TY - JOUR
T1 - Acoustic scattering from mud volcanoes and carbonate mounds
AU - Holland, Charles W.
AU - Weber, Thomas C.
AU - Etiope, Giuseppe
N1 - Funding Information:
This research was supported by the Office of Naval Research in collaboration with the NATO Undersea Research Centre (NURC) under whose auspices the data were collected during experiment campaigns in 1998, 2002 and 2004. The authors express appreciation to Peter Nielsen, Chief Scientist of the Boundary 2002, Boundary 2004 Experiments under the aegis of the Boundary Characterization Joint Research Project, as well as the NURC ocean engineering personnel, the officers and crew of the R/V Alliance and the ITS Tavolara from which the GAS-SCIPACK measurements were performed.
PY - 2006
Y1 - 2006
N2 - Submarine mud volcanoes occur in many parts of the world's oceans and form an aperture for gas and fluidized mud emission from within the earth's crust. Their characteristics are of considerable interest to the geology, geophysics, geochemistry, and underwater acoustics communities. For the latter, mud volcanoes are of interest in part because they pose a potential source of clutter for active sonar. Close-range (single-interaction) scattering measurements from a mud volcano in the Straits of Sicily show scattering 10-15 dB above the background. Three hypotheses were examined concerning the scattering mechanism: (1) gas entrained in sediment at/near mud volcano, (2) gas bubbles and/or particulates (emitted) in the water column, (3) the carbonate bio-construction covering the mud volcano edifice. The experimental evidence, including visual, acoustic, and nonacoustic sensors, rules out the second hypothesis (at least during the observation time) and suggests that, for this particular mud volcano the dominant mechanism is associated with carbonate chimneys on the mud volcano. In terms of scattering levels, target strengths of 4-14 dB were observed from 800 to 3600 Hz for a monostatic geometry with grazing angles of 3-5°. Similar target strengths were measured for vertically bistatic paths with incident and scattered grazing angles of 3-5° and 33-50°, respectively.
AB - Submarine mud volcanoes occur in many parts of the world's oceans and form an aperture for gas and fluidized mud emission from within the earth's crust. Their characteristics are of considerable interest to the geology, geophysics, geochemistry, and underwater acoustics communities. For the latter, mud volcanoes are of interest in part because they pose a potential source of clutter for active sonar. Close-range (single-interaction) scattering measurements from a mud volcano in the Straits of Sicily show scattering 10-15 dB above the background. Three hypotheses were examined concerning the scattering mechanism: (1) gas entrained in sediment at/near mud volcano, (2) gas bubbles and/or particulates (emitted) in the water column, (3) the carbonate bio-construction covering the mud volcano edifice. The experimental evidence, including visual, acoustic, and nonacoustic sensors, rules out the second hypothesis (at least during the observation time) and suggests that, for this particular mud volcano the dominant mechanism is associated with carbonate chimneys on the mud volcano. In terms of scattering levels, target strengths of 4-14 dB were observed from 800 to 3600 Hz for a monostatic geometry with grazing angles of 3-5°. Similar target strengths were measured for vertically bistatic paths with incident and scattered grazing angles of 3-5° and 33-50°, respectively.
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U2 - 10.1121/1.2357707
DO - 10.1121/1.2357707
M3 - Article
C2 - 17225386
AN - SCOPUS:33845356328
SN - 0001-4966
VL - 120
SP - 3553
EP - 3565
JO - Journal of the Acoustical Society of America
JF - Journal of the Acoustical Society of America
IS - 6
ER -