Use of high-frequency (3.5–12 kHz) echograms in the study of near-bottom sedimentation processes in the deep-sea: A review

Damuth, John E.

doi:10.1016/0025-3227(80)90051-1

Cited by 332 publications

(231 citation statements)

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“…These large hyperbolic echoes are suggestive of basement highs or outcrops as was also suggested by Damuth (1980) and Lee et al (2002). These echo types do not depend on the hydrodynamic conditions of the environment, being exclusively structurally controlled.…”

Section: Echo Character Type IIsupporting

confidence: 72%

“…Hollister & Heezen, 1972;Damuth, 1975;Embley, 1976;Flood, 1980;Jacobi & Hayes, 1992;Baptista Neto et al, 1996;Reddy & Rao, 1997;Dowdeswell et al, 1997;Zaragosi et al, 2000;Hong & Chen, 2000;Quaresma et al, 2000;Lee et al, 2002). The types and distribution of the echo-character can be used as basis for the interpretation of depositional and erosional processes, since the echo types are mainly controlled by surface topography, subsurface geometry and sedimentary texture of the superficial and sub-superficial sediments and rocks (Damuth, 1975(Damuth, , 1980Embley, 1976;Damuth & Hayes, 1977).…”

Section: Introductionmentioning

confidence: 99%

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Distinctive sedimentary processes in Guanabara Bay - SE/Brazil, based on the analysis of echo-character (7.0 kHz)

Catanzaro¹,

Neto²,

Guimarães³

et al. 2004

Rev. Bras. Geof.

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ABSTRACT. Guanabara Bay bottom sediments and seabed characteristics were analysed using high-resolution (7 kHz) sub-bottom profiles associated with particle size analyses of 92 bottom sediment samples. Eight types of echo-characters were identified revealing the strong relation with the particle size distribution. Sandy bottom areas presented strong echo reflections, without sub-bottom penetration (Echo types I and III), while in muddy areas sub-bottom reflections showed the acoustic basement delineating buried sugar-loaf hills and infilled-valley features (Echo type IV). The presence of shallow gas within the sediments is indicated by acoustic blanket and a series of bottom-multiple reflections (Echo types Va and Vb). Erosion by bottom currents and artificial mechanical dredging are suggested by truncations of sub-bottom reflections and a wrinkled seabed surface (Echo types VI and VII). Crystalline basement outcrops on the seabed are recognized by multiple or single hyperbolae with varying elevations above the bay bottom (Echo type II).

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Section: Echo Character Type IIsupporting

confidence: 72%

Section: Introductionmentioning

confidence: 99%

Distinctive sedimentary processes in Guanabara Bay - SE/Brazil, based on the analysis of echo-character (7.0 kHz)

Catanzaro¹,

Neto²,

Guimarães³

et al. 2004

Rev. Bras. Geof.

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“…Geophysical techniques provide continuous bottom mapping including bathymetry and sediment sublayers for substantially larger areas in comparison with traditional point-based sampling methods. In freshwater environments, acoustic signals are most extensively applied to image bathymetry and sediment sublayers (Damuth, 1980;Garcia et al, 2004). By examining the contrast of mechanical impedance (product of acoustic speeds in medium and bulk density of medium) and acoustic reflectivity, one can delineate the interface of different mediums, such as water-sediment, sand-clay layers or soft and hard patterns over lake floors (Nitsche et al, 2004;Lin et al, 2010).…”

Section: Methodsmentioning

confidence: 99%

Response of bottom sediment stability after carp removal in a small lake

Lin

2013

Ann. Limnol. - Int. J. Lim.

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-This study combined several features of acoustic and electromagnetic (EM) waves-based devices including sub-bottom profiler (SBP), side-scan sonar (SSS) and ground penetrating radar (GPR), and in situ sediment data to study responses of bottom sediments after carp removal in Lake Wingra. In 2007, i.e., before carp removal, macrophytes only grew to a water depth of 2 m. Meanwhile, GPR data showed no visible sublayer in vegetated regions, while SBP data revealed a loose and fluffy sediment layer in unvegetated regions, easily affected by wave or current motions. The field data showed that suspended sediment concentrations (SSC) were much greater in unvegetated regions than those in vegetated regions during a one-day wind event, and the resuspended sediments could remain suspended in the water column for two days. In 2009, i.e., after more than half (51%) of carp were removed, the fluffy sediment layer recognized by SBP became thinner or even disappeared, and both SBP and SSS results showed that submerged macrophytes started growing in deeper water. In situ sediment data presented that bulk sediment density and critical shear stress became greater, and bottom sediments consolidated and were harder to be resuspended. Secchi depth collected between 2008 and 2010 was greater than that in the previous 10 years, indicated clearer water state. In short, the fluffy sediment layer because of carp activities may be the main source for suspended sediments to deteriorate water quality. Removal of carp is crucial for stabilizing bottom sediment and improving water clarity in this small lake.

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“…8). Seismic characteristics such as amplitude, reflection continuity, external shape, and frequency allow us to infer depositional processes operating in the study area (Damuth, 1980). Unit CM is mound-shaped, and shows highly irregular internal reflection patterns with occasionally strong discontinuous internal reflections.…”

Section: Seismo-stratigraphic Analysismentioning

confidence: 99%

Geodetic and geological evidence of active tectonics in south-western Sicily (Italy)

Barreca

Bruno

Cocorullo

et al. 2014

Journal of Geodynamics

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a b s t r a c tIntegrated geological, geodetic and marine geophysical data provide evidence of active deformation in south-western Sicily, in an area spatially coincident with the macroseismic zone of the destructive 1968 Belice earthquake sequence. Even though the sequence represents the strongest seismic event recorded in Western Sicily in historical times, focal solutions provided by different authors are inconclusive on possible faulting mechanism, which ranges from thrusting to transpression, and the seismogenic source is still undefined. Interferometric (DInSAR) observations reveal a differential ground motion on a SW-NE alignment between Campobello di Mazara and Castelvetrano (CCA), located just west of the maximum macroseismic sector. In addition, new GPS campaign-mode data acquired across the CCA alignment documents NW-SE contractional strain accumulation. Morphostructural analysis allowed to associate the alignment detected through geodetic measurements with a topographic offset of Pleistocene marine sediments. The on-land data were complemented by new high-resolution marine geophysical surveys, which indicate recent contraction on the offshore extension of the CCA alignment. The discovery of archaeological remains displaced by a thrust fault associated with the alignment provided the first likely surface evidence of coseismic and/or aseismic deformation related to a seismogenic source in the area. Results of the integrated study supports the contention that oblique thrusting and folding in response to NW-SE oriented contraction is still active. Although we are not able to associate the CCA alignment to the 1968 seismic sequence or to the historical earthquakes that destroyed the ancient Greek city of Selinunte, located on the nearby coastline, our result must be incorporated in the seismic hazard evaluation of this densely populated area of Sicily.

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Use of high-frequency (3.5–12 kHz) echograms in the study of near-bottom sedimentation processes in the deep-sea: A review

Cited by 332 publications

References 50 publications

Distinctive sedimentary processes in Guanabara Bay - SE/Brazil, based on the analysis of echo-character (7.0 kHz)

Distinctive sedimentary processes in Guanabara Bay - SE/Brazil, based on the analysis of echo-character (7.0 kHz)

Response of bottom sediment stability after carp removal in a small lake

Geodetic and geological evidence of active tectonics in south-western Sicily (Italy)

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