APAALSE - Paper - Caris

Figure 13: This figure shows the potential UNCLOS Article 76 area of approximately 40,504
km² (red filled) based on the coarse-gridded sediment data.
Survey Planning
It has been noted that several East-West prominent linear Fracture Zones are present and very
well documented in this transform margin setting. This is critical from an analysis point of view
and for planning purposes. If these linear trends are seen to “pop through” the sediments on the
seabed, the continuity of the sediment plume seaward of the FOS, as required by CLCS, cannot
be established.
Due to these uncertainties, a multi-variate approach to seismic data planning was adopted. Two
seismic survey plans have been suggested. Plan A consists of 10 proposed lines spaced 50 M
apart with a total of 4,189 km. Survey plan B consists of 20 proposed lines, spaced at 30 M with
a total of 6,529 km. These plans were contingent on the continuity of sediments and were
designed such that the survey could be called off after a minimum of 3,777 km. These plans were
then run by Prof. Karl Hinz, courtesy the Commonwealth Secretariat, who felt that only three
seismic lines, each 300 km long, from the Ghanaian slope into the eastern potential extension
area and a maximum of three tie-lines, each about 110 km long, i.e. a total of about 1,250 km,
are sufficient (Figure 14).
14