to the presence or recent presence of animals. Shell 

 fragments of deceased mollusks were found strewn about 

 the sea floor. Artifacts of man, such as discarded metal, 

 paper, glass containers, and other materials have also 

 been viewed on the sea floor. 



DIVE NO. 52 



Approaching the bottom at 72 feet, the sea floor was 

 first seen at a range of approximately 2 5 feet. Heavy con- 

 centrations of suspended material and living forms res- 

 tricted visibility to approximately this range. On landing, 

 a small cloud of sediment was forced into suspension by 

 the water displaced around the descending sphere. The 

 cloud was quickly dispersed and carried out of the viewing 

 area by the water current present. A check of the time 

 required for suspended particles to drift across the 10- cm 

 diameter of the inner frustule indicated a water current 

 flow of 5 cm /sec. During the time the bathyscaph was 

 fixed on the sea floor, the suspended matter was seen to 

 include not only inanimate particles but a myriad of bio- 

 logical forms that included medusae, arrow-worms, 

 ctenophores and mysids. 



Microtopographic relief such as sculpturing, furrow 

 trails, mounds, and depressions appeared at a minimum 

 despite the wide variety of living forms present. However, 

 as the bathyscaph moved across the sea floor, a changing 

 panorama of microrelief was observed that included such 

 features in varying degree and quantity. The largest 

 feature seen was a depression 6 feet across and 2 feet deep. 

 The channel (?) extended beyond the visual range made 

 possible by the external illumination. It was not bordered 

 by levees despite the rather steep slope bordering each 

 side of the long depression. Sediment appeared to be at 

 a maximum angle of repose. However, the condition of 

 the slope indicated a prolonged period of exposure to the 

 velocity of currents present and sedimentation of particles 

 on the sea channel slopes. 



Artifacts of man observed included two tin cans, an 

 old shoe, and a sheet of newspaper. These artifacts all 

 rested on the surface of the sea floor. Settling into the 

 sediments appeared to be at a minimum. No scouring 

 about the artifacts had been effected by the water current 

 flow present. 



13 



