SECT. 1] 



CONTINUOUS REFLECTION PROFILING 



employed. Thus, recordings which display phase relations are often more 

 surely correlated in complex wave trains ; also they can be used to study 

 phase changes in reflection and other transmission processes. 



DEPTH 



IN 



FEET 



200 ^rf 



-1.8 MILES - 



_0UT601NG 

 i PULSE 



» — BOTTOM 

 ECHO 



\ 



SUB-BOTTOM 

 I SEDIMEMT 

 \lNTERFACE 



BEDROCK 

 SURFACE 



Fig. 4. A representative continuous reflection profile over an luieven bedrock surface buried 

 in sediment in Long Island Sound, New York. (After Beckmann.) 



DEPTH IN 

 - FATHOMS 

 (C-- 



800 FM/SEC) 

 10 



ul 



z 

 z 

 < 



Ul 



z 

 z 

 < 



X 



20 



30 



40 



•tZSE*-^ 



DIRECT ARRIVAL 

 BOTTOM REFLECTION 



SECOND BOTTOM 

 REFLECTION 



DIRECT ARRIVAL 

 BOTTOM REFLECTION 



SECOND BOTTOM 



SU8-B0TT0M 

 REFLECTIONS 



Fig. 5. Dual-channel recording made in Vineyard SoLind, Massachvisetts. Channel 1, 

 filtered 2400 c/s high-pass ; channel 2, filtered 75-600 c/s band-pass. 



