Lava flow hazard prediction and monitoring with UAS: a case study from the 2014–2015 Pāhoa lava flow crisis, Hawai‘i

Abstract. Lava flow simulations help to better understand volcanic hazards and may assist emergency preparedness at active volcanoes. We demonstrate that at Fogo Volcano, Cabo Verde, such simulations can explain the 2014–2015 lava flow crisis and therefore provide a valuable base to better prepare for the next inevitable eruption. We conducted topographic mapping in the field and a satellite-based remote sensing analysis. We produced the first topographic model of the 2014–2015 lava flow from combined terrestrial laser scanner (TLS) and photogrammetric data. This high-resolution topographic information facilitates lava flow volume estimates of 43.7 ± 5.2 × 106 m3 from the vertical difference between pre- and posteruptive topographies. Both the pre-eruptive and updated digital elevation models (DEMs) serve as the fundamental input data for lava flow simulations using the well-established DOWNFLOW algorithm. Based on thousands of simulations, we assess the lava flow hazard before and after the 2014–2015 eruption. We find that, although the lava flow hazard has changed significantly, it remains high at the locations of two villages that were destroyed during this eruption. This result is of particular importance as villagers have already started to rebuild the settlements. We also analysed satellite radar imagery acquired by the German TerraSAR-X (TSX) satellite to map lava flow emplacement over time. We obtain the lava flow boundaries every 6 to 11 days during the eruption, which assists the interpretation and evaluation of the lava flow model performance. Our results highlight the fact that lava flow hazards change as a result of modifications of the local topography due to lava flow emplacement. This implies the need for up-to-date topographic information in order to assess lava flow hazards. We also emphasize that areas that were once overrun by lava flows are not necessarily safer, even if local lava flow thicknesses exceed the average lava flow thickness. Our observations will be important for the next eruption of Fogo Volcano and have implications for future lava flow crises and disaster response efforts at basaltic volcanoes elsewhere in the world.

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Retrospective validation of a lava-flow hazard map for Mount Etna volcano

Annals of Geophysics ◽

10.4401/ag-5345 ◽

2011 ◽

Vol 54 (5) ◽

Author(s):

Annalisa Cappello ◽

Annamaria Vicari ◽

Ciro Del Negro

Keyword(s):

Lava Flow ◽

Mount Etna ◽

Hazard Map ◽

Etna Volcano ◽

Lava Flow Hazard

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Optimizing barrier placement for lava flow hazard and risk mitigation

10.5194/egusphere-egu2020-8735 ◽

2020 ◽

Author(s):

Giuseppe Bilotta ◽

Annalisa Cappello ◽

Veronica Centorrino ◽

Claudia Corradino ◽

Gaetana Ganci ◽

...

Keyword(s):

Lava Flow ◽

Risk Mitigation ◽

Flow Direction ◽

Economic Loss ◽

Lava Flows ◽

Mount Etna ◽

Area Of Interest ◽

Lava Flow Hazard ◽

Mitigation Action ◽

The Impact

<p>Mitigating hazards when lava flows threaten infrastructure is one of the most challenging fields of volcanology, and has an immediate and practical impact on society. Lava flow hazard is determined by the probability of inundation, and essentially controlled by the topography of the area of interest. The most common actions of intervention for lava flow hazard mitigation are therefore the construction of artificial barriers and ditches that can control the flow direction and advancement speed. Estimating the effect a barrier or ditch can have on lava flow paths is non-trivial, but numerical modelling can provide a powerful tool by simulating the eruptive scenario and thus assess the effectiveness of the mitigation action. We present a numerical method for the design of optimal artificial barriers, in terms of location and geometric features, aimed at minimizing the impact of lava flows based on the spatial distribution of exposed elements. First, an exposure analysis collects information about elements at risk from different datasets: population per municipality, distribution of buildings, infrastructure, routes, gas and electricity networks, and land use; numerical simulations are used to compute the probability for these elements to be inundated by lava flows from a number of possible eruptive scenarios&#160; (hazard assessment) and computing the associated economic loss and potential destruction of key facilities (risk assessment). We then generate several intervention scenarios, defined by the location, orientation and geometry (width, length, thickness and even shape) of multiple barriers, and compute the corresponding variation in economic loss. Optimality of the barrier placement is thus considered as a minimization problem for the economic loss, controlled by the barrier placement and constrained by the associated costs. We demonstrate the operation of this system by using a retrospective analysis of some recent effusive eruptions at Mount Etna, Sicily.</p>

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Modelling and simulation of a lava flow affecting a shore platform: a case study of Montaña de Aguarijo eruption, El Hierro (Canary Islands, Spain)

Journal of Maps ◽

10.1080/17445647.2021.1972853 ◽

2021 ◽

Vol 17 (2) ◽

pp. 502-511

Author(s):

C. Prieto-Torrell ◽

A. Rodriguez-Gonzalez ◽

M. Aulinas ◽

J. L. Fernandez-Turiel ◽

M.C. Cabrera ◽

...

Keyword(s):

Lava Flow ◽

Canary Islands ◽

Modelling And Simulation ◽

El Hierro ◽

Shore Platform

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Map showing lava-flow hazard zones, Island of Hawaii

10.3133/mf2193 ◽

1992 ◽

Cited By ~ 1

Keyword(s):

Lava Flow ◽

Lava Flow Hazard

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Fast short-term lava flow hazard assessment with graph theory

10.5194/egusphere-egu2020-13218 ◽

2020 ◽

Author(s):

Veronica Centorrino ◽

Giuseppe Bilotta ◽

Annalisa Cappello ◽

Gaetana Ganci ◽

Claudia Corradino ◽

...

Keyword(s):

Graph Theory ◽

Lava Flow ◽

Graph Representation ◽

Computational Time ◽

Hazard Map ◽

Short Term ◽

Flow Paths ◽

Lava Flow Hazard ◽

Mt Etna

<p>We explore the use of graph theory to assess short-term hazard of lava flow inundation, with Mt Etna as a case study. In the preparation stage, we convert into a graph the long-term hazard map produced using about 30,000 possible eruptive scenarios calculated by simulating lava flow paths with the physics-based MAGFLOW model. Cells in the original DEM-based representation are merged into graph vertices if reached by the same scenarios, and for each pair of vertices, a directed edge is defined, with an associated lava conductance (probability of lava flowing from one vertex to the other) computed from the number of scenarios that reach both the start and end vertex. In the application stage, the graph representation can be used to extract short-term lava flow hazard maps in case of unrest. When a potential vent opening area is identified e.g. from monitoring data, the corresponding vertices in the graph are activated, and the information about lava inundation probability is iteratively propagated to neighboring vertices through the edges, weighted according to the associated lava conductance. This allows quick identification of potentially inundated areas with little computational time. A comparison with the deterministic approach of subsetting and recomputing the weights in the long-term hazard map is also presented to illustrate benefits and downsides of the graph-based approach.</p>

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