Publication Date:
2022-06-07
Description:
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 12 L s 1, which are comparable with
the total SGD flux in the basin of 17 L s 1 obtained from radon measurements. The integrated SGD
flux over the Donnalucata coast estimated on the basis of Ra isotopes was around 60 m3 s 1 per km of
the coast. Spatial variations of SGD were observed in the Donnalucata boat basin, the average 222Rn activity concentration in seawater varied fromw0.1 kBq m 3 to 3.7 kBq m 3 showing an inverse relationship
with salinity. The continuous monitoring carried out at the site closest to the coast has revealed an
inverse relationship of 222Rn activity concentration on the tide. The 222Rn concentrations in seawater varied
from 2.3 kBq m 3 during high tides to 4.8 kBq m 3 during low tides, thus confirming an influence of
the tide on submarine groundwater discharge. Stable isotopes (d2H and d18O) showed that SGD samples
consist up to 50% of groundwater. Geo-electrical measurements showed a spatial variability of the salt/
fresh water interface and its complex transformation in the coastal zone. The presented results imply
that in the studied Donnalucata site there are at least two different sources of SGD, one superficial, represented
by mixed fresh water and seawater, and the second one which originates in a deeper limestone
aquifer.
Description:
Published
Description:
81-101
Description:
JCR Journal
Description:
reserved
Keywords:
Submarine groundwater discharge
;
Groundwater
;
Seawater
;
Radioactive and stable isotopes;
;
Seepage measurement
;
Geophysical survey
;
Numerical modelling
;
Mediterranean Sea
;
03. Hydrosphere::03.02. Hydrology::03.02.03. Groundwater processes
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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