Development and recent activity of the San Andrés landslide on El Hierro, Canary Islands, Spain

Extremely voluminous landslides with a long run-out (also known as megalandslides) on oceanic volcanic islands are infrequent denudational processes on such islands. At the same time, they represent a major geological hazard that must be looked into to avoid negative consequences for the inhabitants of these islands. Their occurrence can be related to periods of intense seismo-volcanic activity, similar to that which occurred on El Hierro Island over 2011-2012. Landslides on volcanic islands are studied using onshore and offshore geological, geophysical and geomorphological records, considering their unique triggering conditions (e.g. lava intrusions, eruptive vents, magma chamber collapses). Previous work has pointed out similarities between specific cases of landslides on volcanic islands and deep-seated gravitational slope deformations (DSGSDs) which are typical in high mountain settings. Nevertheless, the methodological approaches and concepts used to investigate DSGSDs are not commonly applied on volcanic islands studies, even though their use may provide new information about the development stage, recent movements and future hazards. Therefore, this approach for studying the San Andrés landslide (SAL) on El Hierro (Canary Islands) has been developed applying a detailed morphological field mapping, an interpretation of digital elevation models, structural measurements, kinematic testing, and a precise movement monitoring system. The acquired information revealed a strong structural influence on the landslide morphology and the presence of sets of weakened planes acting as the sliding surfaces of the SAL or secondary landslides within its body. The presence of secondary landslides, deep erosive gullies, coastal cliffs and high on-shore relative relief also suggests a high susceptibility to future landslide movement. Direct monitoring on the landslide scarps and the slip plane, performed between February 2013 and July 2014, using an automated optical-mechanical crack gauge with a precision of up to 10-2 mm, detected creep movement in the order of 1 mm yr-1 with a persistent sinistral component as well as episodic horizontal and a subtle vertical movement. This monitoring will continue in the future in order to verify the initial observations, which instead of long-term movement patterns, could represent a landslide response to the period of an intense seismo-volcanic activity during 2011-12.The authors would like to thank the National Geographic Society/Waitt Grants Program (No. W244-12) and CzechGeo/EPOS (Project No. LM2010008) for the financial support of the research. We also thank the Spanish National Geographical Institute and the El Hierro Island Authority whose personnel provided us with useful support during the field installation of the measuring instruments. This work was carried out thanks to the unconditional support of the long-term conceptual development research organisation RVO: 67985891.Peer reviewe

Long-term volcanic hazard assessment on El Hierro (Canary Islands)

Long-term hazard assessment, one of the bastions of risk-mitigation programs, is required for land-use planning and for developing emergency plans. To ensure quality and representative results, long-term volcanic hazard assessment requires several sequential steps to be completed, which include the compilation of geological and volcanological information, the characterisation of past eruptions, spatial and temporal probabilistic studies, and the simulation of different eruptive scenarios. Despite being a densely populated active volcanic region that receives millions of visitors per year, no systematic hazard assessment has ever been conducted on the Canary Islands. In this paper we focus our attention on El Hierro, the youngest of the Canary Islands and the most recently affected by an eruption. We analyse the past eruptive activity to determine the spatial and temporal probability, and likely style of a future eruption on the island, i.e. the where, when and how. By studying the past eruptive behaviour of the island and assuming that future eruptive patterns will be similar, we aim to identify the most likely volcanic scenarios and corresponding hazards, which include lava flows, pyroclastic fallout and pyroclastic density currents (PDCs). Finally, we estimate their probability of occurrence. The end result, through the combination of the most probable scenarios (lava flows, pyroclastic density currents and ashfall), is the first qualitative integrated volcanic hazard map of the island.This research was partially funded by IGME, CSIC and the European Commission (FT7 Theme: ENV.2011.1.3.3-1; Grant 282759: “VUELCO”), and MINECO grant CGL2011-16144-E.Peer reviewe

AGEO : Natural hazard prevention and awareness raising through citizen observatories

ABSTRACT:The Platform for Atlantic Geohazard Risk Management (AGEO) is a new project co-financed under the Interreg Programme for the Atlantic Area which aims to launch five Citizens’ Observatory pilots on geohazards according to regional priorities.info:eu-repo/semantics/publishedVersio

The HIRES-SOM Project: Soil organic matter and microbial communities in volcanic materials from La Palma Island assessed by high-resolution techniques: implications for pedogenesis and sustainability

Comunicación oral presentada en el 1st European Meeting on Geomicrobiology of volcanic caves. días 2-3 de marzo de 2023 celebrado en la Casa de la Ciencia-CSIC de SevillaThe HIRES-SOM project is a multidisciplinary project funded by the Ministry of Science and Innovation of Spain, aimed at generating knowledge on soil organic matter (SOM) and microbiota to guide novel strategies for the sustainable management of volcanic soils. The investigation will be conducted within the framework of the recent Tajogaite eruption in La Palma Island, which constitutes an optimal benchmark both for scientific research on freshly erupted materials and for the management of affected soils of high added value. Insights into the generation and resilience of SOM and of the associated microbiota will be explored with advanced biogeochemical, microbiological, mineralogy and modelling techniques [1,2]. The main goals of the project are twofold. On the one hand, it intends to assess the state and evolution of the SOM and microbiota in soils calcined by the lava flows and covered by the pyroclastic ashes. On the other hand, fundamental understanding will be sought about the initial stages of pedogenesis and consolidation of organic matter on the eruptive materials. The project intends to identify primary microbial communities and molecular precursors of organic matter in volcanic ash, lava flows and eruption-affected soils. Moreover, accelerated microbial colonization of volcanic substrates under laboratory conditions will allow monitoring photoautotrophic microorganisms that colonize natural volcanic materials, with the ultimate innovative goal of devising methods for the rapid fertilization of porous pyroclastic ashes by indigenous microorganisms for sustainable soil regeneration. References: [1] Martinez-Haya et al, Energy Fuels 35 (2021) 8699; Talanta 185 (2018) 299; Phys. Chem. Chem. Phys. 22 (2020) 19725. [2] Miller A., et al, Sci Total Environ 426 (2012) 1; Geomicrobiol. J. 31 (2014) 236; Sedimentology 65 (2018) 1482; Sci Total Environ 698 (2020) 134321; Coatings 10 (2020) 1134.The HIRES-SOM project is funded by the Ecological and Digital Transition Programme of the Ministry of Science and Innovation of Spain (grants TED2021-130683B-C21/C22).N

Field deployment of a man-portable stand-off laser-induced breakdown spectrometer: A preliminary report on the expedition to the Cumbre Vieja volcano (La Palma, Spain, 2021)

This paper reports on the expedition to the Cumbre Vieja volcano (Canary Islands, Spain) in November 2021 to assess stand-off laser-induced breakdown spectroscopy for real-time measurements of the lava streams from a safe point. The paper provides insight on the analytical approach to the problem, the rationale of the instrument design and construction carried out in three weeks, the experience with the new-born instrument at the volcano and the preliminary results. Despite the subtle spectral differences among the samples and the signal variability induced by the strong wind gusts at site, a statistical approach to data processing such as PCA, made possible to extract sufficient information and provide a robust classification tool.We express our sincere gratitude to the Spanish Unidad Militar de Emergencias (UME) for providing essential support, security, and expertise at the field. We would like to thank Carlos Malag ́on (Astro- shop, M ́alaga, Spain) for donating the telescope used in the stand-off LIBS instrument, to the personnel of the Chemical Analysis Area and the Machine Shop of the Central Facility for Research Support (SCAI-UMA) and to Profs. E.R. Losilla and A. Cabeza (Dept. Química Inorgánica, Cristalografía y Mineralogía, UMA) and D. Marrero (Dept. Física Aplicada I, UMA) for their valuable comments and advice with the surrogate samples. This work has been partially supported by the I Plan Propio de Investigaci ́on de la Universidad de M ́alaga, the Extraordinary Funding (RD 1078/2021, 7th December, Núm. 293 Sec. I. P ́ag. 150,995) and PID2020-113407RB-I00 granted by the Spanish Ministry of Science and Innovation (MICINN). Funding for open access charge: Universidad de Málaga / CBU

Historia geológica y reconstrucción paleobiológica de los depósitos paleontológicos de la playa de El Confital (Gran Canaria, islas Canarias)

XXXIV Jornadas de Paleontología y IV Congreso Ibérico de Paleontología (Vila Real, Portugal. Sep 2018) p. 491-499El archipiélago canario está situado cerca de la costa NO de África y es de naturaleza volcánica. Fuerteventura y Lanzarote son las islas más antiguas del archipiélago (23 y 15 Ma aproximadamente) seguidas por Gran Canaria (14 Ma), siendo en estas tres islas solamente donde vamos a encontrar depósitos fosilíferos pertenecientes a las series Mioceno y Plioceno (Meco et al., 2015). El episodio MIS5e (Eemiense), por el contrario, podemos encontrarlo en todas las islas (Meco et al., 2002; Zazo et al., 2003; Martín-González et al., 2016). Este trabajo se centra en el estudio de los depósitos fosilíferos asociados a ambos periodos que aparecen en la playa de El Confital, en la isla de Gran Canaria Los afloramientos se encuentran al suroeste de La Isleta, un islote eminentemente volcánico situado en el extremo NE de Las Palmas de Gran Canaria unido al edificio insular principal por un tómbolo de arena, el istmo de Guanarteme. Se trata de una plataforma litoral activa modelada sobre piroclastos de origen hidromagmático (Hansen, 2008), que ha sido alterada antrópicamente en tiempos recientes. Las Palmas de Gran Canaria constituye uno de los escasos ejemplos en los que se pueden observar yacimientos paleontológicos de diferentes edades. En la parte alta de la ciudad se encuentra la Formación Detrítica de Las Palmas, de edad Mio-Plioceno, que contiene una importante asociación fosilífera estudiada por diferentes autores (Rothpletz & Simonelli, 1890; Meco et al., 2007; Betancort, 2012; Martín-González et al., 2018); mientras que en la zona baja se encuentran los afloramientos pertenecientes al episodio transgresivo marino MIS5e (Meco et al., 2002). En la playa de El Confital podemos encontrar, en ambos extremos, los yacimientos del Eemiense, al sur, cuyo estudio paleontológico y estratigráfico preliminar fue realizado por Cabrera (1987) y del Mioceno, al noroeste, donde Meco et al. (2015) citan por primera vez la existencia del nivel con Ostrea offretti Linnaeus. En este trabajo realizamos un análisis volcano-estratigráfico y paleontológico integral de la playa de El Confital con el fin de reconstruir la evolución temporal de la fauna fosilizada en esta zona.Museo de Ciencias Naturales (MCN). OAMCÁrea de Paleontología, Facultad de Biología, Universidad de La LagunaDpto. de Geologia, Faculdade de Ciências, Universidade de LisboaCIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Pólo dos AçoresInstituto Dom Luiz, Faculdade de Ciências da Universidade de LisboaUnidad Territorial de Canarias, Instituto Geológico y Minero de España (IGME)IOCAG. Instituto de Oceanografía y Cambio Global. Universidad de Las Palmas de Gran CanariaTELLUS. Arqueología y Prehistoria en el Sur de Iberia. HUM-949Department of Geosciences, Williams CollegeDpto. de Geografía. Universidad de La LagunaÁrea de Patrimonio Geológico y Minero, Instituto Geológico y Minero de España (IGME).Área de Geología. Universidad Rey Juan Carlo

Actualización del Mapa del Cuaternario de España (E. 1:1.000.000) y contribución española al “International Quaternary Map Of Europe (E. 1:2.500.000)”

En: Una visión global del Cuaternario. El hombre como condicionante de procesos geológicos (J. P. Galve, J. M. Azañón, J. V. Pérez Peña y P. Ruano, Eds.), pp. 113-116. XIV Reunión Nacional de Cuaternario, Granada (España)This contribution deals about a new project started by the Geological and Mining Institute of Spain with a dual purpose. First, to update the geological data of the Quaternary Map of Spain at 1:1,000,000 scale, and also to update its format and data model. Second, to contribute with cartographic data about the Quaternary geology at 1: 2,500,000 of the Spanish european territory (Iberian Peninsula and Balearic Islands) for carrying out a new digital version of the International Quaternary Map of Europe (IQUAME-2500), an international project based on a multi-institutional collaborative framework. In order to achieve these goals, multiple factors shall be taken into account such as the diverse scientific-technical requirements, the sources of the key data, the different tasks to be performed and the potential synergies with other data sets about Quaternary geology.Instituto Geológico y Minero de España (IGME)Peer reviewe

Radon (222Rn) outgassing in San Juan volcanic tubes during the Cumbre Vieja eruption 2021, and preliminary values in the new volcanic tubes

Comunicación oral presentada en el 1st European Meeting on Geomicrobiology of volcanic caves. días 2-3 de marzo de 2023 celebrado en la Casa de la Ciencia-CSIC de SevillaDuring the eruption at Cumbre Vieja ridge (La Palma, Canary Islands, 2021) a radon (222Rn) detector (CORENTIUM Pro alpha particles counter) was emplaced inside the “Las Palomas” lava tube (San Juan eruption, 1949). In addition, a CO2 meter logger was emplaced to determine relationships between the 2021 eruption and radon plus CO2 inner fluxes. There is a geostructural relationship between the 1949 and 2021 eruptions, probably connected by a previous fault, shown the volcanic vents’ alignment trending NW-SE. In October 2021, the radon and CO2 loggers were moved to the upper part of the lava tube, in the San Juan volcanic vent (Llano del Banco hollow dyke). Once the eruption ended (in early 2022) both loggers were placed in one newly formed lava tube, and data will be collected in February 2023. Preliminary results show daily average radon values ranging between 2 - 9 Bq/m3, although sporadic peaks of about 270 and 650 Bq/m3 were recorded related to volcano-tectonic earthquakes and volcanic intensity. In general, basaltic eruptions of alkaline affinity show low radon values due to the low concentration in the magma body of uranium and related chemical elements (Th, Ra, etc.). Geochemical analysis of emitted lavas shows a U concentration of about 1 to 5 ppm (μg/g) and Th 9.5 ppm. Summer values of Rn increased up to 3 KBq/m3, related to the climate conditions instead of volcanic activity.This study was funded by the project CSIC 20223PAL002 “Investigación Geológica de la Erupción de 2021 en Cumbre Vieja” and partially by the project FAMRAD (PID2020-113407RB-I00): Geochemical modeling of seismic prediction from endogenous gas emission (222Rn, CO2, CH4), and earthquakes by using radioactive caves and boreholes in the Alhama de Murcia fault.N

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Basaltic feeder dykes in rift zones: geometry, emplacement and effusion rates

Most volcanic hazards depend on an injected dyke reaching the surface to form a feeder. Assessing the volcanic hazard in an area is thus related to understanding the condition for the formation of a feeder dyke in that area. For this latter, we need good field data on feeder dykes, their geometries, internal structures, and other characteristics that distinguish them from non-feeders. Unfortunately, feeder dykes are rarely observed, partly because they are commonly covered by their own products. For this reason, outcrops are scarce and usually restricted to cliffs, ravines, and man-made outcrops. Here we report the results of a study of feeder dykes in Tenerife (Canary Islands, Spain) and Iceland, focusing on their field characteristics and how their propagation is affected by existing structures. Although Holocene fissure eruptions have been common in both islands, only eleven basaltic feeder dykes have been identified: eight in Tenerife and three in Iceland. They are all well preserved and the relation with the eruptive fissure and/or the deposits is well exposed. While the eruptive fissures are generally longer in Iceland than in Tenerife, their feeders show many similarities, the main ones being that the feeder dykes (1) are generally sheet-shaped; (2) are segmented (as are the associated volcanic fissures); (3) normally contain elongated (prolate ellipsoidal) cavities in their central, topmost parts, that is, 2–3 m below the surface (with solidified magma drops on the cavity walls); (4) contain vesicles which increase in size and number close to the surface; (5) sometimes inject oblique dyke fingers into the planes of existing faults that cross the dyke paths; and (6) may reactivate, that is, trigger slip on existing faults. We analyse theoretically the feeder dyke of the 1991 Hekla eruption in Iceland. Our results indicate that during the initial peak in the effusion rate the opening (aperture) of the feeder dyke was as wide as 0.77 m, but quickly decreased to about 0.56 m. During the subsequent decline in the effusion rate to a minimum, the aperture decreased to about 0.19 m. At a later abrupt increase in the effusion rate, the feeder-dyke opening may have increased to about 0.34 m, and then decreased again as the effusion rate gradually declined during the end stages of the eruption. These thickness estimates fit well with those of many feeders in Iceland and Tenerife, and with the general dyke thickness within fossil central volcanoes in Iceland.Unidad de las Islas Canarias, Instituto Geológico y Minero de España, EspañaDepartment of Earth Sciences, University of London, Reino Unid