (and forecasting) such a complex system requires the quantification of aleatory variability in the lahar triggering and propagation. To fulfill this goal, we develop a novel framework for probabilistic hazard assessment of lahars within a multi-hazard environment, based on coupling a versatile probabilistic model for lahar triggering (a Bayesian Belief Network: Multihaz) with a dynamic physical model for lahar propagation (LaharFlow). Multihaz allows us to estimate the probability of lahars of different volumes occurring by merging varied information about regional rainfall, scientific knowledge on lahar triggering mechanisms and, crucially, probabilistic assessment of available pyroclastic material from tephra fallout and PDCs. LaharFlow propagates the aleatory variability modeled by Multihaz into hazard footprints of lahars. We apply our framework to Somma-Vesuvius (Italy) because: (1) the volcano is strongly lahar-prone based on its previous activity, (2) there are many possible source areas for lahars, and (3) there is high density of population nearby. Our results indicate that the size of the eruption preceding the lahar occurrence and the spatial distribution of tephra accumulation have a paramount role in the lahar initiation and potential impact. For instance, lahars with initiation volume ≥10 5 m 3 along the volcano flanks are almost 60% probable to occur after large-sized eruptions (∼VEI ≥ 5) but 40% after medium-sized eruptions (∼VEI4). Some simulated lahars can propagate for 15 km or reach combined flow depths of 2 m and speeds of 5-10 m/s, even over flat terrain. Probabilistic multi-hazard frameworks like the one presented here can be invaluable for volcanic hazard assessment worldwide.

show abstract

“…In addition, volcanic eruptions are not the only cause of damage in volcanic areas. For example, lahars and mudflows may not only occur during volcanic unrest, but also may be triggered by heavy rains, months after the eruption, as at Pinatubo in 2001(Hayes et al, 2002 and more recently at Merapi volcano in 2010 (Lavigne et al, 2011;Bignami et al, 2013). On Mount Cameroon, landslides that are not related to contemporary volcanic activity are a major concern (Ayonghe et al, 2004).…”

Section: Hazardmentioning

confidence: 99%

“…This involves a structured collection of expert guesses together with the associated uncertainties. This approach may be applied for case studies such as at Vesuvius, where a large amount of information is available on past volcanic events thanks to historical reports since Roman times, and numerous sedimentology studies (Acocella et al, 2006a;Gurioli et al, 2010, and references therein). In less known volcanoes is an approach that could become more widespread with the sharing and dissemination of historical eruption data (Marzocchi et al, 2004;Sandri et al, 2012).…”

Section: Knowledge Collection At a Target Volcano And Event Tree Consmentioning

confidence: 99%

A method for multi-hazard mapping in poorly known volcanic areas: an example from Kanlaon (Philippines)

Neri

Cozannet

Thierry

et al. 2013

Nat. Hazards Earth Syst. Sci.

View full text Add to dashboard Cite

Hazard mapping in poorly known volcanic areas is complex since much evidence of volcanic and non-volcanic hazards is often hidden by vegetation and alteration. In this paper, we propose a semi-quantitative method based on hazard event tree and multi-hazard map constructions developed in the frame of the FP7 MIAVITA project. We applied this method to the Kanlaon volcano (Philippines), which is characterized by poor geologic and historical records. We combine updated geological (long-term) and historical (short-term) data, building an event tree for the main types of hazardous events at Kanlaon and their potential frequencies. We then propose an updated multi-hazard map for Kanlaon, which may serve as a working base map in the case of future unrest. The obtained results extend the information already contained in previous volcanic hazard maps of Kanlaon, highlighting (i) an extensive, potentially active ~5 km long summit area striking north–south, (ii) new morphological features on the eastern flank of the volcano, prone to receiving volcanic products expanding from the summit, and (iii) important riverbeds that may potentially accumulate devastating mudflows. This preliminary study constitutes a basis that may help local civil defence authorities in making more informed land use planning decisions and in anticipating future risk/hazards at Kanlaon. This multi-hazard mapping method may also be applied to other poorly known active volcanoes

show abstract

Pyroclastic flow hazard assessment at Somma–Vesuvius based on the geological record

Abstract: International audienc

Cited by 71 publications

References 72 publications

The historic magmatic-hydrothermal eruption of the Breccia di Commenda, Vulcano, Italy

The historic magmatic-hydrothermal eruption of the Breccia di Commenda, Vulcano, Italy

A Framework for Probabilistic Multi-Hazard Assessment of Rain-Triggered Lahars Using Bayesian Belief Networks

A method for multi-hazard mapping in poorly known volcanic areas: an example from Kanlaon (Philippines)

Contact Info

Product

Resources

About