The GE.N.ESIS project: Activities / Δραστηριότητες

Scroll down for the most recent activities !

PRELIMINARY RECONNAISSANCE

Preliminary reconnaissance took place in Methoni during late April 2012. Coastlining and underwater reconnaissance were some of the activities undertaken among others. Finalising logistic arrangements was also a major task for the GE.N.ESIS Project team.

Wildlife...

Coastlining is not always easy, especially at the land's end...

View of the (enclosed nowadays) ancient harbour
of Methoni and the harbour's submerged breakwater

Trying to find a passage through the submerged breakwater, for the
survey boat to enter into the enclosed nowadays ancient harbour...
The definition of minimum depth inside the ancient harbour was
a critical task for the future safety of survey team and equipment.

SEA TRIALS

The aim of the sea trials was the simulation of the actual survey tasks that will be overtaken overseas for the GE.N.ESIS project, so that problems and issues related to the actual survey and its specificities can be identified early.

The objectives of the Sea Trials were to interface and set up survey instruments for sea, to test ultra-shallow water configurations / deployment methods of Sidescan Sonar and Magnetometer as well as to acquire data samples from Sidescan Sonar and Magnetometer at sea (under various ultra-shallow water towing configurations) and assess its quality, hence assess the optimum towing method.

Equipment tests ashore just before mobilisation

Preparing a custom-built catamaran for towing the Sidescan sonar

Magnetometer setup afloat, during the sea trials

Sidescan Sonar deployment trials for ultra-shallow water survey,
under different towing configurations. The assessment of acquired
data samples (data quality) may define the optimum towing configuration.

MOBILISATION

Mobilisation can be hard and enjoying at the same time... Especially when you cross the whole of Europe to reach your destination by car.

Departure from Plymouth (UK)

Doukato cape in Zante

SIDESCAN SONAR SURVEY

The fieldwork started with an ultra shallow water sidescan sonar survey of the submerged prehistoric settlement and the submerged ancient harbour and breakwater at the Methoni bay.

The Geoacoustics sidescan sonar and towfish, Coda DA1000 acquisition system, C-Nav 2050G DGNSS, and Site Searcher Navigation system were used for the task onboard a 5.4m RHIB.

Various survey techniques were applied to cope with the ambient noise, the water depth and the restricted manoeuverability of the boat towing the fish. The results, after the preliminary data process, are the sidescan imagery of the prehistoric settlement, the ancient breakwater, canons, wrecks and a dozen of georeferenced seabed features for further investigation by underwater archaeological reconnaissance.

''No survey is an ultra shallow water survey,
unless you can see your shaddow on the seabed'' P.G.
Image showing the sidescan towfish
deployed by the bow of the boat

Setting up instrumentation
for sidescan sonar survey

Surveying the ancient harbour of Methoni...

MAGNETOMETER SURVEY

A magnetometer survey of the submerged prehistoric settlement and the submerged ancient harbor of Methoni followed the next days, revealing potential submerged artifacts / features, as well as recording and georeferencing existing artifacts / features such as canons and wrecks of the historic period.

The Geometrics G882 marine magnetometer / towfish, Site Searcher Navigation and recording software and the C-Nav 2050G DGNSS were used for the task.

Early in the morning before the magnetometer survey

Towing the Geometrics G882 magnetometer

Ultra-shallow-water magnetometer survey

SEISMIC SURVEY

A shallow water seismic survey followed the second week of fieldwork. This time the objectives were to locate sub-seabed features of archaeological interest and to record the extend of the submerged prehistoric settlement, as well as to record local geological features. Variable Sub-Bottom-Profiler parameters were used for each task, making the survey highly interesting.

The Geoacoustics GeoPulse Pinger Sub-Bottom Profiler, C-Nav 2050G DGNSS, SonarWizMAP+SBP data acquisition system and the HYPACK MAX navigation system were used for the survey, all powered by a 2.6 kW inverter generator. AKTI Engineering (www.aktieng.gr), as a sponsor of The GE.N.ESIS Project, provided the SBP, acquisition and navigation system. A 6.9m RHIB was used for the task, since the weight of instruments and operators was exceeding 650kg.