Spatial distribution of sea-level markers on Lesvos Island (NE Aegean Sea): Evidence of differential relative sea-level changes and the neotectonic implications

Abstract

The aim of this study is to provide new data on relative sea-level changes and neotectonics of the northeastern Aegean Sea region (Eastern Mediterranean) through the analysis of the coastal geomorphology of Lesvos, the third largest Greek island. There is a paucity of presently available data in this sector of the Aegean Sea, which is a tectonically active area strongly controlled by the North Anatolian Fault. In this paper, morphological, biological and sedimentary records of paleo-sea levels have been used to reconstruct relative sea-level changes, to identify variations in the tectonic regimes as well as to assess the paleoseismicity in the studied areas. According to the results, late Quaternary relative sea-level changes at Lesvos were not homogenous and variations in the tectonic setting played a crucial role in the coastal evolution. The NW-SE trending faults on the southern shore of the island control a significant uplift affecting about 30 km of coastline. This uplift trend is controlled by the footwall of the Lesvos Fault, a major offshore normal fault that has been subject to relatively little quantitative investigation. Radiocarbon dating indicated that the last co-seismic uplift took place at 3365-3963 cal yr BP and resulted in about 0.75 m of vertical displacement. In contrast, all the paleo-sea-level markers mapped in the northeastern sector were presently underwater and, despite the high seismicity of the area, no evidence of coastal uplift was observed in this part of the island. Thus, the paper provides the first field evidence of a differential late Quaternary evolution of Lesvos Island. In addition, results represent the first quantitative information on the activity of the Lesvos Fault, suggesting a reconsideration of its importance in the neotectonics of the area.

An updated database of Holocene relative sea level changes in NE Aegean Sea

“…2c) is strongly influenced by the local fault activity affecting the area (Stiros et al, 2000;Pavlides et al, 2009;Vacchi et al, 2012a). In Ephesus and SW Samos, current elevation of the RSL indicators is reported as controlled by the active tectonic subsidence (Mourtzas and Marinos, 1994;Stiros et al, 2000;Pavlopoulos et al, 2012a).…”

“…4). Here, the current elevation of the RSL indicators is the result of repeated major co-seismic uplifts controlled by the footwall of local normal faults (Stiros et al, 2000;Vacchi et al, 2012a). The active tectonics of this area fragments western Minor Asia in roughly a WeE direction, perpendicular to the coastline, creating numerous small blocks with differential (vertical and horizontal) motion (Pavlopoulos et al, 2012a).…”

Coastal notches: Their morphology, formation, and function

“…Limestone notches, which are generally assumed to have been cut by bioerosion or chemical dissolution, have been particularly important in determining the effect of late Holocene tectonic events around the microtidal coasts of Italy, Greece, Turkey, and elsewhere in the Mediterranean (Pirazzoli et al, 1982(Pirazzoli et al, , 1989(Pirazzoli et al, , 1994aStewart and VitaFinzi, 1996;Rust and Kershaw, 2000;Stiros et al, 2000;Kershaw and Guo, 2001;Benac et al, 2004;Ramırez-Herrera et al, 2004;Antonioli et al, 2006;Morhange et al, 2006;Vacchi et al, 2012;Evelpidou et al, 2012bEvelpidou et al, ,c, 2014Abad, 2013). Rapid seismic activity in the Mediterranean has been punctuated by intervening periods characterized by slow crustal deformation.…”

Assessing enigmatic boulder deposits in NE Aegean Sea: importance of historical sources as tool to support hydrodynamic equations

“…Those located at the southern coast of the island are among the most significant ones: according to their length, their seismic sources and their geometry, a maximum earthquake potential of about 6.6-6.8 M s was calculated for these faults (Pavlides et al, 2009;Vacchi et al, 2012).…”