Excess degassing drives long-term volcanic unrest at Nevado del Ruiz.

This study combines volcanic gas compositions, SO2 flux and satellite thermal data collected at Nevado del Ruiz between 2018 and 2021. We find the Nevado del Ruiz plume to have exhibited relatively steady, high CO2 compositions (avg. CO2/ST ratios of 5.4 ± 1.9) throughout. Our degassing models support that the CO2/ST ratio variability derives from volatile exsolution from andesitic magma stored in the 1-4 km depth range. Separate ascent of CO2-rich gas bubbles through shallow (< 1 km depth), viscous, conduit resident magma causes the observed excess degassing. We infer that degassing of ~ 974 mm3 of shallow (1-4 km) stored magma has sourced the elevated SO2 degassing recorded during 2018-2021 (average flux ~ 1548 t/d). Of this, only < 1 mm3 of magma have been erupted through dome extrusion, highlighting a large imbalance between erupted and degassed magma. Escalating deep CO2 gas flushing, combined with the disruption of passive degassing, through sudden accumulation and pressurization of bubbles due to lithostatic pressure, may accelerate volcanic unrest and eventually lead to a major eruption.

The emissions of CO2 and other volatiles from the world's subaerial volcanoes.

Volcanoes are the main pathway to the surface for volatiles that are stored within the Earth. Carbon dioxide (CO2) is of particular interest because of its potential for climate forcing. Understanding the balance of CO2 that is transferred from the Earth's surface to the Earth's interior, hinges on accurate quantification of the long-term emissions of volcanic CO2 to the atmosphere. Here we present an updated evaluation of the world's volcanic CO2 emissions that takes advantage of recent improvements in satellite-based monitoring of sulfur dioxide, the establishment of ground-based networks for semi-continuous CO2-SO2 gas sensing and a new approach to estimate key volcanic gas parameters based on magma compositions. Our results reveal a global volcanic CO2 flux of 51.3 ± 5.7 Tg CO2/y (11.7 × 1011 mol CO2/y) for non-eruptive degassing and 1.8 ± 0.9 Tg/y for eruptive degassing during the period from 2005 to 2015. While lower than recent estimates, this global volcanic flux implies that a significant proportion of the surface-derived CO2 subducted into the Earth's mantle is either stored below the arc crust, is efficiently consumed by microbial activity before entering the deeper parts of the subduction system, or becomes recycled into the deep mantle to potentially form diamonds.

Risk factors associated with late-onset neonatal sepsis / Factores de riesgo asociados a sepsis neonatal tardía

Background: Sepsis is one of the main causes of morbidity and mortality in neonates. Objective: To identify the risk factors for neonatal sepsis in a neonatal unit from March to October, 2016. Methods: Case-control study. The factors analyzed were: a) neonatal factors such as: type of delivery, sex, birth weight, gestational age, criteria for systemic inflammatory response syndrome, type of sepsis (early or late) and blood culture result; B) invasive methods such as: central catheterization, total parenteral nutrition, umbilical catheterization and mechanical ventilation; C) maternal factors such as: number of prenatal controls, infection during pregnancy, premature rupture of membranes, maternal age and maternal fever. Odds Ratio was used to determine association. Results: For the development of early-onset sepsis, significant risk factors were: thermodynamic imbalance, tachycardia and maternal fever. With regard to late-onset sepsis, significant associations were found for thermodynamic imbalance, umbilical catheterization, mechanical ventilation and insufficient prenatal care. Conclusions: Thermodynamic imbalance, tachycardia, mechanical ventilation, umbilical catheterization, maternal fever, and insufficient prenatal care were the probable risk factors associated with neonatal sepsis.

Introducción: la sepsis es una de las principales causas de morbimortalidad en neonatos. Objetivo: identificar los factores de riesgo para sepsis neonatal en una unidad de neonatología durante los meses de marzo a octubre del año 2016. Métodos: estudio de casos y controles. Los factores analizados fueron: a) factores neonatales como: tipo de parto, sexo, peso al nacimiento, edad gestacional, criterios de síndrome de respuesta inflamatoria sistémica, tipo de sepsis (temprana o tardía) y resultado de hemocultivo; b) métodos invasivos como: cateterismo central, nutrición parenteral total, cateterismo umbilical y ventilación mecánica y; c) factores maternos como: número de controles prenatales, infección durante el embarazo, ruptura prematura de membranas, edad materna y fiebre materna. Se utilizó razón de momios (RM) para determinar asociación. Resultados: para el desarrollo de sepsis temprana, los factores de riesgo significativos fueron: el desequilibrio termodinámico, la taquicardia y la fiebre materna. Respecto a la sepsis tardía se encontraron asociaciones significativas para el desequilibrio termodinámico, el uso de cateterismo umbilical, la ventilación mecánica y los controles prenatales insuficientes. Conclusión: el desequilibrio termodinámico, la taquicardia, la ventilación mecánica, el cateterismo umbilical, la fiebre materna y los controles prenatales insuficientes fueron los probables factores de riesgo significativos asociados a sepsis neonatal.