ACOUSTIC ATTENUATION IN SEA ICE.

• Main Authors: Langleben,M. P., Pounder,E. R.
• Other Authors: MCGILL UNIV MONTREAL (QUEBEC) MACDONALD PHYSICS LAB
• Format: Text
• Language: English
• Published: 1968
• Subjects: Snow; Ice and Permafrost; Acoustics; (*SEA ICE; MECHANICAL WAVES); (*MECHANICAL WAVES; ATTENUATION); SEA WATER; SIMULATION; RESONANT FREQUENCY; PROPAGATION; TRANSDUCERS; ARCTIC REGIONS; CANADA; Arctic; Canada; Ice; permafrost; Sea ice
• Online Access: http://www.dtic.mil/docs/citations/AD0679627; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0679627

A study is underway of the acoustic attenuation properties of sea ice. The transmitting transducer was driven by a sinusoidal signal whose frequency was swept mechanically over the frequency range 10 to 500 kHz. The suitably amplified signal from the receiving transducer was plotted against frequency on an X-Y recorder. No absolute power measurements were attempted, but the transmission path was reduced by stages and the resulting differences in received power compared. In a second series of laboratory experiments, small transducers were frozen at various positions through the ice sample to permit in situ power measurements. Results of laboratory and field measurements agree quite well on the pattern of attenuation with frequency, although the numerical values differ somewhat between different samples of ice. (Author)