Search results for "volcan"

Halogens and trace metal emissions from the ongoing 2008 summit eruption of Kīlauea volcano, Hawai`i

2012

Volcanic plume samples taken in 2008 and 2009 from the Halemàumàu eruption at Kīlauea provide new insights into Kīlauea's degassing behaviour. The Cl, F and S gas systematics are consistent with syn-eruptive East Rift Zone measurements suggesting that the new Halemàumàu activity is fed by a convecting magma reservoir shallower than the main summit storage area. Comparison with degassing models suggests that plume halogen and S composition is controlled by very shallow (<3m depth) decompression degassing and progressive loss of volatiles at the surface. Compared to most other global volcanoes, Kīlauea's gases are depleted in Cl with respect to S. Similarly, our Br/S and I/S ratio measurem…

Elemental and isotope covariation of noble gases in mineral phases from Etnean volcanics erupted during 2001–2005, and genetic relation with peripher…

2008

Abstract During 2001–2005, Mount Etna was characterized by intense eruptive activity involving the emission of petrologically different products from several vents, which involved at least two types of magma with different degrees of evolution. We investigated the ratios and abundances for noble-gas isotopes in fluid inclusions trapped in olivines and pyroxenes in the erupted products. We confirm that olivine has the most efficient crystalline structure for preserving the pristine composition of entrapped gases, while pyroxene can suffer diffusive He loss. Both the minerals also experience noble gas air contamination after eruption. Helium isotopes of the products genetically linked to the …

Micro-thermometry and minerochemical composition of ultramafic xenoliths and minerals from Mt. Vulture volcano (southern Italy)

2022

Here minerochemical composition and micro-thermometric data of ultramafic xenoliths (wehrlite) and loose xenocrysts (olivine and Cr-diopside) from the last melilitite-carbonatite explosive volcanic activity of Mt. Vulture volcano. In addition, some geometrical parameters of pelletal lapilli are reported.

Descriptive Epidemiology of Human Thyroid Cancer: Experience From a Regional Registry and The “Volcanic Factor”

2013

Thyroid cancer (TC), the most common endocrine tumor, has steadily increased worldwide due to the increase of the papillary histotype. The reasons for this spread have not been established. In addition to more sensitive thyroid nodule screening, the effect of environmental factors cannot be excluded. Because high incidences of TC were found in volcanic areas (Hawaii and Iceland), a volcanic environment may play a role in the pathogenesis of TC.In January 2002, the Regional Register for Thyroid Cancer was instituted in Sicily. With a population of approximately 5 million inhabitants with similar genetic and lifestyle features, the coexistence in Sicily of rural, urban, industrial, moderate-t…

First combined flux chamber survey of mercury and CO2 emissions from soil diffuse degassing at Solfatara of Pozzuoli crater, Campi Flegrei (Italy): M…

2014

Abstract There have been limited studies to date targeting gaseous elemental mercury (GEM) flux from soil emission in enriched volcanic substrates and its relation with CO 2 release and tectonic structures. In order to evaluate and understand the processes of soil–air exchanges involved at Solfatara of Pozzuoli volcano, the most active zone of Campi Flegrei caldera (Italy), an intensive field measurement survey has been achieved in September 2013 by using high-time resolution techniques. Soil–air exchange fluxes of GEM and CO 2 have been measured simultaneously at 116 points, widely distributed within the crater. Quantification of gas flux has been assessed by using field accumulation chamb…

New evidences on mercury emissions from Earth volcanism

2010

Mercury from volcanoes: fluxes and speciation

2008

Mercury is a toxic bio-accumulating metal that, due to its volatility has an extended atmospheric lifetime. Understanding Hg sources and sinks is therefore has importance on the global scale. We present new measurements of volcanic Hg from Mount Etna and Vulcano in Italy and Masaya volcano in Nicaragua to improve our estimates of the volcanic Hg flux. In contrast to other metals emitted from volcanoes, volcanic Hg can exist in 3 forms, namely gaseous elemental mercury (GEM), reactive gaseous mercury (RGM) and in the particle phase. These measurements also represent the first fully speciated measurements of volcanic Hg, as well as the first high time resolution measurements of gaseous Hg. Vo…

New Inferences on Magma Dynamics in Melilitite-Carbonatite Volcanoes: The Case Study of Mt. Vulture (Southern Italy)

2022

This study provides the first micro-thermometric data of fluid inclusions (FIs) in mafic loose (disaggregated) xenocrysts and ultramafic xenoliths in explosive products of the melilitite-carbonatite Mt. Vulture volcano (southern Italy). Pure CO2 late stage FIs hosted in rock-forming minerals of wehrlite xenoliths and clinopyroxene xenocrysts were trapped at the local crust-mantle boundary (32 km). In contrast, trapping pressures within the loose olivine xenocrysts are from 3.2 to 4.5 kbar (8–13 km). Considering the ongoing degassing of mantle-derived CO2 rich gases, together with seismic evidences of the presence of low amount of melts at depth, and the tectonic control of the past volcanic…

Volcanic risk and the role of the media. A case study in the Etna area

2019

On December 24, 2018, the Etna volcano has recorded a significant eruption. Linked to this phenomenon, after a seismic swarm of 72 shocks, a 4.8-magnitude earthquake struck a large area North of Catania city, on the Eastern coast of Sicily. Six villages reported 28 injured people and damages to the building. According to seismologists the earthquake had an unusual level of magnitude. Yet, despite the real danger of this event, many people who live around the volcano, in one of the most densely populated areas of Sicily, perceived these facts in an ambivalent way. Indeed, their lives continued as before even in awareness of the natural hazard, while several media presented the situation as r…

Mitigating the highest volcanic risk in the World: a multidisciplinary strategy for the Neapolitan area

2020

Neapolitan volcanic area is by far the highest volcanic risk one in the World, due to the presence of three active volcanic areas (Vesuvius, Campi Flegrei, Ischia) with an extreme population density: three million people live within 20 km from a possible volcanic vent. Volcanic risk in these areas is strictly associated to seismic risk, and to other secondary risks as landslides and flooding (De Natale et al., 2019; 2020). The mitigation of such an extreme risk can only be afforded by considering volcanological, as well as economical, urban and social issues. All these highly multidisciplinary aspects must be jointly recognized and shared by both volcanologists and decision makers, in a glo…