New insights on the relative sea level changes during the Late Holocene along the coast of Paros Island and the northern Cyclades (Greece)

Eleni Kolaiti,Nikos Mourtzas

doi:10.4401/ag-8504

Abstract

Geomorphological and archaeological indicators of former sea levels along the coast of Paros enabled us to determine and date six distinct sea level stands and the relative sea level (rsl) changes between them, as well as plot the rsl curve for the last 6,300 years. The Late Holocene history of the rsl change in Paros began with the sea level at 4.90 ± 0.10 m below mean sea level (bmsl) dated to the Late Neolithic period (4300 BC-3700 BC). The next sea level at 3.50 ± 0.20 m bmsl is dated to the Geometric and Archaic period of the Cyclades (1050 BC-490 BC) and most probably lasted during the Hellenistic period (323-146 BC). The sea level at 2.40 ± 0.25 m bmsl is dated to the Roman period (146-400 AD) and the next sea level at 1.35 ± 0.20 m bmsl to the Venetian period of the Cyclades (1207-1537). The sea level at 0.80 ± 0.10 m bmsl is dated to after the Venetian period, during the Ottoman rule of the island (1537-1821). The youngest sea level stand at 0.45 ± 0.10 m is attributed to the recent change in the sea level after the late 19th c. onward. The separation between glacio-hydro-isostatic signals and the observed rsl change on Paros Island, in an area of seismic quiescence, demonstrates a significant tectonic component in the rsl changes. Moreover, the sea level stands deduced from Paros in comparison with those from the northern Cyclades indicate a uniform tectonic behaviour of the entire northern and central section of the Cyclades plateau.

Highlights

Relative sea level changes in the Mediterranean Sea are complex and variable, due to crustal dynamics, volcanism and glacio-isostatic adjustment [e.g. Benjamin et al, 2017]
The Late Holocene history of the rsl change in Paros began with the sea level at 4.90 ± 0.10 m below mean sea level dated to the Late Neolithic period (4300 BC-3700 BC)
The sea level stands deduced from Paros in comparison with those from the northern Cyclades indicate a uniform tectonic behaviour of the entire northern and central section of the Cyclades plateau

Summary

Introduction

Relative sea level (rsl) changes in the Mediterranean Sea are complex and variable, due to crustal dynamics, volcanism and glacio-isostatic adjustment [e.g. Benjamin et al, 2017]. Eleni Kolaiti and Nikos Mourtzas the Last Glacial Maximum (LGM) sea levels (~20,000 years ago) from 100 m to 135 m below present, with associated strong gradients in the load stresses in the lithosphere and crust across the continental margins [Lambeck, 2014]. This glacio-hydro-isostatic adjustment model is combined with the active tectonics of the Mediterranean region driven by the long-lasting convergence of the African and Eurasian tectonic plates running along an east–west boundary [Anzidei et al, 2014]. The Industrial Revolution and the accelerated climate change from the eighteenth century onward have brought about a global rise in sea level of 0.25 ± 0.05 m [Church et al, 2011; Cazenave et al, 2014; Jevrejeva et al, 2014]

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Discussion

Conclusion