Effects of the lava flows associated to the Tajogaite volcano eruption (2021) on the insular shelf and slope of La Palma island
The eruption of the Cumbre Vieja volcano started on September 19, 2021, on the island of La Palma, following a seismic swarm that affected the southern half of the island. The lava flowed westward and reached the coastline 8 days later in the area between Punta de la Bombilla and Tazacorte harbour....
| Autores: | , , , , , , , , , , , , , |
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| Tipo de recurso: | otro |
| Fecha de publicación: | 2023 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/332045 |
| Acceso en línea: | http://hdl.handle.net/10261/332045 |
| Access Level: | acceso abierto |
| Palabra clave: | Erupción volcánica Coladas de lava Batimetría Lavas aa Mega-pillow Hialoclastita Anomalía físico química |
| Sumario: | The eruption of the Cumbre Vieja volcano started on September 19, 2021, on the island of La Palma, following a seismic swarm that affected the southern half of the island. The lava flowed westward and reached the coastline 8 days later in the area between Punta de la Bombilla and Tazacorte harbour. Four oceanographic cruises on board the research vessels Ramón Margalef and Ángeles Alvariño (Spanish Institute of Oceanography, IEO-CSIC) aimed to (i) characterizing the petrologic features prior to the arrival of the lava flows into the coastline, (ii) assessing the variations of the water-magma system when the lava flowed into the sea, and (iii) evaluating the main changes in the system after the end of the eruption. High-resolution bathymetric maps obtained with the multibeam echosounder EM710, combined with submarine high- definition ROV LIROPUS images and rocks samples collected from the sea bottom, showed that lava flowed down the shelf and upper slope as block (aa) and pillow lava flows, being conditioned by small gullies on the upper slope. Significant morphological changes have been defined in the subaerial northern and southern lava deltas (areas of 5,4 and 43 ha, respectively), and on a submarine area of ~30 ha. Volcanic material has been identified as far as 1.2 km from the original coastline at ~305 m seawater depth. Preliminary petrographic studies determine that the began as tephrites and later evolved intro basanites with olivine, pyroxene, amphibole and plagioclase phenocrysts within a glassy matrix with variable number of vesicles. The total volume of lava reaching the submarine environment is estimated of around 3 Mm3 with maximum thickness ca. 40 m along previous submarine slope gullies. Integrated with multidisciplinary analyses of the water column and ecosystem changes, this study will improve the knowledge of the magmatic evolution from depth up to eruption and will be useful for the risk management of future eruptive events. |
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