3D Visualization and Analysis of
Topographic and Geologic Oceanographic
Data in the NW Aegean Sea
A. Karageorgis, P. Drakopoulou & Chr. Anagnostou
The EU MAST-III ELOISE Metro-Med project
(Contract No: CT 960049)
Collects data from the fields:
• Physical
• Geological
• Biological and
• Chemical Oceanography
In an effort to organize, analyze, compare and finally to explore
the data set, we have utilized the Arc/Info GIS platform for the
development of an application named “Metro-Med GIS”
Metro-Med Multidisciplinary Cruises
1998
1997
The Working Area
Marine area : Thermaikos Gulf & Sporades basin
in NW Aegean Sea
(39o 00΄N - 22o 30΄E, 40o 40΄N - 24o 30΄E)
Drainage basin : study the marine area as an integrated
system with the surrounding land,
since terrestrial input in fresh water,
sediments, nutrients, pollutants is of
major importance.
The Working Area
The Working Area
Data projection ...
Greek Geodetic Reference System 1987:
• Transverse Mercator projection
• central meridian λo = 24o
• scale’s coefficient = 0.9996
• constant 500,000 is added to the x-axis values
* The reference points use for the data transformation,
produced an RMS (Residual Mean square) Error
between 0.002 and 0.017
The area under investigation was separated
in three zones ...
The cartographic data base
comprises the following categories - layers of
information:
• Bathymetry
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Hypsometry
Hydrography
Political - Administrative borders
Road Network
Urban Area
The DEM of the whole area ...
Metro-Med Digital Bathymetric Map
of the Thermaikos Gulf and the Sporades Basin
1500
1400
1300
1200
1100
1000
900
800
700
600
500
400
300
200
150
100
90
80
70
60
50
40
30
20
10
0
-100
meters
Shelf
Area Volume
(km2)
(km3)
5,350
430
Basin
5,250
3,570
Total
10,600
4,000
Factors controlling SPM distribution:
• riverine supply
– proximity to the sources
– water circulation
– bottom topography
• Thessaloniki city supply
• stratification
Particle transport and deposition
• transport along the western coast (SE)
• resuspension and deposition mechanisms
closely related to the distance from the river
mouths
• absence of detached layers towards the basin
• shelf acts as a sediment trap
Conclusions
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SPM major sources are the rivers Axios, Aliakmonas and Pineios
SPM input is high only during the “wet” seasons
SPM distribution follows the dominant cyclonic cirulation
SPM settles in the shelf
SPM is mainly terrigenous
Sediments distribution follow in general the bathymetry
Sands in the eastern and central part
• lack of input
• circulation patterns
• Silt deposition in fron of the river mouths
• Clay deposition in the basin
• Resuspension possibilities in the western part