Search results for "Geochimica"

Gas geochemistry of shallow submarine vents in the Aegean sea (Greece)

2017

The Aegean area, which is geodynamically very active, is characterised by intense seismic activity, presence of active volcanic systems and anomalous geothermal gradients. Like other regions of intense geodynamic activity it is also characterized by extensive geogenic degassing. Gas manifestations are not only widespread on land but are also very frequent underwater. Many of these, as for example those of Milos and Santorini, are known since long time and have been previously studied although the targets were generally the hot waters or the sediments affected by the emissions (Smith and Cronan 1978, Dando et al. 1995, Price et al. 2013, Megalovassilis 2014).The present study aims at produci…

Hydrogeochemical multi-component approach to assess fluids upwelling and mixing in shallow carbonate-evaporitic aquifers (Contursi area, southern Ape…

2023

With the aim of deepening our understanding of deep-seated fluids upwelling and mixing in large regional aquifers, we performed a hydrogeochemical study of twenty-two springs in the Contursi area (upper Sele river valley, southern Apennines) by means of the measurements of chemical-physical parameters, major ions, trace elements, and stable and radioactive isotopes. Besides, we realized two updated geo-structural cross-sections in order to reconstruct the groundwater flowpath in the study area. The hydrogeochemical composition, as well as the water temperature allow to identify-three main groups of groundwater: Cold and Low salinity Groundwater (CLGW), Intermediate Salinity Groundwater (ISG…

The cycle of major and trace elements in a volcanic environment

2010

Trace elements in thermomineral waters in Greece

2020

Trace elements have a fundamental role in natural and anthropogenic systems. In waters, they present a great variability of concentrations that mostly depends on the degree of gas-water-rock interactions and geochemical conditions such as pH, temperature, redox and/or exchange reactions, etc. Even though, they are present in very low contents in host-rocks, elevated concentrations in ground or surface waters may have a hazardous impact on human health and thus, it is important to both quantify and understand their behavior in natural systems. Here we present the results of about 300 cold and thermal mineral waters collected along the entire Hellenic territory. Physicochemical parameters (te…

A literature review and new data of trace metals fluxes from worldwide active volcanoes

2012

Monitoring Volcanic Eruptions Using Trace Metals In Tree-Rings: Preliminary Results From Mt. Etna

2010

8. Active volcanoes can influence surrounding vegetation both through passive degassing during quiescent periods and through eruptive degassing, by introducing into the atmosphere several metals as gases and particles. The chemical composition of tree-rings has been generally used to investigate the effects of anthropogenic gas emissions and dendrochemical methods have successfully recorded variations in the pollution levels. The use of tree-rings analysis in active volcanic areas has shown that vascular plants could be used as archives of volcanogenic metals deposition. Tree cores of Pinus Nigra and Populus tremula were collected in sites located both on the downwind (Citelli and Mt. Fonta…

Focus on ambient levels of gas phase pollutants in the urban area of Palermo

2009

Magmatic Volatile Emissions from Ambrym and Yasur Volcanoes (Vanuatu Arc)

2008

First volatile inventory for Gorely volcano, Kamchatka

2012

We report here the very first assessment of volatile flux emissions from Gorely, an actively degassing volcano in Kamchatka. Using a variety of in situ and remote sensing techniques, we determined the bulk plume concentrations of major volatiles (H2O 93.5%, CO2, 2.6%, SO2 2.2%, HCl 1.1%, HF 0.3%, H2 0.2%) and trace-halogens (Br, I), therefore estimating a total gas release of 11,000 tons·day−1 during September 2011, at which time the target was non-eruptively degassing at 900°C. Gorely is a typical arc emitter, contributing 0.3% and 1.6% of the total global fluxes from arc volcanism for CO2 and HCl, respectively. We show that Gorely's volcanic gas (H2O/SO2 43, CO2/SO2 1.2, HCl/SO2 0.5) is a…

The recent Nyiragongo (Democratic Republic of Congo) eruption: the impact of volcanic ash fallout on drinking water and edible plants

2022

Nyiragongo is an active intraplate volcano well known for its fascinating persistent lava lake inside the crater and is recognized as one of the most dangerous volcanoes in the world as more than two million people live on its slopes, 18-25 km far from the main crater. It is located in the Virunga Volcanic Province (VVP), in the western branch of the East African Rift System (EARS), at the intersection between the Democratic Republic of Congo, Rwanda, and Uganda. Unexpectedly, on 22 May 2021, Nyiragongo produced three different lateral lava flows in the low flanks and significant amounts of volcanic gas and ash were emitted from the summit crater. For several weeks, the ash fallout strongly…