Relative sea level change and climate change along the eastern Adriatic coast (SEALeveL)

Fund sources: Croatian Science Foundation

Duration: 31.01.2020 - 30.01.2024
Project leader: prof. Sanja Faivre, PhD
Funds:  997.760,00 HRK
Project number: HRZZ-IP-2019--04-9445



The aim of the proposed project was to study the relative sea level change and climate changes along the eastern Adriatic coast using two main markers of algal rims and dripstones with phreatic growth. The algal rims created by the alga Lithophyllus byssoides have proven to be good indicators of previous sea levels at microtidal shores, as algae can live only in the tidal zone and therefore represent the highest biogenic build-up in the Mediterranean. Dripstones with phreatic growth are a very rare appearance in caves of the littoral area where the ground water level is dictated by sea level. The formation of phreatic growth in the narrow zone of the ground water fluctuation caused by the tides, and the ability to precisely determine their age, makes it an excellent indicator of sea level. The cave environment where it is formed also protects it from erosion, thus ensuring its long-term preservation. Both of these markers, algal rims and dripstones with phreatic growth, allow us to determine the index points of change that are used in building the relative sea level curve. These index points are then associated with phases of rapid climate change, based on analyses of stable isotopes obtained from the algal rims. The relative sea level change curves will be quantified using the integrated Gauss process model with the known error in-variables integrated Gaussian process (EIV-IGP). The relative sea level curves from various parts of the Adriatic, together with the stable isotope data from the algae, represent the basis for understanding the cause of changes: climate change, isostatic shifts and tectonics. Research and understanding of why and how sea level has changed in the past will enable better forecasts of future change and evaluations of vulnerability of littoral areas, which may contribute to better organisation and preparation of local communities.