1,2,1,2- 1Istanbul Technical University, Faculty of Mines, Geological Engineering, Istanbul, Türkiye (onay20@itu.edu.tr)
- 2MATAM (ITU Türkiye İş Bankası Marmara Active Fault Hazard and Risk Application and Research Center), Istanbul Technical University, Istanbul, Türkiye
The İzmir–Dikili coast (NE Aegean Sea, Türkiye) is a key area for studying coastal evolution due to its complex geological, tectonic, and climatic setting.
Beachrocks are widely used as reliable proxies for reconstructing paleo-sea levels and constraining regional relative sea-level (RSL) changes. This study investigates submerged beachrocks and associated archaeological structures, documented for the first time along this coast, to reconstruct Holocene RSL evolution of the region.
We employed an integrated methodology including underwater observations, aerial photogrammetry, coring, petrographic analyses, and radiocarbon dating within a GIS framework. High-resolution bathymetry data revealed continuous submerged beachrock outcrops with a total length of approximately 3.5 km, situated at depths between 0.38 and 1.50 m below the present mean sea level. Petrographic analyses characterized these deposits as carbonate-cemented sandstones and conglomerates. Geomorphologically, the beachrocks exhibit both tabular and deformed block structures. Archaeological remains, such is reported to be a submerged pier, were also documented at compatible depths.
The distribution and depth of these indicators, combined with the regional geology demonstrate a Holocene RSL rise for the Dikili coast. We interpret this trend as being primarily controlled by long-term subsidence of the Dikili Graben. Preliminary calculations suggest a rate of approximately 0.4 mm/yr, pending validation by ongoing radiocarbon dating.
This study establishes a robust framework for integrating geological, geomorphological, and archaeological indicators to investigate Holocene sea-level changes in tectonically active coastal settings. Our findings contribute new and critical data to the regional sea-level database of the Northern Aegean.
This study was supported by TUBITAK 1919B012462336 grant and Istanbul Technical University Research Fund, FLO-2025-47205.
How to cite: Onay, T., Burasoglu, S. F., Tulumen, E. B., Kahvecioglu, A. A., and Tari, U.: Holocene Relative Sea-Level Changes and Coastal Evolution Along the Izmir–Dikili Coast (NE Aegean Sea) Insights from Submerged Beachrocks and Archaeological Evidence, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-9584, https://doi.org/10.5194/egusphere-egu26-9584, 2026.
