Corer s 



1. Gravity type -- Phleger 



2. Pi ston type 



a. Kullenburg 



b. Ewing 



Grab samplers 



1. Clamshell snapper 



(Navy Electronics Lab.) 



Z. Mud sampler 



Portable automatic tide 

 gauge 



TIDES 



GRAVITY 



Depth: Unlimited -- deter- 

 mined by length of lower- 

 ing cable used. 



Sediment penetration: 4 ft. 



Depth: Unlimited. 

 Sediment penetration; 6 to 

 12 ft. 



Depth: Unlimited. 

 Sediment penetration: 20 to 

 60 ft. 



Depth: Unlimited. 

 Sediment penetration: Sur- 

 face. 



Same as above. 



Senses tide changes to 

 approximately 0. 1 ft. 



Submarine and surface ship gravimeters 



1. LaCoste and Romberg 



2. Askania (Graf) 

 West Germany 



Geodetic (land) gravimeters 



1. Worden gravimeter 



Range limit: 



245 



