Probability map of vent opening at Campi Flegrei, Italy
Probability map of vent opening at Campi Flegrei, Italy
Probability map of vent opening at Campi Flegrei, Italy
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<strong>Probability</strong> <strong>map</strong> <strong>of</strong> <strong>vent</strong> <strong>opening</strong> <strong>at</strong><strong>Campi</strong> <strong>Flegrei</strong>, <strong>Italy</strong>J. Selva, , M. Di Vito, W. Marzocchi, G. Orsi, , M. Quaglino, , and L. SandriFounded by the projectDPC V3-2 <strong>Campi</strong> <strong>Flegrei</strong>INGVIUGG, Perugia, , Italia, 2-13/07/2007 – Session VS008
IntroductionGrid definition:Sp<strong>at</strong>ial definitionPrior model:Theoretical beliefs…Posterior model:… and past d<strong>at</strong>aSp<strong>at</strong>ial filter:Final <strong>map</strong>Points to take homeINGVIUGG, Perugia, , Italia, 2-13/07/2007 – Session VS008
Introduction<strong>Probability</strong> <strong>map</strong> <strong>of</strong> <strong>vent</strong> <strong>opening</strong>: sp<strong>at</strong>ialconditional probability for the next <strong>vent</strong> <strong>opening</strong>given an eruption occurs1. Immedi<strong>at</strong>e use: to evalu<strong>at</strong>e the most dangerousareas <strong>of</strong> the calderaland-use planning2. Important factor <strong>of</strong> VH, especially in calderasdesigned to represent a meaningfulestim<strong>at</strong>ion <strong>of</strong> the probability <strong>at</strong> node 4 in BETINGVIUGG, Perugia, , Italia, 2-13/07/2007 – Session VS008
Grid definitionSp<strong>at</strong>ial definition1. We define rectangular area containing the caldera withdimension 14 km x 12.5 Km2. The area is divided in 28x25 squares (700 loc<strong>at</strong>ions)Each loc<strong>at</strong>ion:• has dimension <strong>of</strong> 500m x 500m, rel<strong>at</strong>ed to thesp<strong>at</strong>ial definition <strong>of</strong> d<strong>at</strong>a• is assumed homogeneousINGVIUGG, Perugia, , Italia, 2-13/07/2007 – Session VS008
Posterior modelCriteriaD<strong>at</strong>a referred to the present st<strong>at</strong>e <strong>of</strong> the calderaD<strong>at</strong>a • Eruptions from third epoch (19 e<strong>vent</strong>s)• Monte NuovoPosterior distribution<strong>of</strong> each loc<strong>at</strong>ion• Bayes theorem• D<strong>at</strong>a are assumed independent• Each <strong>vent</strong> assumed in only 1 loc<strong>at</strong>ion[θ | y] ∝ [θ] prior [y | θ]Posteriormodel (prior)d<strong>at</strong>a (likelihood)INGVIUGG, Perugia, , Italia, 2-13/07/2007 – Session VS008
Results: posteriorProduced with BET_EFINGVIUGG, Perugia, , Italia, 2-13/07/2007 – Session VS008
Sp<strong>at</strong>ial filterNearest neighbors cannot have too different probabilities(lack <strong>of</strong> knowledge)…Gaussian filterσ = 500 m (grid dimension)< " i> filt=700#j=1< " j> w ij700# w ijj=1INGVGauss(d;0,σ)d = distance from 0!w ij = Gauss(d ij ;,x i ,σ)d ij = distance between loc<strong>at</strong>ions i and jx i = position <strong>of</strong> the loc<strong>at</strong>ion iIUGG, Perugia, , Italia, 2-13/07/2007 – Session VS008
Results: posterior filteredProduced with BET_EFINGVIUGG, Perugia, , Italia, 2-13/07/2007 – Session VS008
Results: posterior filteredProduced with BET_EFINGVIUGG, Perugia, , Italia, 2-13/07/2007 – Session VS008
Results: posterior filteredProduced with BET_EFINGVIUGG, Perugia, , Italia, 2-13/07/2007 – Session VS008
Points to take homeThe model used… <strong>map</strong>s the sp<strong>at</strong>ial conditional probability for the next <strong>vent</strong> <strong>opening</strong> given aneruption occurs (useful to evalu<strong>at</strong>e most dangerous areas) uses all available inform<strong>at</strong>ion (theoretical beliefs and d<strong>at</strong>a) considers only consolid<strong>at</strong>e and complete inform<strong>at</strong>ion assuring accuracy evalu<strong>at</strong>es epistemic uncertainties is designed to be included in the more general Volcanic Hazard assessment <strong>at</strong><strong>Campi</strong> <strong>Flegrei</strong> within the Bayesian E<strong>vent</strong> Tree frameworkINGVIUGG, Perugia, , Italia, 2-13/07/2007 – Session VS008
Points to take home… more on BET_EF <strong>at</strong> the IUGGThursday 12 July, 0230 PM (session VS013)Dep. <strong>of</strong> Chemistry, Room A“Real-time volcanic hazard evalu<strong>at</strong>ion during a volcanic crisis: BET_EFand MESIMEX Experiment”Thursday 12 July, 0530-0900 PM (IAVCEI workshop)Academy <strong>of</strong> Fine Arts, Room 16“Eruption Forecasting through the Bayesian E<strong>vent</strong> Tree: Moving fromtheory to practice with the s<strong>of</strong>tware package BET_EF”Contact: warner.marzocchi@ingv.itselva@bo.ingv.itFriday 13 July, 1000 AM (session VS012)Academy <strong>of</strong> Fine Arts, Room 6“BET <strong>at</strong> <strong>Campi</strong> <strong>Flegrei</strong> and Vesuvius”INGVIUGG, Perugia, , Italia, 2-13/07/2007 – Session VS008
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