This document reports the activity during two cruises in the Tyrrhenian Sea, that were planned to achieve the full bathymetric coverage of the basin, along with other important geophysical information. The Project, coordinated by E.Bonatti, was funded by CNR and other Scientific and Governmental Italian Agencies. To obtain this goal, the Institute of Marine Geology used most of its organizational, technical and scientific skill, in the use of modern swath bathymetry systems.
Since 1991 IGM started to work with multibeams. Several cruises were run with the russian ship A.N. Strakhov of GIN in the Equatorial and South Atlantic ([1],[2]). The bathymetric data were acquired with a medium resolution instrument (HOLLMING 626). During November 1995 a cruise around the Aeolian Islands with the ship J.Charchot provided very good quality data by SIMRAD's EM12 and EM1000 [5]). At the end of 1995 R/V Gelendzhik of CGGE (Russia) installed a high resolution multibeam (SIMRAD EM12-120S) and was chartered to IGM for a 6 months period during 1996, for works in the Atlantic Ocean (at the Bouvet Triple Junction and at the Romanche Fracture Zone, [3],[6],[4]), and in the Tyrrhenian Sea (first cruise, september and october 1996, TIR96). The operation was possible because of joint PNRA/ENEA fundings, that facilitated the contract and provided 4 months of work at sea in the Atlantic Ocean with minimum transits.
In 1998 R/V A.N.Strakhov installed a SIMRAD EM12-120S, owned by ELETTRA, a TELECOM ITALIA company, who signed a contract with ship owners and IGM, that had the opportunity to use the vessel for two months per year. During February and March 1999 we had the second cruise in the Tyrrhenian Sea (TIR99).
Whilst the Thyrrenhian project was in the pipeline, IGM started a very good cooperative relationship with the Hydrographic Institute of the Navy (IIM), that pushed into the project the multibeam and singlebeam data acquired by their ships in the Aeolian and Sicilian Areas, along with very important data for datum shifts. The integration of these datasets was somehow challenging, because of the different gridding system and datum. More than the simple exchange of data and personnel, IIM offered also professionalism in hydrography and cartography, and the possibility of important future cooperation.
The project is still underway for the final processing of the data, expecially magnetics, gravimetry and seismics.