Emission of trace halogens (Br, I) from a basaltic volcano: Mount Etna

First record of the alien leech Myzobdella lugubris Leidy, 1851 (Hirudinea, Piscicolidae) in the Palearctic

espanolEn este estudio reportamos la aparicion de la sanguijuela Neartica Myzobdella lugubris en un cuerpo de agua salobre de la reserva natural Riserva Naturale dello Stato “Le Cesine” (Apulia, Italy). Dos especimenes de la especie fueren recolectados en el cuello y las extremidades anteriores de una tortuga de estanque europea Emys orbicularis hellenica en Octubre del 2016. La identificacion de los dos especimenes fue basada en datos morfologicos y de secuenciacion molecular. En su distribucion natural, M. lugubris es conocida por ser huesped y vector de bacterias y virus, de los cuales algunos son patogenos de gravedad en peces. En vista de los posibles efectos nocivos, que ejercen sobre…

New molecular data attest to the absence of cospeciation patterns between Placobdella costata (Fr. Müller, 1846) (Hirudinea) and freshwater turtles (Emys spp.) in Italy

The only Palearctic representative of the leech genus Placobdella Blanchard, 1893 is P. costata, an ectoparasite of freshwater turtles. To date, no conclusive evidence about the possible presence of coevolutionary patterns between this leech and its turtle hosts is available due to the paucity of DNA sequence data available for P. costata; moreover, comparative host data is also mostly lacking, making any inferences more difficult. The discovery of new populations of the species in northern Italy and Sicily allowed us to generate novel mitochondrial DNA sequences and to compare the topology of the resulting phylogenetic trees with the phylogeny of the turtle hosts occurring in the study are…

Chemical variability in volcanic gas plumes and fumaroles along the East African Rift System: New insights from the Western Branch

The origin of magmatic fluids along the East African Rift System (EARS) is a long-lived field of debate in the scientific community. Here, we investigate the chemical composition of the volcanic gas plume and fumaroles at Nyiragongo and Nyamulagira (Democratic Republic of Congo), the only two currently erupting volcanoes set on the Western Branch of the rift. Our results are in line with earlier conceptual models proposing that volcanic gas emissions along the EARS mainly reflect variable contributions of either a Sub-Continental Lithospheric Mantle (SCLM) component or a Depleted Morb Mantle (DMM) component, and deeper fluid. At Nyiragongo and Nyamulagira, our study discards a major contrib…

Unusually large magmatic CO2 gas emissions prior to a basaltic paroxysm

The low-intensity activity of basaltic volcanoes is occasionally interrupted by short-lived but energetic explosions which, whilst frequently observed, are amongst the most enigmatic volcanic events in Nature. The combination of poorly understood and deep, challenging to measure, source processes make such events currently impossible to forecast. Here we report increases in quiescent degassing CO2 emissions (>10,000 t/day) prior to a powerful explosive event on Stromboli volcano on 15 March 2007. We interpret such large CO2 flux as being sourced by passive gas leakage from a deeply (>4 km) stored magma, whose depressurization, possibly caused by the onset of an effusive eruption on 28 Febru…

Turmoil at Turrialba Volcano (Costa Rica): Degassing and eruptive processes inferred from high-frequency gas monitoring

OVSICORI Eruptive activity at Turrialba Volcano (Costa Rica) has escalated significantly since 2014, causing airport and school closures in the capital city of San José. Whether or not new magma is involved in the current unrest seems probable but remains a matter of debate as ash deposits are dominated by hydrothermal material. Here we use high‐frequency gas monitoring to track the behavior of the volcano between 2014 and 2015 and to decipher magmatic versus hydrothermal contributions to the eruptions. Pulses of deeply derived CO2‐rich gas (CO2/Stotal > 4.5) precede explosive activity, providing a clear precursor to eruptive periods that occurs up to 2 weeks before eruptions, which are acc…

Determinazione in continuo di CO2, CH4 e H2Ov in ambiente atmosferico attraverso tecnica ad assorbimento laser (UGGA)

Molti dei composti chimici presenti nell’atmosfera terrestre prendono il nome di “gas serra”. Queste specie gassose consentono alla radiazione solare di entrare liberamente nell’atmosfera e di trattenere parte della radiazione solare riflessa dalla superficie terrestre come energia termica. Nel corso del tempo si instaura un complesso equilibrio termico tra la quantità di energia inviata dal sole e quella irradiata dalla superficie. L’alterazione di questo equilibrio, con l’aumento di uno o più gas serra in atmosfera, porta a degli squilibri termici e un conseguente innalzamento delle temperature. Questo fenomeno è definito come “effetto serra”. I principali gas serra in natura che prendono…

Emission of bromine and iodine from Mount Etna volcano

Constraining fluxes of volcanic bromine and iodine to the atmosphere is important given the significant role these species play in ozone depletion. However, very few such measurements have been made hitherto, such that global volcanic fluxes are poorly constrained. Here we extend the data set of volcanic Br and I degassing by reporting the first measurements of bromine and iodine emissions from Mount Etna. These data were obtained using filter packs and contemporaneous ultraviolet spectroscopic SO2 flux measurements, resulting in time-averaged emission rates of 0.7 kt yr-1 and 0.01 kt yr-1 for Br and I, respectively, from April to October 2004, from which we estimate global Br and I fluxes …