UPSL carried out a detailed and extensive investigation in the two sides of Corinth gulf, in order to scout and detect the potential sites for both a semi-permanent seismic network and small aperture antennas. Finally 50 sites were selected for the network and four sites for the antennas. Main criteria for the selection of the sites of the seismic network were:
- Distance from the planned locations.
- Noise level as low as possible.
- Geological conditions.
- Public power supply if possible.
- Accessibility.
Concerning the sites for small aperture antennas, main criteria were:
- As much as possible plain areas 300 by 300m
- Noise level.
- As homogenous as possible subsurface conditions.
It must be mentioned that considering the hilly morphology of both areas, and the extended private properties of agriculture cultivation, the achievement of this task was quite difficult.
Finally four sites were selected, two on each side of the gulf, and as according to the requirements of WP3, TASK 3.3, two sub-perpendicular seismic profiles were deployed on each site to explore the homogeneity of the subsurface geological conditions. This last action is described in detail in the corresponding section.
The selected sites, after primary selection, were classified according the above criteria in order to select the 38 most proper ones, keeping the rest as alternative solutions. It must be mentioned that the task of preparing these sites with cemented structures for further investigations in the future, forced us to select sites on public places, and if possible avoiding private properties where the owners would be unwilling to allow a permanent use for the site. Thus preferably places were small chapels in the country, backyards of old deserted schools, etc. Although these places were most convenient for the purpose, it took some time to obtain the final permissions due to delay of approval of various particular applications, to the responsible authorities.
UPSL also supervised the site preparation by Landtech Enterprises in order to face any problem that could occur on site, ensuring that the final configuration was convenient to planned task.
Since the first week of September 2001, the seismic network of the 38 Earthdata seismographs was installed and continuously recording till Feb 20, 2002. The visits around the network to control the site and stations and to collect data by shifting the removable hard disks were done in time interval of 10 days. Acting like this the possible not recorded time due to several reasons such us temperature out of range, power supply, damages by animals or else, was optimised.
Two of these three objectives have been achieved beyond what has been proposed for specific tasks, namely (1) deployment of seismic network, (2) data structure and data organisation. These tasks have been considered as first priority in order to achieve an important recovery of seismic data for a dense uniform network and this change in strategy suggested during the first-year kick-off meeting in Paris/France has required more work than expected for data recording and data organisation. The third objective has been accomplished for the velocity reconstruction part while the attenuation still should be performed by GEOAZUR group.
In further European and national collaborations, these datasets will provide certainly other information we have not yet extracted during this project.