844 EXPLORATION GEOPHYSICS 



owners and lessees for the necessary work on the land. The permit man 

 also makes agreements regarding the condition in which the land and fences 

 must be left. Sometimes the final decision as to exact location of shot-holes 

 and seismometer stations is not made until after permits are obtained. The 

 surveyors then locate these points and mark them with stakes ; the stakes 

 are numbered and their location plotted on maps. The points are now 

 ready for the drillers who must drill the holes to depths that have been 

 determined from experience in the area or in similar areas. Next, the 

 shooting and recording operations take place, preferably soon after the 

 holes are drilled. 



TABLE 24 



GENERAL DIVISION OF DUTIES OF MEMBERS OF SEISMIC CREW 



Party Chief Field supervision of all operations. 



Interpretation of field data. 

 Contact man between geophysical and geological departments. 



Assistant Chief Assistant to Party Chief and next in charge. 



Computer Computation of results and plotting. 



Operator Responsible for recording truck operation and in charge of 



crew while on field. 



Assistant Operator Assistant to operator. 



Shooter Responsible for explosives, loading, and shooting operations. 



Assistant Shooter Assistant to shooter. 



Driller Responsible for drilling of shot-points and for drilling 



equipment. 



Assistant Driller Assistant to driller. 



Laborers General field operations such as digging of shallow holes for 



seismometers, handling of cables. Helpers to drillers and 

 shooters. 



Permit Man Right of way and shooting permits. 



Surveyor Location of seismometers and shot-holes. 



Rodman Assistant to surveyor. 



The basic seismic operations are performed by two units : namely, the 

 shooting unit and the recording unit. The procedure in the field is managed 

 by the operator who is also responsible for the recording equipment. The 

 recording unit consists of the recording truck and three or more men, at 

 least one of whom, besides the operator, is sufficiently familiar with the 

 equipment to assist in its maintenance. The shooting unit usually consists 

 of two or more men and one truck. The head of the unit, the shooter, is 

 responsible for his equipment, for efficient loading of the holes, and for the 

 handling of explosives by his unit according to the legal and safety 

 regulations. 



After the seismometers of the recording truck unit are disposed and 

 circuits checked, the recording equipment is ready for operation. By this 

 time the shooter generally has loaded the hole with a charge at a depth 



