Search results for "submarine groundwater discharge"
showing 7 items of 7 documents
Geochemical characterization of groundwater and submarine discharge in the south-eastern Sicily
2006
Abstract The main results of a hydrogeochemical survey carried out during 2002–2003 along the coast of the south-eastern Sicily, which aimed at geochemical characterization of both groundwater chemistry and submarine groundwater discharge (SGD) in the area are presented. A general frame of chemical processes affecting the studied groundwater and SGD point out that most samples fall within the calcite-anhydrite-dolomite field (CAD). The chemical composition of the samples within the CAD triangle is essentially controlled by calcite, dolomite and gypsum dissolution, which are the main minerals of the carbonate rocks hosting the aquifers. An additional process evidenced in this study is a mixi…
Quantifying submarine groundwater discharge in the coastal zone via multiple methods
2006
Submarine groundwater discharge (SGD) is now recognized as an important pathway between land and sea. As such, this flow may contribute to the biogeochemical and other marine budgets of near-shore waters. These discharges typically display significant spatial and temporal variability making assessments difficult. Groundwater seepage is patchy, diffuse, temporally variable, and may involve multiple aquifers. Thus, the measurement of its magnitude and associated chemical fluxes is a challenging enterprise. A joint project of UNESCO and the International Atomic Energy Agency (IAEA) has examined several methods of SGD assessment and carried out a series of five intercomparison experiments in di…
Global Coastal Permeability database (GCPdb)
2023
The Global Coastal Permeability Database contains both the input and output data of the Global Coastal Permeability Model developed by Tschaikowski et al. (2023) and available at DOI: 10.5281/zenodo.7845568. The model is implemented in R and calculates the coastal permeability for each shoreline segment of the global shoreline vector created by Sayre et al. (2019) with a 30-meter resolution and covering a spatial extent of 180.0°W to 180.0°E longitude and 60.8°S to 83.7°N latitude. The coastline is separated into three sections (A: coastal aquifer section, B: shoreline section, C: shallow section), and permeability values and ranges are provided for each section. Permeability values were de…
Stable isotopes of water as a tool to study groundwater–seawater interactions in coastal south-eastern Sicily
2009
Summary Stable isotopes of hydrogen (δD) and oxygen (δ 18 O) in groundwater, submarine springs and seawater collected in coastal south-eastern Sicily were investigated. While the spatial distribution of δ 18 O in groundwater showed that most of the heavy-isotope-depleted samples (from −5.7‰ to −6.9‰) were located in the higher portion of the Hyblean Mountains, more positive values (from −3.4‰ to −5.6‰) were found in the marginal areas. The isotope composition of submarine springs was characterized by significant variability (δ 18 O between −5.6‰ and +1.0‰ and δD between −30‰ and +5.0‰) reflecting seasonal variations and different seawater contributions. The isotopic and chemical composition…
Characterisation of submarine groundwater discharge offshore south-eastern Sicily
2005
A complex approach in characterisation of submarine groundwater discharge (SGD) off south-eastern Sicily comprising applications of radioactive and non-radioactive tracers, direct seepage measurements, geophysical surveys and a numerical modelling is presented. SGD fluxes in the Donnalucata boat basin were estimated by direct seepage measurements to be from 4 to 12Ls(-1), which are comparable with the total SGD flux in the basin of 17Ls(-1) obtained from radon measurements. The integrated SGD flux over the Donnalucata coast estimated on the basis of Ra isotopes was around 60m(3)s(-1) per km of the coast. Spatial variations of SGD were observed in the Donnalucata boat basin, the average (222…
Submarine groundwater discharge investigations in Sicilian and Brazilian coastal waters using an underwater gamma-ray spectrometer
2006
Abstract Submarine groundwater discharge (SGD) in coastal zones was monitored using in situ underwater gamma-ray spectrometry of radon decay products ( 214 Bi). Several sites were visited during the IAEA'2002 expedition to south-eastern Sicily, where SGD variations were observed in the Donnalucata boat basin. The continuous monitoring carried out for 3 days at the site closest to the coast revealed an anticorrelation dependence of 222 Rn concentration with tide and salinity. The 222 Rn activity concentrations in seawater varied from 2.3 kBq m −3 (during high tides) to 4.8 kBq m −3 (during low tides). In situ gamma-ray spectrometric measurements were also carried out during the IAEA–UNESCO'2…
Isotope distribution of dissolved carbonate species in southeastern coastal aquifers of Sicily (Italy)
2007
Concentrations of major ions and the δ13C composition of dissolved inorganic carbon in groundwater and submarine groundwater discharges in the area between Siracusa and Ragusa provinces, southeastern Sicily, representing coastal carbonate aquifers, are presented and discussed. Most of groundwater analysed belongs to calcium bicarbonate type, in agreement with the geological nature of carbonate host rocks. Carbonate groundwater acquires, besides the dissolution of carbonate minerals, dissolved carbon (and the relative isotopic composition) from the atmosphere and from soil biological activity. In fact, δ13C values and total dissolved inorganic carbon contents show that both these sources con…