الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 241 |  |  |
| | | from | 241 | | |
Abstract
Marine geophysical techniques are quite efficient in remote seabed classifications and geoarchaeological investigations due to their capability of excavating large seabed areas with high details in a short time.
The present study aimed to highlight the impact of sea level changes on the coastal geomorphology of Alexandria city during the last two millennia. Geomorphologic and seismic surveys were implemented in the study area by using side scan sonar, sub-bottom profiler and echo-sounder, then the acoustic results were calibrated with dated core samples and ROV camera images. Results of the sonar imaging and bathymetric mapping outlined submerged margins of archaeological remains related to the ancient Ptolemaic Royal ports across the Eastern Harbor of Alexandria, and buried Greek cities across the seafloor of Abu-Qir Bay. The noticed irregular surfaces and non-uniform structural form of the submerged archaeological remains emphasized the effect of past sea level rises and natural hazards on the ancient sites. from seismic interpretations, the coastal geomorphology reveals significant changes since the Mid-Holocene time. Geodynamic processes interacted with natural hazards, global scale climatic changes and human activities are the driving factors for these geomorphological changes. The evaluation of the port site evolution looks crucial in determining the degree of contribution of each factor in the subsidence of the underwater ancient site.
The evolution of the port site from the Late Ptolemaic period to the period after 365 AD where massive burial for the port structure was existed, indicates the occurrence of sudden natural hazards originated from seismic waves; therefore, a destructive tidal (tsunami) wave accompanied by sediment slumping (coastal land-sliding) seems to be the dominant factors for this burial during this period. Since this time till the Late Roman period, the eustatic sea level rise had caused the inundation of the coastal area, also the inadequate construction piling and excessive sediments load derived from the Heptastadium tombolo had increased the burial and submergence of the port site.