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

Recent subaerial volcanism at El Hierro Island (Canary Islands, Spain) consists of monogenetic volcanic fields. This volcanism generated cinder cones, tephra air-fall deposits, and lava flows. The lava flows reach several kilometres in length extending through shore platforms and, sometimes, penetrating under the sea level. The volcanic landforms of El Hierro convert it into a natural laboratory for topographic and morphometric modelling and lava flow simulations. We perform the modelling and simulation of the Montaña de Aguarijo eruption, a cinder cone at the NE rift. The associated lava flow channelled through a V-shaped ravine until reaching a cliff, where formed cascades. The flow spread at the cliff base over a platform before reaching the sea modifying the coastline. Different maps were designed to show the results, including the geomorphologic reconstruction of the area affected by this eruption and the lava flow simulations obtained with the Q-LavHA plugin. © 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of Journal of Maps

Comparison of real and simulated lava flows in the Holocene volcanism of Gran Canaria (Canary Islands, Spain) with Q-LavHA: contribution to volcanic hazard management

Lava flow simulations are valuable tools for forecasting and assessing the areas potentially affected by new eruptions, interpreting past volcanic events and understanding the lava flow behaviour’s controls. Q-LavHA (v 2.0) plug-in of Mossoux et al. (Mossoux et al., Comput Geosci 97:98–109, 2016) combines and improves existing deterministic (FLOWGO) and probabilistic ("Maximum Length" and "Decreasing Probability") codes which allow calculating the probability of lava flow spatial propagation and terminal length. We investigate the Q-LavHA algorithm’s effectiveness in twenty Holocene ʻaʻā lava flows of Gran Canaria (Canary Islands). Pre-eruptive and updated digital elevation models (DEMs) (25 m of resolution) and associated topographic and morphometric parameters have been used as essential input data to simulate the lava flows. Besides, thermo-rheological properties of the studied Holocene lavas have also been provided in the deterministic approach. The probabilistic lava flow maps produced by Q-LavHA and the fitness indexes calculated for assessing the simulated lava flow’ accuracy indicate that the probabilistic "Maximum Length" constraint provides the best simulations. By using this method, many of the simulations in Gran Canaria almost overlap the real lava flow entirely even if overestimated areas are, in some cases, relatively high. By contrast, underestimated areas are generally low. The best results are those in which the highest inundation probability is observed within the main channel where the actual lava flow is emplaced, and even if overestimated areas are high, they are associated with low pixel inundation.Financial support was provided by the Cabildo de Gran Canaria Research Program "Simon Benitez Padilla" (CPH249/16) and by Project LAJIAL (ref. PGC2018-101027-B-I00, MCIU/AEI/ FEDER, EU). This study was carried out in the framework of the Research Consolidated Groups GEOVOL (Canary Islands Government, ULPGC) and GEOPAM (Generalitat de Catalunya, 2017 SGR 1494).Peer reviewe

Lava deltas, a key landform in oceanic volcanic islands: El Hierro, Canary Islands

International audienc

Volcanoes in motion: the LAJIAL research project in El Hierro Geopark (Canary Islands)

[EN] The LAJIAL research project (PGC2018-101027-B-I00) is dedicated to studying the geochronology and petrogenesis of Holocene volcanism on the island of El Hierro (Canary Islands). Its objectives include disseminating its results, for which, among other activities, eight informative panels were designed for the El Hierro Geopark that would be exhibited in its visitor centers and, on an itinerant basis, in the primary and high schools of the island. The format chosen for the exhibition was self-rolling panels (roll-ups) 1 m wide by 2 m high, easily transportable, and highly protective for the printed content. The Geopark of El Hierro was included in the UNESCO Global Geoparks network in 2014 for the international relevance of its volcanic edifices and morphologies.Project LAJIAL (ref. PGC2018-101027-B-I00, MCIU/AEI/FEDER, EU)Research Consolidated Group GEOVOL (Canary Islands Government, ULPGC)Research Consolidated Group GEOPAM (Generalitat de Catalunya, 2017 SGR 1494)Peer reviewe

Importance of Holocene sea level rise in the development of coastal platforms enabling lava delta progradation in El Hierro, Canary Islands

Marine and subaerial erosion of volcanic ocean islands form coastal cliffs and shore platforms, particularly during stable sea levels. Posterosional lava flows can spill over these coastal cliffs and fill the platforms, leading to the progradation of lava deltas. El Hierro Island, Canary Islands, exemplifies a rocky coast with an active sea-cliff profile, reflecting its early evolutionary stage as a young ocean volcanic island with no fringing reef. The occurrence of a contemporary insular shelf formed during the Holocene sea-level highstand (<7 ka) allows constraining the ages of those eruptions forming lava deltas affecting this geomorphological landform. A detailed bathymetry around the island allowed us to distinguish 17 eruptions fulfilling this criterion. The Montaña del Tesoro, which occurred about 1050 years BP, is one of these eruptions and was selected as a case study for morphometric modelling integrating subaerial and submarine data at the scale of a volcanic edifice. We combine field-based observations with topographic and bathymetric data analysis to reconstruct the pre- and post-eruption Digital Elevation Models (DEMs) and, comparing with present-day DEM, to analyze morphometrically the influence of volcanism on the coastal landscape's development. The resulting landform complexity required discretization of the lava field according to the coastline evolution, lava front sectors, and subaerial or submarine lava placement. We quantitatively demonstrate that dominant degradation occurs in the lava field, mainly disturbed by marine erosion (Rodriguez-Gonzalez et al., 2022, Geomorphology 416, 108427). Marine erosion removed 9 % of the erupted volume of lava flows against 1 % by fluvial erosion. This work provides methods and results of great interest with different implications in oceanic volcanic islands, among which we can mention coastal planning (e.g., rock coast evolution) and volcanic risk assessment (e.g., the importance of Holocene sea-level rise on the development of shore platforms facilitating the progradation of lava deltas).This work was supported by grant PGC2018-101027-B-I00 funded by MCIN/AEI/10.13039/501100011033 and by "ERDF A way of making Europe", by the "European Union". CPT acknowledges the PhD grant 2021 FISDU 00347 funded by the Departament de Recerca i Universitats de la Generalitat de Catalunya.Peer reviewe

Lava flow modelling at El Hierro (Canary Islands): the case of Montaña Aguarijo volcano

EGU General Assembly 2021, vEGU21: Gather Online | 19-30 April 2021Lava flow simulations are valuable tools for forecasting and assessing the areas that may be potentially affected by new eruptions, but also for interpreting past volcanic events and understanding the controls on lava flow behaviour. The plugin Q-LavHA v3.0 (Mossoux et al., 2016), integrated into QGIS, allows simulating the inundation probability of an a¿a lava flow from one or more eruptive vents spatially distributed in a Digital Elevation Model (DEM). Q-LavHA allows running probabilistic and deterministic methods to calculate the spatial propagation and the maximum length of lava flows, considering a number of morphometric and/or thermo-rheological parameters. El Hierro is the smallest and westernmost island of the Canary Archipelago where basaltic lava flows infer the major volcanic hazard. However, no lava flow emplacement modelling has been carried out yet on the island. Here we present Montaña Aguarijo's lava flow simulation, a monogenetic volcano located on the NW rift of El Hierro. Detailed geological fieldwork and current topographic-bathymetric data were used to reconstruct the pre-eruption (before the eruption modifies the relief) and post-eruption (at the end of the eruption, prior to erosive processes) DEMs. The obtained morphometric parameters of the lava flow (2,268m long; 5m medium thickness; 422,560m3) were used to run probabilistic (Maximum Length) and deterministic (FLOWGO) models. The latter also considers a set of thermo-rheological properties of the lava flow such as initial viscosity, phenocryst content, or vesicle proportion. Results obtained show a high degree of overlap between the real and simulated lava flows. Therefore, the thermo-rheological parameters considered in the deterministic approach are close to the real ones that constrained Montaña Aguarijo lava flow propagation. Moreover, this work evidence the effectiveness of Q-LavHA plugin when simulating complex lava flows such as Montaña Aguarijo¿s lava which runs through a coastal platform, a typical morphology of oceanic volcanic islands.Financial support was provided by Project LAJIAL (ref. PGC2018-101027-B-I00, MCIU/AEI/FEDER, EU). This study was carried out in the framework of the Research Consolidated Groups GEOVOL (Canary Islands Government, ULPGC) and GEOPAM (Generalitat de Catalunya, 2017 SGR 1494)

Lava deltas, a key landform in oceanic volcanic islands: El Hierro, Canary Islands

Marine and subaerial erosion of volcanic ocean islands form coastal cliffs and shore platforms, particularly during stable sea levels. Posterosional lava flows can spill over these coastal cliffs and fill the platforms, leading to the progradation of lava deltas. This work aims to analyze this volcanic rocky coast setting at the island scale and to assess the volcanic constructional and erosive degradational effects on the coast at the scale of one volcanic edifice. El Hierro Island, Canary Islands, exemplifies a rocky coast with an active sea-cliff profile, reflecting its early evolutionary stage as a young ocean volcanic island with no fringing reef. The occurrence of a contemporary insular shelf formed during the Holocene sea-level highstand (<7 ka) allows constraining the ages of those eruptions forming lava deltas affecting this geomorphological landform. A detailed bathymetry around the island allowed us to distinguish 17 eruptions fulfilling this criterion. The Montaña del Tesoro, which occurred about 1050 years BP, is one of these eruptions and was selected as a case study for morphometric modeling integrating subaerial and submarine data at the scale of a volcanic edifice. This eruption was a Strombolian basaltic volcanic event that produced a scoria cone, pyroclastic fall deposits, and lava flows that reached the ocean in the eastern rift zone of El Hierro island. We combine field-based observations with topographic and bathymetric data analysis to reconstruct the pre- and post-eruption Digital Elevation Models (DEMs) and, comparing with present-day DEM, to analyze morphometrically the influence of volcanism on the coastal landscape's development. The resulting landform complexity required the discretization of the lava field according to the coastline evolution and lava front sectors, and the subaerial or submarine lava placement. The pyroclastic materials' total erupted bulk volume (12,829,578 m3) corresponds to a volcanic eruption index (VEI) of 3. This event was primarily effusive. From a dense rock equivalent (DRE) volume of 25,615,424 m3, 87 % flowed as lava, 10 % formed the cinder cone, and 3 % the tephra fall deposits. We quantitatively demonstrate that dominant degradation occurs in the lava field, mainly disturbed by marine erosion. Marine erosion removed 9 % of the erupted volume of lava flows against 1 % by fluvial erosion. This work provides methods and results of great interest with different implications in oceanic volcanic islands, among which we can mention coastal planning (e.g., rock coast evolution) and volcanic risk assessment (e.g., the importance of Holocene sea-level rise on the development of shore platforms facilitating the progradation of lava deltas).Grant PGC2018-101027-B-I00 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”, by the “European Union”. CPT acknowledges the PhD grant 2021 FISDU 00347 funded by the Departament de Recerca i Universitats de la Generalitat de Catalunya.Peer reviewe

Volcanes en movimiento

Filename 1: Panel1-VolcanesMovimiento.pdf; Filename 2: Panel2-VolcanesMovimiento.pdf; Filename 3: Panel3-VolcanesMovimiento.pdf; Filename 4: Panel4-VolcanesMovimiento,pdf; Filename 5: Panel5-VolcanesMovimiento.pdf; Filename 6: Panel6-VolcanesMovimiento.pdf; Filename 7: Panel7-VolcanesMovimiento.pdf; Filename 8: Panel8-VolcanesMovimiento.pdf[ES] A través de una colección de ocho paneles se explica la historia geológica de la isla de El Hierro. Se contextualiza cómo se formaron y evolucionaron las Islas Canarias y se introduce el nacimiento de El Hierro. A continuación, se observan los paisajes herreños como respuesta a fenómenos de macroescala, como los deslizamientos gigantes y las dorsales (rifts), y microescala (conos, lavas e islas bajas). Se expone la última erupción de la isla que dio lugar al volcán submarino Tagoro. Finalmente, se presenta cómo los herreños se han adaptado al territorio, sabiendo aprovechar sus escasos recursos hídricos y adaptando su modo de vida al paisaje volcánico que le rodea, consiguiendo que la isla al completo haya sido declarada por la UNESCO Reserva Mundial de la Biosfera en el año 2000 y Geoparque en el año 2015.[EN] We explain the geological history of the island of El Hierro through a collection of eight panels. How the Canary Islands were formed and evolved is contextualized, and we introduce the birth of El Hierro. Next, we observe the landscapes of El Hierro as a response to macro-scale, such as giant landslides and rifts, and micro-scale phenomena (cones, lavas, and shore platforms). The last eruption of the island that gave rise to the Tagoro submarine volcano is also exposed. Finally, we present how the Herreños have adapted to the territory, knowing how to take advantage of its scarce water resources and adapt their way of life to the volcanic landscape, achieving that the entire island was declared in 2000 a UNESCO World Biosphere Reserve and Geopark in 2015.Project LAJIAL (ref. PGC2018-101027-B-I00, MCIU/AEI/FEDER, EU). Research Consolidated Groups GEOVOL (Canary Islands Government, ULPGC) and GEOPAM (Generalitat de Catalunya, 2017 SGR 1494).Filename 1: Panel1-VolcanesMovimiento.pdf; Filename 2: Panel2-VolcanesMovimiento.pdf; Filename 3: Panel3-VolcanesMovimiento.pdf; Filename 4: Panel4-VolcanesMovimiento,pdf; Filename 5: Panel5-VolcanesMovimiento.pdf; Filename 6: Panel6-VolcanesMovimiento.pdf; Filename 7: Panel7-VolcanesMovimiento.pdf; Filename 8: Panel8-VolcanesMovimiento.pdfN