. The Earth beneath the sea : History . Fig. 1. (a) Continuous profiling for normal incidence reflections, (b) Procedure for oblique reflection profiles. The echoes are then converted to electrical signals and fed ultimately to a graphic recorder like those commonly used in echo-sounding. (The basic operation is illustrated in Fig. 1.) Both single-frequency and broad-spectrum sound sources have been used. Either are short pulses of sound radiated on a precise schedule that is controlled by the graphic recorder. Since different [MS received July, 1960] 47

---

Size: 3200px × 1562px
Photo credit: © The Bookworm Collection / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: ., bookcentury1900, bookcollectionbiodivers, booksubjectoceanbottom