Ice Vibrations on the Arctic Channel.

• Main Author: Kutschale, H.
• Other Authors: COLUMBIA UNIV NEW YORK LOWELL MEMORIAL LIBRARY
• Format: Text
• Language: English
• Published: 1996
• Subjects: Acoustics; *UNDERWATER SOUND SIGNALS; *UNDERICE; COMPARISON; SIGNAL TO NOISE RATIO; TOPOGRAPHY; HYDROPHONES; ARCTIC REGIONS; ACOUSTIC CHANNELS; GEOPHONES; GRAZING ANGLES; Arctic; Arctic Sound
• Online Access: http://www.dtic.mil/docs/citations/ADA317278; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA317278

Differences in signal-to-noise ratios between hydrophones and geophones were measured as a function of signal grazing angle with level ice and signal frequency. The frequency distributions in the differences clearly show two groupings. One group represents waves traveling in the Arctic sound channel with grazing angles less than 20 degrees and the other group represents waves with large grazing angles beyond 70 degrees such as long-range mantle P and S waves created by earthquakes and explosions. In the band 8 Hz to 20 Hz in SOFAR signals, T-phases, and topographic echoes the hydrophones at depths near 40 m in the water of the channel record waves about 7 dB stronger in average signal-to-noise ratio compared to vertical geophones on the ice. At large grazing angles near 75 degrees the relative performance between the two sensors reverses, with the average signal-to-noise ratio recorded by the vertical geophones about 3 dB better compared to that recorded by the hydrophones.