Sea level fall during glaciation stabilized atmospheric CO2 by enhanced volcanic degassing

Paleo-climate records and geodynamic modelling indicate the existence of complex interactions between glacial sea level changes, volcanic degassing and atmospheric CO2, which may have modulated the climate system’s descent into the last ice age. Between ∼85 and 70 kyr ago, during an interval of decreasing axial tilt, the orbital component in global temperature records gradually declined, while atmospheric CO2, instead of continuing its long-term correlation with Antarctic temperature, remained relatively stable. Here, based on novel global geodynamic models and the joint interpretation of paleo-proxy data as well as biogeochemical simulations, we show that a sea level fall in this interval caused enhanced pressure-release melting in the uppermost mantle, which may have induced a surge in magma and CO2 fluxes from mid-ocean ridges and oceanic hotspot volcanoes. Our results reveal a hitherto unrecognized negative feedback between glaciation and atmospheric CO2 predominantly controlled by marine volcanism on multi-millennial timescales of ∼5,000–15,000 years

Using formative research to develop a hospital-based perinatal public health intervention in the US: The Thirty Million Words Initiative Newborn Parent Education Curriculum

Parents and caregivers do not exist in a vacuum, and with regard to crafting impactful interventions, it is increasingly being recognized that there are no one-size-fits-all approaches to behavior change. Implementing research to practice is a complex endeavor and requires the adaptation of basic research findings to different cultural and environmental contexts of intended beneficiaries (Sepinwall, 2002; Weisner & Hay, 2014). The practice of formative research allows for the systematic assessment of diverse implementation contexts and provides insights into responsive adaptations of content and delivery. In this study, we detail the use of formative testing to inform the development of a curriculum designed to support the Universal Newborn Hearing Screening (UNHS): the Thirty Million Words Initiative Newborn (TMW-Newborn) Parent Education Curriculum provides caregivers of newborns with information on the UNHS and illustrates the importance of identifying if a newborn is deaf or hard of hearing (D/HH) to ensure that caregivers learn how to promote early language development. The information provided could potentially reduce lost-to-follow up (LFU) rates for newborns who may be D/HH. Using qualitative methods, we collected and responded to feedback obtained from caregivers of newborns and were able to gear content, messaging and delivery of the intervention to stakeholder needs. A subsample of participants also completed a knowledge survey testing their understanding of intervention content prior to receiving the intervention, as well as the day after. The results showed that participant scores increased significantly post-intervention

Fluxes and origin of halogenated organic trace gases from Momotombo volcano (Nicaragua)

In order to assess the contribution of quiescent degassing volcanoes to the global halo(hydro)carbon inventory, we have quantified volcanic fluxes of methyl halides (CH3Cl, CH3Br, and CH3I), ethyl halides (C2H5Cl, C2H5Br, and C2H5I), and higher chlorinated methanes (CH2Cl2, CHCl3, and CCl4). About every eight months over a 2-year period (July 2001 to July 2003), gas samples were collected and analyzed from high-temperature fumaroles (472°C–776°C) at the Nicaraguan subduction zone volcano Momotombo. Using a simultaneous record of trace and main compounds in fumarolic gases as well as SO2 fluxes of the plume, we were able to calculate halo(hydro)carbon fluxes for Momotombo and extrapolate our results to estimate halo(hydro)carbon fluxes for the whole Quaternary Nicaraguan volcanic arc and, in addition, for all volcanoes globally. The most abundant halohydrocarbon was CH3Cl with concentrations up to 19 ppmv. Further major halo(hydro)carbons were CH3Br, CH3I, CH2Cl2, CHCl3, CCl4, C2H5Cl, C2H5Br, C2H5I, and C2H3Cl with an average concentration of 0.20 to 720 ppbv. Estimated mean halo(hydro)carbon fluxes from Momotombo were in the range of 630–5000 g/yr for methyl halides, 49–260 g/yr for ethyl halides, and 2.4–24 g/yr for higher chlorinated methanes. When the results for Momotombo are scaled up to SO2 fluxes of the Nicaraguan volcanic transect, fluxes of 1.7 × 105 g/yr CH3Cl and 82 g/yr CCl4 are attained for Nicaragua. Scaled up to the estimated global SO2 flux, this translates to hypothetical global fluxes of 5.6 × 106 g/yr CH3Cl and 2.7 × 103 g/yr CCl4. These volcanic fluxes are negligible compared to global anthropogenic and natural emissions of about 3 × 1012 g/yr CH3Cl and 2 × 1010 g/yr CCl4

Acute bronchiolitis in infancy as risk factor for wheezing and reduced pulmonary function by seven years in Akershus County, Norway

BACKGROUND: Acute viral bronchiolitis is one of the most common causes of hospitalisation during infancy in our region with respiratory syncytial virus (RSV) historically being the major causative agent. Many infants with early-life RSV bronchiolitis have sustained bronchial hyperreactivity for many years after hospitalisation and the reasons for this are probably multifactorial. The principal aim of the present study was to investigate if children hospitalised for any acute viral bronchiolitis during infancy in our region, and not only those due to RSV, had more episodes of subsequent wheezing up to age seven years and reduced lung function at that age compared to children not hospitalised for acute bronchiolitis during infancy. A secondary aim was to compare the hospitalised infants with proven RSV bronchiolitis (RS+) to the hospitalised infants with non-RSV bronchiolitis (RS-) according to the same endpoints. METHODS: 57 infants hospitalised at least once with acute viral bronchiolitis during two consecutive winter seasons in 1993–1994 were examined at age seven years. An age-matched control group of 64 children, who had not been hospitalised for acute viral bronchiolitis during infancy, were recruited from a local primary school. Epidemiological and clinical data were collected retrospectively from hospital discharge records and through structured clinical interviews and physical examinations at the follow-up visit. RESULTS: The children hospitalised for bronchiolitis during infancy had decreased lung function, more often wheezing episodes, current medication and follow-up for asthma at age seven years than did the age matched controls. They also had lower average birth weight and more often first order family members with asthma. We did not find significant differences between the RSV+ and RSV- groups. CONCLUSION: Children hospitalised for early-life bronchiolitis are susceptible to recurrent wheezing and reduced pulmonary function by seven years compared to age-matched children not hospitalised for early-life bronchiolitis. We propose that prolonged bronchial hyperreactivity could follow early-life RSV negative as well as RSV positive bronchiolitis

Origin, composition and evolution of fumarolic fluids of subduction zone volcanoes in Nicaragua

During four field campaigns (2001-2003), fumarolic gases from the two Nicaraguan volcanoes Mombacho and Momotombo were repeatedly sampled with the objective of gaining a better understanding of processes occurring within their volcano-magma-systems. Mombacho is a highly dissected stratocone volcano that is generally considered extinct. The combined chemical and isotopic composition of the gases provide evidence for high-temperature conditions in the shallow subsurface. This suggests that Mombacho volcano should not be considered extinct, and could re-awaken and erupt in the future. Momotombo is an active volcano in persistent state of fumarolic activity since its last eruption in 1905 and discharges gases at high temperatures. The chemistry, isotopic compositions and trace element contents of the gases have changed considerably over the last 20 years. These changes appear to be related to degassing of different magma batches and major changes in the interaction between the magmatic and hydrothermal systems. Flux estimates for some highly volatile and potentially harmful trace elements of magmatic origin (e.g. Tl, Bi, As, Se, Sb, Hg, Cd) show that Momotombo is only a minor source of pollutants in the atmosphere

Multiparameter surveillance of Villarrica volcano

Villarrica is one of the most active volcanoes in Chile and one of the few in the world with an active lava lake within its crater. This snow-covered volcano generates frequent strombolian eruptions and lava flows and, at times, the melting of snow can cause massive lahars. The most common types of activity at Villarrica are, however, continuous degassing and high-level seismicity. In order to investigate the mechanisms driving the persistent degassing and seismic activity at the volcano, we use a multiparameter approach based on high time-resolution gas flux measurements and seismic data. The instrumentation includes 3 stationary NOVAC-type scanning Mini-DOAS spectrometers for the quantification of SO2 fluxes, installed at the volcano in March 2009, and 7 short period and broadband seismometers. This equipment complements the existing OVDAS (Observatorio Volcanológico de los Andes del Sur) volcano monitoring network. Based of the combination of gas and seismological measurements we aim at gaining insight into magmatic and volcano- tectonic processes, especially factors playing a role for the onset of volcanic unrest. Since the gas monitoring network has been installed at the volcano a correlation between SO2 emissions and seismic activity (LP events) has been recognized. We currently investigate a possible influence of regional tectonic activity on changes detected in degassing rates and seismicity, and consequently on volcanic activity

Remote sensing of thermal emission and degassing at Villarrica Volcano, Chile

ABSTRACT FINAL ID: V44C-02 Villarrica is one of the most active volcanoes in Chile and is presently characterized by activity from open continuously degassing conduit. The twohundred meter diameter crater contains a persistent lava lake which has a diameter of approximately ten meters. For the quantification of SO2 fluxes three stationary NOVAC-type scanning Mini-DOAS UV spectrometers were installed at the volcano in March 2009. To validate the ground-based gas measurements we compared them to thermal anomalies detected by the MODVOLC algorithm which is provided by the Hawai'i Institute of Geophysics and Planetology (http://modis.higp.hawaii.edu). The MODVOLC algorithm (WRIGHT et al., 2002) uses data from the space-based Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the National Aeronautics and Space Administration’s Terra and Aqua platforms and it exhibits the possibility to monitor volcanic heat sources. Although it was not intended to detect low intensity activity from open vent degassing, we find that in the case of Villarrica the detected thermal anomalies seem to originate from the heat carried by the gas phase. Additionally we have registered correlation between SO2 fluxes and thermal activity during the whole period of our ground-based gas-monitoring. Thermal anomalies detected by the MODVOLC algorithm coincide with observed periods of increased gas flux, enabling us to estimate gas fluxes indirectly from thermal data. Wright R. et al. (2002) Remote Sensing of Environment 82, 135-15

Strong variations in degassing rates at Villarrica Volcano (Southern Chile): Consequences for deep-seated processes

Villarrica is one of the most active volcanoes in Chile, has a persistent lava lake within its crater, and is presently characterized by continuous degassing and high-level seismicity. We use a multiparameter approach based on high time-resolution gas flux measurements and seismic data to characterize magmatic and tectonic processes controlling the volcanic activity. The instrumentation includes 3 ground-based NOVAC-type scanning Mini-DOAS spectrometers for the quantification of SO2 fluxes, installed at the volcano in March 2009, which are complemented with seismic data from the catalogue of the Volcanic Observatory of the Southern Andes (OVDAS in Spanish) and from the SFB 574 temporary volcanic network. During the last three years, we have detected activity variations at Villarrica occurring on several time scales, which can be related to distinct processes at depth. The monthly averages in degassing rates increased from 400 tons/d SO2 before December 2009, to about 1200 tons/d SO2 in April 2010. Superimposed on this pattern are strong pulses of seismic LP events occurring every 3 to 4 months, accompanied by peaks in degassing rates, interpreted as periodic influx of fresh magma batches to the deeper levels of the plumbing system. The degassing rates further show cyclic variations with a periodicity of 5 to 7 days. We interpret the latter variations to represent the turnover time for a conduit convection cycle of magma from a mid-crustal reservoir, where the degassing peaks correspond to the arrival of comparatively undegassed magma at shallow levels. In addition, irregular regional earthquake events are typically followed by increased degassing activity at Villarrica 2-4 days later, interpreted as due to increased bubble nucleation in the magmatic system at depth. The period of strongly increasing degassing rates between December 2009 and April 2010 encompasses the M 8.8 Maule earthquake, which occurred on February 27, 2010. However, the degassing variations show a complex pattern, including a steady increase already 3 months before the Maule earthquake. Degassing rates dropped off sharply 7 days before the earthquake, and was followed by several weeks of comparatively low degassing during the aftershock phase. At the end of March, degassing rates picked up to a factor of 3 above the pre-earthquake level culminating with a peak of 2800 tons/d SO2 at the beginning of April. The persistence of high degassing rates even two years later indicates a permanent change in the magma plumbing system. Further, the observation that the Maule earthquake rather interrupted than enhanced the trend of increased degassing requires a fundamental increase in the magma supply to Villarrica commencing months before the rupture event. We tentatively assign the increased availability of magma to pre-rupture creep in the lower crust or at mantle depths, enabling a pressure gradient for influx of magma. We suggest that such a change in the volume of incoming magma would probably have led to an eruptive cycle at a closed vent system like e.g. the neighboring Llaima volcano