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A marine sediment core from the western Mediterranean provides a new high-resolution 4500 year record of palaeomagnetic secular variation and relative palaeointensity. In 2013, the 7.1 m C5 core was recovered from the Tyrrhenian Sea as part of the NextData climate data project. The coring site, 15 km offshore from the Volturno river mouth, is well located to record combined marine and terrestrial palaeoclimatic influences, and the fine-grained, rapidly deposited sediments are effective palaeomagnetic recorders. We investigate the palaeomagnetic field direction and strength recorded in the core, which provide a valuable high-resolution record of Holocene geomagnetic variation in the area. Using rock magnetic techniques, we constrain the magnetic mineralogy of the studied sediments and confirm their suitability for palaeomagnetic analysis. Palaeomagnetic declination and inclination records were determined by stepwise alternating-field demagnetization, and relative palaeointensity estimates were obtained based on normalization to anhysterestic and isothermal remanent magnetization and to magnetic susceptibility. The age of the core is well constrained with a tephra and biostratigraphic age model, and its magnetic records are compared with relevant core and model data for the region, demonstrating that our record is compatible with previous results from the area. An automated curve matching approach is applied to assess the compatibility of our data with the existing secular variation path for the Mediterranean area.

Abstract: The high-resolution study of sediment core C90-1 m collected at the continental shelf of the Gulf of Salerno (southern Tyrrhenian Sea) provides an excellent opportunity to show paleoenvironmental changes during the last 500 years induced by natural variability and human impact. Based on 210Pb and 137Cs measurements, the sedimentation rate results 0.20 cm/year for the last 100 years. The high sampling resolution (1 cm sample spacing) of core C90-1 m, 105 cm long, provides a time resolution of approximately 5 years/cm. Quantitative changes in the planktonic and benthonic foraminiferal assemblages combined with δ18O G.ruber variations allow to identify regional climatic and oceanographic signals. A significant turnover between herbivorous and opportunistic species and carnivorous planktonic foraminifera after the Maunder event suggests changes in river runoff and/or an increase in coastal flooding events in the studied area. Variations in the microfauna since 1940 yAD document environmental changes induced by the construction of a dam in the Sele River.

Abstract: In order to assess the effects of possible future sea-level rise in the Sele plain, the lowlands prone to inundation and the rate of coastal erosion in the years 2050 and 2100 have been discussed and some conclusions are here proposed. The sea level at these two dates was calculated as the combination of three components: response of Italian coastal zones to the past deglaciation, variations in ocean volume due to the global warming and vertical land movements. The morpho-stratigraphical data, chronologically supported by 14C and by archeo-tephro-stratigraphical dating, have allowed the identification of paleo-sea levels of the upper Pleistocene and Holocene (Amato et al. 2011). Such paleo-sea levels compared with those of the tectonically stable areas (Lambeck et al. 2011), permitted the detection of the different vertical land movements in the study area. In particular, in the SE sector of the coastal plain, the Holocene paleo-sea levels are slightly higher (ca. 1–2 m). These values could be considered due to a gentle uplift of the area during Holocene times (0.22 mm/year). In the central sector of the plain, near the Sele river mouth and in the NW sector, between the Sele and Tusciano river mouths, the altitude of the Late Quaternary coastal and lagoonal deposits are slightly lower (ca. 2–3 m). These values could be related to a gentle subsidence of the area during the Holocene (0.4 mm/year). The sea level rise of 5.9 mm/year (IPCC 2007) and 14 mm/year (Rahmstorf 2007) was considered to represent the maximum trends in the ocean volume variation at global scale. The third component, the glacio-hydro-isostasy, was represented by the value of 0.44 mm/year identified by Lambeck et al. (2011) at the Sele plain. The sum of these three components allowed to identify three sea-level scenarios slightly different for the northern and the southern sector of Sele plain, with values ranging from 357 to 1,526 mm and from 307 to 1,424 mm, respectively. For each scenario a simple approach was used, mainly based on the topographic elevation analysis of study area, applied to identify the extension of possible areas of inundation. It corresponds to a minimum value of about 0.42 km2 for the 2050 AD and a maximum value of 7.6 km2 for the 2100. Furthermore, according to the methodology proposed by Davidson-Arnott (2005), also the beach erosion was evaluated. The computations showed a potential mean landward retreat of the shoreline ranging from 19 to 93 m.