GP-Sep-Oct 2013

Geophysical prospecting September – October 2013.
Underwater Archaeology Bathymetric and Side Scan Sonar Surveys Sozopol – Sinemorets / ”Silistar”
Underwater Bathymetric and Side Scan Sonar Survey for Archaeology
Sozopol – Sinemorets, September - October 2013
September - October 2013
Areas: Sozopol, Kiten, Ahtopol, Sinemorets, Silistar
Survey team members:
Dr. Atanas Orachev, Dragomir Garbov,
Garbov Hristina Angelova, M.Sc. Kiril Velkovsky,
Velkovsky Vesselin
Draganov, Dr. Naiden Prahov, Peter Petrov
Centre of Underwater Archaeology
September – October 2013
K. Velkovsky
Geophysical prospecting September – October 2013.
Underwater Archaeology Bathymetric and Side Scan Sonar Surveys Sozopol – Sinemorets / ”Silistar”
September - October 2013 the Centre of Underwater Archaeology (CUA) Sozopol has launched a
remote sensing survey in the area of sought Bulgarian black sea.
The survey incorporated bathymetrical and side scanning monitoring of the studied areas on the
aquatory of Black Sea from the cost line to nearly 40 m deep iso-bath.
The objectives of the survey have been:
−
−
−
−
Setup and test operational a newly acquired equipment by CUA and setup a methodology
of underwater remote sensing surveys especially for archaeology;
Collect data for areas where previously surveys have been not made at the blanked fields
on the map;
Discover and locate new objects potentially interesting for archaeology;
Receive detail information
mation for the sea bottom geological structures in order to help for more
clear hypothesis of the development of cost line in the pass;
The survey has been lunched with the support of the Ministry of the Culture Bulgaria.
A bathymetry and side scans have been conducted simultaneously using a boat along planed in
advance tracks in the studied areas.
Fig.01. Picture with
The covered from the survey areas are:
the survey areas
− Sozopol, West Bay and the area between
st. Kirik and st. Ivan
− Kiten area starting from the cape of
Primorsko from North, to bay of Oasis on
south side.
− Ahtopol North Bay
− Sinemorets south bay to “Silistar” bay
− Boat tracks
racks between Ahtopol Sinemorets
− Bay of Silistar
For the time of the survey have been covered
areas of over 27 sq. km. The received side scan
tracks are over 260 km in more than 150 lines.
Area
Number of
profiles
Kiten
Ahtopol
Ahtopol-Sinemorets
Sinemorec South
Silistar
Total:
Centre of Underwater Archaeology
September – October 2013
79
26
4
31
11
Length of the
profiles
182.7
13.0
22.5
40.0
11.0
268.20 km
Area
measured
17.50
2.60
3.50
3.05
0.51
27.16 km2
K. Velkovsky
Geophysical prospecting September – October 2013.
Underwater Archaeology Bathymetric and Side Scan Sonar Surveys Sozopol – Sinemorets / ”Silistar”
Used equipment
The used equipment for the survey has been:
−
−
−
Bathymetry has been made with BBT-Flamingo
BBT Flamingo echo sounder with integrated DGPS
system.
Side scanning sonar StarFish 450H hull-mounted
mounted seabed imaging system for sea bed
scanning.
As tracking system has been used Trimble DGPS system. The signal from the DGSP has
been split for precise online navigation of the boat and to coordinate the side scan.
Fig. 02. Equipment schematic connections.
Fig. 03. Data flow.
Used methodology:
After several tests, considering the tasks and the
specific of the areas the surveys have been
conducted along in advance planed tracks, in a
perpendicular direction to the shore.
In major cases the tracks have been directed in
east-west or opposite directions.
Fig. 04. Side scan lines Kiten – Primorsko.
Primorsko
The distance between the tracks has been 80
meters to guarantee coverage of 50% to 70% of
the side scans from two tracks. The methodology allows objects in the middle zone between the
tracks to be seen on the sonograms from two sides.
Along the shore, in shallow waters the surveys have been conducted in free tracks depending from
the specific of the area,, but closely to the shore.
The tracks have been different length until deepness of 25-30 m has been achieved. In
I several
cases as control has been reached deepness of 40-45
40
m.
Along the free boat tracks to the destinations have been collected records in order to be used as
additional information and as control measurements.
Centre of Underwater Archaeology
September – October 2013
K. Velkovsky
Geophysical prospecting September – October 2013.
Underwater Archaeology Bathymetric and Side Scan Sonar Surveys Sozopol – Sinemorets / ”Silistar”
Received results bathymetry:
Based on the received data from the echo sounder Flaming BBT preliminary bathymetrical maps
are created. The maps are available in WGS84 and 1970 coordinate systemss.
The results are available as greed and data files, JPG or GeoTIFF files and KMZ files for Google
Earth.
Fig. 05. Bathymetrical map Kiten area: bay Primorsko
south to “Oasis” bay.
Fig. 06. Bathymetrical map of Ahtopol - North
bay.
Fig. 07. Bathymetrical map of the Sinemoret
area.
Fig.08. Bathymetrical map and located objects
by side scanning in the area of SozopolSozopol
Chernomorets bay.
Centre of Underwater Archaeology
September – October 2013
K. Velkovsky
Geophysical prospecting September – October 2013.
Underwater Archaeology Bathymetric and Side Scan Sonar Surveys Sozopol – Sinemorets / ”Silistar”
Received results from side scans:
For all areas preliminary mosaics are created. The results are available in form of GeoTIFF or
KMZ.
Over 700 potential locations or individual objects on the sea bottom have been selected for further
underwater conformation. Locates have been selected based on following measures: Objects
which does not fit the context of the surrounding exterior or present some logic of the position;
Objects which have specific shape or produce extremely powerful echo signal.
It is upcoming task the list and the information to be precisely evaluated in a short list with
potentially interesting objects or locations from archaeological point of view.
Fig.08 Arch object on the sea bottom – the structure looks like it is
constructed from separate stones and does not fit the structure of
surrounding rocks.
Fig.09. Arch object, 4-5 m deepness. The shape is
similar to board of ship. The size of the object is
around 14 m length.
Fig.10. Object with rectangular shape in the sand lies
6 m deep on the sea bottom.
The post processing is ongoing and new results will be available.
K. Velkovsky
Centre of Underwater Archaeology
September – October 2013
K. Velkovsky