Evaluación de peligros de los volcanes Descabezado Grande, Quizapu, Cerro Azul y Centros Eruptivos Aledaños (Chile): resultados preliminares

Los volcanes Descabezado Grande, Quizapu y Cerro Azul (Figura 1) forman parte de una agrupación de al menos 18 centros de emisión que se ubican en la parte septentrional de la Zona Volcánica Sur de los Andes (ZVS), específicamente en el sector cordillerano de la Región del Maule, Chile (35°14'-35°49' S; 71°11'-70°35' O; Figura 2). Se incluyen en esta área los centros eruptivos menores Las Resolanas, Los Hornitos, Cerro Colorado, Reformados, Mondaca y Alto Las Mulas, todos ellos con actividad conocida o probable durante el periodo postglacial (para efectos de este trabajo <20.000 años AP). Sus características morfológicas varían entre estratovolcanes, conos piroclásticos, maares, domos y coladas de lava; los que se concentran en un área de 15x30 km. Dentro de la actividad eruptiva histórica de la zona de estudio, destacan dos de las erupciones de mayor magnitud en la historia reciente de los Andes, ambas ocurridas en el volcán Quizapu, en los años 1846-48 y 1932, las que en conjunto emitieron alrededor de 10 km3 de magma a la superficie (Hildreth y Drake, 1992). Este grupo de volcanes se localiza en la Cordillera Principal de una de las regiones con mayor cantidad de habitantes de Chile (1.153.043 hab.; INE, 2017; Figura 2), por lo que presenta una particular relevancia en términos político-administrativos y económicos, concentrando una importante porción de la actividad silvoagropecuaria y de generación eléctrica del país. En consecuencia, la exposición en la región en conjunto con la alta productividad magmática reciente, hacen que esta zona sea prioritaria dentro de las acciones en el contexto de la reducción del riesgo de desastres volcánicos a nivel nacional. Este trabajo tiene como objetivo evaluar los peligros de los volcanes antes mencionados, con la finalidad de zonificar el peligro asociado y generar información cartográfica a escala 1:75.000, para ser utilizada en el contexto de la gestión del riesgo. Adicionalmente, se presentan nuevas evidencias de la actividad explosiva postglacial de los sistemas volcánicos en estudio, mejorando el conocimiento respecto a su recurrencia eruptiva, magnitudes y posibles impactos. Dicho esto, la estructura del presente resumen comienza con una descripción de los centros eruptivos, la identificación de los procesos evaluados de acuerdo al registro geológico, una descripción general de la actividad histórica, un resumen de la metodología y resultados preliminares de la evaluación de peligros, los alcances y conclusiones

Efecto de un método de Entrenamiento Intervalado de Alta Intensidad sobre el consumo máximo de oxígeno en escolares chilenos

Introduction: The low levels of maximum oxygen consumption (VO2max) evaluated in Chilean schoolchildren suggest the startup of trainings that improve the aerobic capacity. Objective: To analyze the effect of a High-intensity Interval Training method on maximum oxygen consumption in Chilean schoolchildren. Materials and methods: Thirty-two high school students from the eighth grade, who were divided into two groups, were part of the study (experimental group = 16 students and control group = 16 students). The main analyzed variable was the maximum oxygen consumption through the Course Navette Test. A High-intensity Interval training method was applied based on the maximum aerobic speed obtained through the Test. A mixed ANOVA was used for statistical analysis. Results: The experimental group showed a significant increase in the Maximum Oxygen Consumption between the pretest and posttest when compared with the control group (p < 0.0001). Conclusion: The results of the study showed a positive effect of the High-intensity Interval Training on the maximum consumption of oxygen. At the end of the study, it is concluded that High-intensity Interval Training is a good stimulation methodology for Chilean schoolchildren

Unrest at the Nevados de Chillán volcanic complex: a failed or yet to unfold magmatic eruption?

Resuming erupting activity at volcanoes that have been long quiescent poses a significant challenge to hazard assessment, as it require assessment of whether the change in activity is an isolated event or the beginning of a new eruptive sequence. Such inception is often poorly characterised as quiescent volcanoes tend to be poorly equipped and not extensively monitored, especially with respect to gas geochemistry. Here, we report gas composition and flux measurements from a newly opened vent at the very onset of eruptive activity at the Nevados de Chillán volcanic complex (Chile) in January-February 2016. The molar proportions of H2O, CO2, SO2, H2S and H2 gases are found to be 98.4, 0.97, 0.11, 0.01 and 0.5 mol% respectively. The mean SO2 flux recorded in early February 2016 during periods of eruptive discharge amounts to 0.4-0.6 kg s-1. Our results indicate that the new vent opening was propelled by magmatic gases, triggering repeated eruptions. Ash particles ejected by the first blast of 8 January are dominated by lithic fragments of dacitic composition. By contrast the ash ejected in a subsequent eruption contains both lithic fragments of dense dacite, and a fresher, sparsely vesicular material of basaltic andesite composition. By October 2017 the ejected ash is back to being dominated by the dense dacitic lithic material. Together with the seismic and deformation record, these observations point to the explosive activity resulting from a small intrusion of basaltic to andesitic magma at shallow level. The fate of this magma, whether stalling or eventually triggering a magmatic eruption, remains to be seen, but current observations suggest the former is most likely

Mapa regional y ranking de riesgos volcánicos de la zona volcánica central de los Andes

La Zona Volcánica Central de los Andes (ZVCA) es una de las zonas volcánicas más activas de América del Sur y es una de las áreas en las que la mayoría de los volcanes se encuentran dentro de los 25 km de una frontera internacional comprendiendo Argentina, Chile, Bolivia y Perú, con importantes desafíos transfronterizos (Donovan & Oppenheimer, 2019). En esta región, los volcanes se ubican en el Altiplano-Puna (sobre los 4000 m de altitud) y, por lo tanto, varios volcanes superan los 6000 m s.n.m., entre ellos el Ojos del Salado que es la cumbre volcánica más alta del mundo. Durante décadas, la ZVCA ha sido un sitio importante para entender una gran cantidad de procesos geológicos (e.g, evolución geológica, tectónica, espesor de la corteza, erosión y geometría por subducción, segmentación del arco volcánico y génesis del magma), pero debido al difícil acceso, los registros de erupciones eran bastante escasos, hasta hace muy poco. Durante los últimos 20 años, la agitación volcánica en varias partes de la ZVCA ha permitido la implementación de nuevas capacidades de monitoreo e inversiones en investigación (Aguilera et al., 2022) y como consecuencia, se ha puesto a disposición nueva información detallada. La priorización de estrategias de reducción de riesgos es especialmente importante para la ZVCA debido a su gran cantidad de volcanes. Además, el número de personas expuestas a la actividad volcánica en la ZVCA depende de la dinámica eruptiva y la magnitud de las erupciones potenciales

CSVS, a crowdsourcing database of the Spanish population genetic variability

The knowledge of the genetic variability of the local population is of utmost importance in personalized medicine and has been revealed as a critical factor for the discovery of new disease variants. Here, we present the Collaborative Spanish Variability Server (CSVS), which currently contains more than 2000 genomes and exomes of unrelated Spanish individuals. This database has been generated in a collaborative crowdsourcing effort collecting sequencing data produced by local genomic projects and for other purposes. Sequences have been grouped by ICD10 upper categories. A web interface allows querying the database removing one or more ICD10 categories. In this way, aggregated counts of allele frequencies of the pseudo-control Spanish population can be obtained for diseases belonging to the category removed. Interestingly, in addition to pseudo-control studies, some population studies can be made, as, for example, prevalence of pharmacogenomic variants, etc. In addition, this genomic data has been used to define the first Spanish Genome Reference Panel (SGRP1.0) for imputation. This is the first local repository of variability entirely produced by a crowdsourcing effort and constitutes an example for future initiatives to characterize local variabilityworldwide. CSVS is also part of the GA4GH Beacon network.Spanish Ministry of Economy and Competitiveness SAF2017-88908-R PT17/0009/0006 PI19/00321 CIBERER ACCI-06/07/0036 PI14-948 PI171659Regional Government of Madrid, RAREGenomicsCM B2017/BMD3721 B2017/BMD-3721European Union (EU)European Union (EU) 676559University Chair UAM-IIS-FJD of Genomic MedicineRamon Areces Foundatio

Healthcare workers hospitalized due to COVID-19 have no higher risk of death than general population. Data from the Spanish SEMI-COVID-19 Registry

Aim To determine whether healthcare workers (HCW) hospitalized in Spain due to COVID-19 have a worse prognosis than non-healthcare workers (NHCW). Methods Observational cohort study based on the SEMI-COVID-19 Registry, a nationwide registry that collects sociodemographic, clinical, laboratory, and treatment data on patients hospitalised with COVID-19 in Spain. Patients aged 20-65 years were selected. A multivariate logistic regression model was performed to identify factors associated with mortality. Results As of 22 May 2020, 4393 patients were included, of whom 419 (9.5%) were HCW. Median (interquartile range) age of HCW was 52 (15) years and 62.4% were women. Prevalence of comorbidities and severe radiological findings upon admission were less frequent in HCW. There were no difference in need of respiratory support and admission to intensive care unit, but occurrence of sepsis and in-hospital mortality was lower in HCW (1.7% vs. 3.9%; p = 0.024 and 0.7% vs. 4.8%; p<0.001 respectively). Age, male sex and comorbidity, were independently associated with higher in-hospital mortality and healthcare working with lower mortality (OR 0.211, 95%CI 0.067-0.667, p = 0.008). 30-days survival was higher in HCW (0.968 vs. 0.851 p<0.001). Conclusions Hospitalized COVID-19 HCW had fewer comorbidities and a better prognosis than NHCW. Our results suggest that professional exposure to COVID-19 in HCW does not carry more clinical severity nor mortality

Modeling pyroclast transport and sedimentation in the Andean central and southern volcanic zones

This thesis examines patterns of pyroclastic dispersal and sedimentation from active volcanoes located in the Andean Central and Southern volcanic zones. Numerical approaches are utilized, including single-particle trajectories, advection-diffusion and particle-tracking models, in order to gain insights into the impact of future volcanic eruptions in the region. Numerical models and wind data have been tested considering recent eruptions that have occurred in the Andes, and both tephra dispersal and recorded fallout have been successfully rebuilt. As volcanic zones are separated by several degrees of latitude, different environmental conditions are observed. For the Central Volcanic Zone interseasonal variability is present, and even opposite transport directions are observed between austral summer and winter months. Interannual variability is also detected, being mostly related to the El Nifio Southern Oscillation in the troposphere, and to the Quasi-Biennal Oscillation in the stratosphere. Outcomes from the modeling indicate that distal regions from the volcanic sources are likely to be impacted for tephra fallout, in particular when westward transport occurs during the summer (northern segment) or when eastward transport is intensified during winter (southern segment) . In contrast is the southernmost Southern Volcanic Zone where eastward transport is dominant throughout the year. Pyroclast dispersal is more widespread during the autumn-winter period, in connection with the arrival of frontal systems. Differences in atmospheric circulation between the upper troposphere and lower stratosphere are less evident at these latitudes. Probabilistic maps of tephra accumulation on the surface, derived for different eruptive scenarios, have been outlined for areas close to active volcanoes. Additionally, exceedance probability curves were estimated for places of interest. Volcanoes analyzed include El Misti in southern Peru, Parinacota in the Chile-Bolivia border and Lascar in northern Chile, which are located in the Central Volcanic Zone. Hudson volcano was selected from the Southern Volcanic Zone. Volcanic hazard implications are discussed for all case studies. In addition, pyroclastic transport and dispersal have also been addressed in some cases. Lahar flows were numerically simulated for Hudson volcano, and an estimation of the probability of occurrence of a moderate to high magnitude eruption was calculated. Some topics of the methodology are briefly discussed, including the importance of shape factor of particles on settling velocity. A sensitivity analysis of the estimated probability of tephra accumlation on the surface to the total number of simulations was investigated.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Modeling pyroclast transport and sedimentation in the Andean central and southern volcanic zones

This thesis examines patterns of pyroclastic dispersal and sedimentation from active volcanoes located in the Andean Central and Southern volcanic zones. Numerical approaches are utilized, including single-particle trajectories, advection-diffusion and particle-tracking models, in order to gain insights into the impact of future volcanic eruptions in the region. Numerical models and wind data have been tested considering recent eruptions that have occurred in the Andes, and both tephra dispersal and recorded fallout have been successfully rebuilt. As volcanic zones are separated by several degrees of latitude, different environmental conditions are observed. For the Central Volcanic Zone interseasonal variability is present, and even opposite transport directions are observed between austral summer and winter months. Interannual variability is also detected, being mostly related to the El Nifio Southern Oscillation in the troposphere, and to the Quasi-Biennal Oscillation in the stratosphere. Outcomes from the modeling indicate that distal regions from the volcanic sources are likely to be impacted for tephra fallout, in particular when westward transport occurs during the summer (northern segment) or when eastward transport is intensified during winter (southern segment) . In contrast is the southernmost Southern Volcanic Zone where eastward transport is dominant throughout the year. Pyroclast dispersal is more widespread during the autumn-winter period, in connection with the arrival of frontal systems. Differences in atmospheric circulation between the upper troposphere and lower stratosphere are less evident at these latitudes. Probabilistic maps of tephra accumulation on the surface, derived for different eruptive scenarios, have been outlined for areas close to active volcanoes. Additionally, exceedance probability curves were estimated for places of interest. Volcanoes analyzed include El Misti in southern Peru, Parinacota in the Chile-Bolivia border and Lascar in northern Chile, which are located in the Central Volcanic Zone. Hudson volcano was selected from the Southern Volcanic Zone. Volcanic hazard implications are discussed for all case studies. In addition, pyroclastic transport and dispersal have also been addressed in some cases. Lahar flows were numerically simulated for Hudson volcano, and an estimation of the probability of occurrence of a moderate to high magnitude eruption was calculated. Some topics of the methodology are briefly discussed, including the importance of shape factor of particles on settling velocity. A sensitivity analysis of the estimated probability of tephra accumlation on the surface to the total number of simulations was investigated.EThOS - Electronic Theses Online ServiceGBUnited Kingdo