Long-Term Probabilistic Volcanic Hazard Assessment Using Open and Non-open Data: Observations and Current Issues

Abstract

Probabilistic volcanic hazard assessment (PVHA) has become the paradigm to quantify volcanic hazard over the last decades. Substantial aleatory and epistemic uncertainties in PVHA arise from complexity of physico-chemical processes, impossibility of their direct observation and, importantly, a severe scarcity of observables from past eruptions. One factor responsible for data scarcity is the infrequency of moderate/large eruptions; other factors include lack of discoverability and accessibility to volcanological data. Open-access databases can help alleviate data scarcity and have significantly contributed to long-term PVHA of eruption onset and size, while are less common for data required in other PVHA components (e.g., vent opening). Making datasets open is complicated by economical, technological, ethical and/or policy-related challenges. International synergies (e.g., Global Volcanism Program, WOVOdat, Global Volcano Model, EPOS) will be key to facilitate the creation and maintenance of openaccess databases that support Next-Generation PVHA. Additionally, clarification of some misconceptions about PVHA can also help progress. Firstly, PVHA should be understood as an expansion of deterministic, scenario-based hazard assessments. Secondly, a successful PVHA should sometimes be evaluated by its ability to deliver useful and usable hazard-related messages that help mitigate volcanic risk. Thirdly, PVHA is not simply an end product but a driver for research: identifying the most relevant sources of epistemic uncertainty can guide future efforts to reduce the overall uncertainty. Broadening of the volcanological community expertise to statistics or engineering has already brought major breakthroughs in long-term PVHA. A vital next step is developing and maintaining more open-access datasets that support PVHA worldwide.

Event Trees and Epistemic Uncertainty in Long‐Term Volcanic Hazard Assessment of Rift Volcanoes: The Example of Aluto (Central Ethiopia)

“…Nevertheless, it must be noted that one current problem with this approach is that the analogs identified for rift volcanoes may tend to be data‐scarce themselves (e.g., very few to no eruptions stored in the global databases). Consequently, there is an urgent need to incorporate recent volcanological knowledge on rift volcanism (e.g., Clarke, 2020; Clarke et al, 2019; Fontijn et al, 2010, 2012, 2018; Hunt et al, 2019, 2020; Hutchison et al, 2018; Hutchison, Biggs, et al, 2016; Hutchison, Fusillo, et al, 2016; Hutchison, Pyle, et al, 2016; Martin‐Jones et al, 2017; McNamara et al, 2018; Rapprich et al, 2016; Siegburg et al, 2018; Vye‐Brown et al, 2016; Wadge et al, 2016) into relevant databases that can be used to compute PVHA (Tierz, 2020).…”

“…Therefore, quantifying volcanic hazard is a priority for the volcanological community, and methods have increasingly been developed over recent decades (e.g., Aspinall et al, 2003;Bayarri et al, 2009;Bebbington, 2013Bebbington, , 2014Bebbington, , 2015Bevilacqua et al, 2016Bevilacqua et al, , 2017Connor et al, 2001Connor et al, , 2012Hincks et al, 2014;Jenkins et al, 2012;Marzocchi et al, 2004Marzocchi et al, , 2008Marzocchi et al, , 2010Newhall & Hoblitt, 2002;Sandri et al, 2012Sandri et al, , 2018Selva et al, 2014;Tierz et al, 2017;and many others, cf. Connor et al, 2015;Marzocchi & Bebbington, 2012;Poland & Anderson, 2020;Tierz, 2020). Volcanic hazard quantification is particularly urgent in Africa, where data scarcity and infrequent eruptions pose particular challenges.…”

“…Volcanological knowledge and supporting data sets are increasing in the form of: geological maps, regional and local pyroclastic stratigraphies, physical interpretations of volcanic processes, radiometric dates, and geochemical analyses (Clarke, 2020; Clarke et al, 2019; Fontijn et al, 2010, 2011, 2012, 2018; Hunt et al, 2019; Hutchison, Pyle, et al, 2016; Hutchison et al, 2018; Iddon et al, 2019; Martin‐Jones et al, 2017; McNamara et al, 2018; Rapprich et al, 2016). The collection and compilation of such volcanological data sets are of paramount importance to quantify volcanic hazard (e.g., Tierz, 2020) and also to underpin the design and implementation of volcano disaster risk reduction strategies in Ethiopia and the wider East African region.…”

Probabilistic Volcanic Hazard Assessment for Pyroclastic Density Currents From Pumice Cone Eruptions at Aluto Volcano, Ethiopia

“…For any volcano, it is essential to understand the behavior of the system in order to tailor the methodology for PVHA to (1) minimize epistemic uncertainty; gaining the most precise picture possible; and (2) to evaluate aleatory uncertainty, to present a result that reflects an inherently uncertain volcanic system. This understanding is gained through field, laboratory and remote sensing investigations (e.g., Tierz, 2020). In the case of this work, such investigations played a central role, they:…”

Editorial: Field Data, Models and Uncertainty in Hazard Assessment of Pyroclastic Density Currents and Lahars: Global Perspectives

“…Woo, 1999;Connor et al, 2001;Marzocchi et al, 2004;Sparks and Aspinall, 2004;Marzocchi and Bebbington, 2012) should ideally be incorporated into the mass-flow hazard assessment (e.g., Bayarri et al, 2009Bayarri et al, , 2015Sandri et al, 2014Sandri et al, , 2018Spiller et al, 2014;Neri et al, 2015;Mead et al, 2016;Tierz et al, 2016Tierz et al, , 2017Tierz et al, , 2018Bevilacqua et al, 2017Bevilacqua et al, , 2019Mead and Magill, 2017;Wolpert et al, 2018;Hyman et al, 2019;Rutarindwa et al, 2019). At the core of any volcanic hazard assessment resides the volcanological knowledge available for the volcano of interest and/or analogous ones, including information about the sources of uncertainty (e.g., Newhall and Hoblitt, 2002;Aspinall et al, 2003;Sandri et al, 2012;Pallister et al, 2019;Tierz et al, 2019Tierz et al, , 2020Cioni et al, 2020).…”