OBJECTIVE 



The overall objective of the Project is to assess the impact of under- 

 water noise created by offshore oil drilling and production operations on 

 marine mammals along the outer continental shelf of the U.S. and propose 

 mitigating measures if necessary. 



The measurements described in this report were directed at three goals: 



(1) To broaden the data base on underwater noise radiated by 

 offshore oil operations by gathering data on a large number 

 of drilling and production platforms. 



(2) To determine the general geographic distribution of 

 underwater noise in the area off Santa Barbara, California, 

 to provide data which might be correlated with the migration 

 pattern of the California Gray whales which traverse this area. 



(3) To determine the variability with time over a period of five 

 days for a platform engaged in offshore drilling. 



APPROACH 



(1) Magnetic tape recordings were made of the underwater noise near 



each of fourteen platforms using a hydrophone-pre amplifier-filter- 

 recorder package especially designed for broad frequency range, 

 high sensitivity and low noise. This system is the one used in 

 all field surveys conducted on this project since June 1980. 

 Recordings were analyzed for spectrum content in the NOSC Intelligent Data 

 Handling and Control System (IDHACS) facility. Both the recording 

 system and the IDHACS facility are described in Ref. 1. 



F-3 



