(2) the site of the 1961 Experimental Mohole drilling east of 

 Guadalupe Island, Mexico. Subsequent reports will bear 

 the same title except for the area involved; some will be 

 classified under applicable security regulations, but many 

 will be unclassified. For each location there will be 

 references to literature covering NEL acoustics studies in 

 the area. When the present backlog of information has been 

 reported, future information will be reported as it is ob- 

 tained. It is hoped that the series will be of interest and 

 value to persons studying the acoustics or geology of the 

 areas covered. 



REQUIREMENTS FOR A MODEL 



A thorough discussion of the requirements for an 

 ideal geoacoustic model is not possible within the scope of 

 this report. Briefly summarized, they are as listed below. 



1. A detailed topographic chart of the insonified 

 area, based on soundings made by a research-type echo 

 sounder, and with the location of the ship electronically 

 determined. 



2. Sub-bottom layering of the sediments and rocks. 



a. Detailed layering on the order of a few tens of feet. 



b. General layering to several hundreds of meters. 



3. Sediment and rock samples. 



a. Enough sediment and rock samples to define, 

 in detail, the lateral and vertical sediment and rock distri- 

 butions at the surface and within each layer. 



b. Observations of the bottom to note the detailed 

 microrelief and material (biological or mineral) which 

 might litter the sediment surface. 



