Search results for "volcan"

Major and trace element geochemistry of neutral and acidic thermal springs at El Chichón volcano, Mexico. Implications for monitoring of the volcani…

2008

Four groups of thermal springs with temperatures from 50 to 80 °C are located on the S–SW–W slopes of El Chichón volcano, a composite dome-tephra edifice, which exploded in 1982 with a 1 km wide, 160 m deep crater left. Very dynamic thermal activity inside the crater (variations in chemistry and migration of pools and fumaroles, drastic changes in the crater lake volume and chemistry) contrasts with the stable behavior of the flank hot springs during the time of observations (1974–2005). All known groups of hot springs are located on the contact of the basement and volcanic edifice, and only on the W–SW–S slopes of the volcano at almost same elevations 600–650 m asl and less than 3 km of di…

Active volcanoes as emission point sources of atmospheric mercury

2008

ercury emissions from active volcanoes are of interest for estimating the volcanogenic contribution of Hg to the atmosphere and for monitoring volcanic activity. The global Hg flux from natural sources is poorly known and considerable uncertainty still exists with respect to the complex physical and chemical reactions taking place in the atmosphere among the various Hg forms. The environmental hazard of Hg have been widely demonstrated for its high toxicity. Previous estimates from volcanic plumes are based on limited measurements and poorly determined speciation of Hg in volcanic emissions which is crucial for making reliable estimates of volcanic Hg source strengths and for predicting atm…

Mercury emissions from active volcanic areas of Italy

2005

Lidar detection of carbon dioxide in volcanic plumes

2015

Volcanic gases give information on magmatic processes. In particular, anomalous releases of carbon dioxide precede volcanic eruptions. Up to now, this gas has been measured in volcanic plumes with conventional measurements that imply the severe risks of local sampling and can last many hours. For these reasons and for the great advantages of laser sensing, the thorough development of volcanic lidar has been undertaken at the Diagnostics and Metrology Laboratory (UTAPRAD-DIM) of the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA). In fact, lidar profiling allows one to scan remotely volcanic plumes in a fast and continuous way, and with high s…

Emission of Bromine and Iodine from Mt. Etna volcano

2005

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 flu…

Volcanic Plume CO2 Flux Measurements at Mount Etna by Mobile Differential Absorption Lidar

2017

Volcanic eruptions are often preceded by precursory increases in the volcanic carbon dioxide (CO2) flux. Unfortunately, the traditional techniques used to measure volcanic CO2 require near-vent, in situ plume measurements that are potentially hazardous for operators and expose instruments to extreme conditions. To overcome these limitations, the project BRIDGE (BRIDging the gap between Gas Emissions and geophysical observations at active volcanoes) received funding from the European Research Council, with the objective to develop a new generation of volcanic gas sensing instruments, including a novel DIAL-Lidar (Differential Absorption Light Detection and Ranging) for remote (e.g., distal) …

Ultraviolet imaging of volcanic plumes: A new paradigm in volcanology

2017

Ultraviolet imaging has been applied in volcanology over the last ten years or so. This provides considerably higher temporal and spatial resolution volcanic gas emission rate data than available previously, enabling the volcanology community to investigate a range of far faster plume degassing processes than achievable hitherto. To date, this has covered rapid oscillations in passive degassing through conduits and lava lakes, as well as puffing and explosions, facilitating exciting connections to be made for the first time between previously rather separate sub-disciplines of volcanology. Firstly, there has been corroboration between geophysical and degassing datasets at ≈1 Hz, expeditin…

Advances in Bromine Speciation in Volcanic Plumes

2018

Volcanoes are a significant halogen source to the atmosphere. After water, carbon dioxide and sulfur compounds, halogens are often the most abundant gases in volcanic plumes. In the past, less attention was given to the heavy halogens bromine and iodine. However, the discovery of bromine monoxide (BrO) in volcanic plumes led to new interest especially in volcanic bromine chemistry and its impact on atmospheric processes. The BrO detection came along with advances in volcanic remote sensing techniques, in particular, robust DOAS applications and the possibility of continuous measurements by automated instruments located at safe distances from the volcano. As one of the consequences, the volc…

Noble gases in tracking volcanic processess

2007

The expressions able to evaluate the contributions of the three natural sources of helium (e.g., atmosphere,in magma, following the solubility model proposed by Nuccio and Paonita (2001). In particular, variations of He/Ne and He/CO2 ratios have been used to compute the initial and final pressure of an ascending magma (Fig. 2) (Caracausi et alii 2003b, Rizzo et alii 2006). This model was subsequently implemented with S, Cl and F (Aiuppa et alii 2004), providing an useful geochemical tool aimed at giving an early warning for forecasting volcanic eruptions. The high helium flux measured at Mefite d’Ansanto in the Irpinian Apennines, displaying a He isotope composition analogous to that of Mt.…

Le politiche di contrasto al rischio da maremoto: il caso di Stromboli

2020

This chapter, intending to be part of the reasoning on the perception of risk from extreme natural events, intends to describe the main contents of the National Emergency Plan for volcanic events of national importance on the island of Stromboli (ME) prepared in 2015 by the Department for the Civil Protection (DPC). The volcanic island of Stromboli is in fact largely exposed to the risk associated with the activities of the volcano of the same name, especially that of the tsunami. The effusive activity of the Stromboli in fact causes a marked instability of the slope known as Sciara del Fuoco which can induce, as happened at the end of 2002, a tsunami. The contribution, starting from a desc…