Reconstruction of the submerged landscape of Vatika Bay (SE Peloponnese, Greece)

Postgraduate Thesis uoadl:2780702 489 Read counter

Unit:
Κατεύθυνση Γεωλογική Ωκεανογραφία
Library of the School of Science
Deposit date:
2018-08-31
Year:
2018
Author:
Pavlidi-Palla Maria-Evangelia
Supervisors info:
Πούλος Σεραφείμ, καθηγητής, Τομέας Γεωγραφίας & Κλιματολογίας, Τμήμα Γεωλογίας και Γεωπεριβάλλοντος, ΕΚΠΑ
Σακελλαρίου Δημήτριος, Διευθυντής ερευνών, Ινστιτούτο Ωκεανογραφίας, Ελληνικό Κέντρο Θαλάσσιων Ερευνών
Ρουσάκης Γρηγόριος, Ερευνητής, Ινστιτούτο Ωκεανογραφίας, Ελληνικό Κέντρο Θαλάσσιων Ερευνών
Original Title:
Reconstruction of the submerged landscape of Vatika Bay (SE Peloponnese, Greece)
Languages:
English
Translated title:
Reconstruction of the submerged landscape of Vatika Bay (SE Peloponnese, Greece)
Summary:
Vatika Bay is located in SE Peloponnese and belongs to Laconia peninsula. The area is seismically active because it is part of the Hellenic Arc and is characterized by long term uplift, also postulated by a sequence of uplifted Late Quaternary marine terraces. This fact contrasts with the subsidence by about 3-4 m bellow the present sea level of the prehistoric city of Pavlopetri, located at Punta beach, Viglafia, in the strait of Elaphonisos. That is what is called the “Laconia Paradox”: a submerged archaeological site within a long term uplifting area. Thus, the aim of this thesis is to reconstruct the submerged prehistoric landscapes and provide understanding of the geological processes and sea-level fluctuation, which led to the present geomorphological configuration.
A marine geological survey, carried out in 2015 aboard the 14m long RV Alkyon of HCMR and positioned with GPS and differential GPS, allowed to obtain complete high resolution swath bathymetry coverage of the area. Both Multi Beam 200/400 kHz and Single Beam echosounders have been used. Bathymetric data were integrated with the acquisition of high-resolution seismic profiling data, such as Chirp, Pinger and Boomer and side scan sonar data.
The bay displays valley-like morphology. High resolution seismic profiles across the western steep slope of the Bay provide evidence that relative subsiding and uplifting areas are controlled by active faulting. The eastern slope of the Bay displays marked differences: it dips smoothly westwards, while the observed submarine terraces do not match with the ones mapped along the western slope. Holocene sediment deposition is fairly limited across the bay. A series of submerged paleo-channels occurs running off the northern shore of the Bay and buried below the recent sediments. Evidence on morphological terraces has been found at several depths ranging roughly between 40 m and 104 m bsl.
Active faulting separates the long-term uplifting parts of the surveyed area from the relative subsiding seafloor of Vatika Bay. The occurrence of three beachrock bands at different depths indicates rapid, incremental subsidence due to tectonic activity in historical times. The submerged ancient city of Pavlopetri is located on the subsiding, hanging wall of the dominant fault. Differential vertical tectonics has led to the occurrence of low sea-level terraces at different depths across the Vatika Bay.
Main subject category:
Science
Keywords:
marine geology, submerged landscape, marrine terraces, tectonic movements
Index:
Yes
Number of index pages:
2
Contains images:
Yes
Number of references:
95
Number of pages:
3
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