0000000000301813
AUTHOR
D'alessandro Walter
Preliminary study on geogenic degassing through the big karstic aquifers of Greece
Non-volcanic degassing contributes to the C-cycle by providing on a global scale a significant amount of CO2 emitted through diffuse earth degassing processes (Kerrick et al 1995). Due to the elevated solubility of the CO2 in water, in the areas where high CO2 fluxes directly affect regional aquifers, most of it can be dissolved, transported and released by groundwaters. Therefore, quantification of this contribution to the atmosphere has a substantial implication for modeling the global carbon cycle. According to Chiodini et al. (2000), total dissolved inorganic carbon (TDIC) concentrations and δ13CTDIC values of groundwaters are useful tools to both quantify the geogenic degassing and dis…
The history of Ludovico Sicardi and the birth of geochemical
Ludovico Sicardi was a chemist and a pharmacist, and a passionate researcher, enthusiastic about phenomena related to volcanic activity. Due to a field survey within a project of mining research committed by a private company, he has the opportunity to visit the island of Vulcano (Eolie - Sicily), from December 1921 to June 1922. He was completely fascinated by the wild island of Vulcano and its gas manifestations. During several successive field trips in Vulcano, he observed and described the fumarolic field on a systematic basis, measuring the temperatures and recording their variations over time. He was one of the first to perform chemical analysis of fluids emitted by fumaroles in Vulca…
Geochemical investigation of trace metal pollutants in the Oreto river, Palermo (Italy)
In the past, three main rivers, named Kemonia, Papireto and Oreto, were present in the plain of Palermo, in northwestern Sicily. Today, only the latter one has been preserved from the unregulated urban expansion. Fortunately, over the last ten years, attention and consciousness towardsthe Oreto river and its delicate ecosystem has grown considerably, also thanks to many associations and citizens’ committees involved in protecting, preserving and valorising the precious area. In this context, our study is focused on a hydrogeochemical investigation of its surface water quality. The Oreto river flows for about 20 km within a catchment area of about 130 km2. Over the past three years, numerous…
Estimation of CO2 release from thermal springs to the atmosphere
Introduction Geodynamically active regions have long been recognized as areas of anomalous Earth degassing [Irwin and Barnes, 1980]. Areas found at plate boundaries are characterized by seismic, volcanic and geothermal activity as well as ore deposition. These processes are enhanced by the circulation of hydrothermal fluids in the crust, which transport volatiles from the deep crust or mantle to the surface [King, 1986]. Kerrick and Caldera, [1998], were the first to indicate the significant contribution of the CO2 degassing by extensional tectonic and hydrothermal activity in metamorphic belts during the Phanerozoic. Moreover, further studies concerning gas emissions from diffuse degassing…
The impact of Mt. Etna's ash plume on the chemical composition of meteoric deposition
Mt. Etna, in eastern coast of Sicily (Italy), is one of the most active and most intensely monitored volcanoes of the planet. It is the biggest volcanic point source of volcanic gases and particles to the troposphere in the Mediterranean basin. On the morning of December 24th 2018, a new lateral eruption of the Mount Etna started. This eruption was related to an intrusion of a magmatic dike on the high eastern flank of the volcano, which a two kilometers long fracture in the NNW - SSE direction. At the same time, the summit craters also produced a continuous strombolian activity generating a very dense dark ash plume, dispersed by the wind into the southeastern direction. This volcanic even…
CO2 release to the atmosphere from thermal springs of Sperchios Basin and northern Euboea (Greece): The contribution of “hidden” degassing
Abstract Greece is a region characterised by intense geodynamic activity that favours the circulation of hydrothermal fluids in the crust transporting volatiles from either the deep crust or the mantle to the surface. Elevated heat flow values are detectable at Sperchios Basin and North Euboea (central Greece), two areas defined by a system of deeply rooted extensional faults and Quaternary volcanic activity. This setting contributed to the formation of numerous hydrothermal systems, which are mostly expressed as CO2-rich thermal springs with intense bubbling. The CO2 output from six bubbling pools has been determined by flux measurements with the use of the floating chamber method. The hig…
Microbial impact on the isotope composition of methane in both thermal and hyperalkaline waters of central Greece
Introduction The different origins of methane can be subdivided in biogenic (either directly produced by microbial activity or deriving by decay of organic matter at T > 150°C) and abiogenic (from pure inorganic reactions). Among the latter, one of the most debated origins comes from serpentinization processes of ultramafic rocks in ophiolitic sequences at low temperatures (T < 80 °C). Moreover, further secondary processes (diffusion, inorganic or microbial oxidation, etc.) may also contribute and thus mask the original chemical and/or isotope composition. Primary and secondary processes acting on CH4 can be recognised mainly through its isotope (d13C and d2H) composition and the rati…
Major ions and trace elements composition of rainwater around the two industrial areas of Milazzo and Priolo Gargallo (Sicily - Italy)
This database shows the concentration of major ions and trace elements in rainwater from two polluted industrial areas of Sicily, Milazzo and Priolo Gargallo, collected from June 2018 to July 2019, through a network of 11 bulk collectors to sample bulk atmospheric deposition, for a total of 131 samples collected. Different sources, both natural and anthropogenic, for both major ions and trace elements have been recognised. This study also highlighted some critical issues with common methods of sampling and analysing atmospheric deposition. The analysis and comparison of two different aliquots, filtered and unfiltered rainwater, has shown that the filtration method removes from the sample a …