The Mediterranean Sea has been sampled irregularly by research vessels in the past, mostly by national expeditions in regional waters. To monitor the hydrographic, biogeochemical and circulation changes in the Mediterranean Sea, a systematic repeat oceanographic survey programme called Med-SHIP was recommended by the Mediterranean Science Commission (CIESM) in 2011, as part of the Global Ocean Ship-based Hydrographic Investigations Program (GO-SHIP). Med-SHIP consists of zonal and meridional surveys with different frequencies, where comprehensive physical and biogeochemical properties are measured with the highest international standards.
View Article and Find Full Text PDFSci Total Environ
December 2023
In the period 1987-2017, a series of physical and chemical measurements related to oxygen variability at a trough area with a maximum depth of ~420 m in the West Saronikos Gulf, reveal the following: In the early 90s, deep winter mixing occurred resulting in an oxygenation down to ~420 m followed by an oxygen decline. This decline reached near-bottom hypoxic conditions (O < ~62 μM (μmol/L)) after 1998, while a denitrification phase occurred after 2000 and a complete bottom anoxia in 2005. In June 2012, an oxygenation down to ~350 m was detected that most likely occurred in winter 2012.
View Article and Find Full Text PDFIn-situ underwater gamma-ray spectrometer KATERINA was used for continuous measurements of radon progenies ((214)Pb, (214)Bi), thoron progeny ((208)Tl) and (40)K in submarine groundwater discharge (SGD) sites at Kalogria Bay, SW Peloponnesus (Greece). The spectrometer was deployed attached on measuring platform along with two conductivity - temperature data loggers while underwater battery packs supplied the system for acquisition periods up to 25 days. The radionuclide time series together with salinity data were obtained for spring (wet) and summer (dry) seasons.
View Article and Find Full Text PDF