Data 



1. Source Level (SL)--Three Sources . At this writing, source level 

 analysis has been performed on three drilling rigs: SSD-1, semi-submersible 

 drilling rig, Lower Cook Inlet, Alaska; SSD-2, semi-submersible drilling rig, 

 Baltimore Canyon, Atlantic; and FDP-1, fixed drilling and production platform, 

 Santa Barbara, California; and three production only platforms: FP-1, fixed, 

 4-legged production platform. Upper Cook Inlet, Alaska; FP-2, fixed, 3-legged 

 production platform. Upper Cook Inlet Alaska; and MMIP, man-made island, 

 production, Santa Barbara, California. The noise measured in the water from 

 FDP-1 and MMIP was so low that the measurements are considered doubtful and 

 are being repeated. Noise radiated from SSD-1 and SSD-2 and FP-1 and FP-2 was 

 substantially above the ambient background noise, and contained prominent low 

 frequency tonal components of the t3^e expected to be detectable by whales. 

 Figures 7, 8, and 9 show the third-octave band spectra measured by NOSC for 

 the three platforms selected as sources for this study. In view of the 

 similarity between the two drilling semi-submersibles (one in lower Cook 

 Inlet, Alaska, and the other off Baltimore Canyon in the Atlantic) source 

 level data for the Alaskan rig only will be used. Table 1 shows source levels 



G-28 



