Low frequency acoustic propagation over calcarenite seabeds with thin, hard caps.

Much of Australia's continental shelf consists of a relatively soft limestone called calcarenite, which is variable in geoacoustic properties and covered by a thin veneer of unconsolidated sediment vanishing in some areas. Low frequency underwater acoustic propagation in such environments is st...

Full description

Bibliographic Details
Main Authors: Duncan, Alexander, Gavrilov, Alexander
Other Authors: Terrance McMinn
Format: Conference Paper
Published: Acoustical Society of Australia 2012
Subjects:
Online Access:http://www.acoustics.asn.au/conference_proceedings/AAS2012/papers/p88.pdf
http://hdl.handle.net/20.500.11937/29453
_version_ 1848752807663894528
author Duncan, Alexander
Gavrilov, Alexander
author2 Terrance McMinn
author_facet Terrance McMinn
Duncan, Alexander
Gavrilov, Alexander
author_sort Duncan, Alexander
building Curtin Institutional Repository
collection Online Access
description Much of Australia's continental shelf consists of a relatively soft limestone called calcarenite, which is variable in geoacoustic properties and covered by a thin veneer of unconsolidated sediment vanishing in some areas. Low frequency underwater acoustic propagation in such environments is strongly influenced by the geoacoustic properties of the calcarenite, which typically has a shear speed slightly lower than the sound speed in water. This often results in strong frequency dependence of the acoustic transmission loss with some frequency bands having a much lower transmission loss than the nearby frequencies. In some cases the upper part of the calcarenite consists of a thin (~1m) layer of hard, well-cemented calcarenite overlaying softer, semi-cemented layers. This paper considers the effect that this hard cap has on the acoustic reflectivity of the seabed and on the resulting acoustic propagation at frequencies sufficiently low that the upper, well-cemented layer is thinner than its shear and compressional wavelengths.
first_indexed 2025-11-14T08:14:30Z
format Conference Paper
id curtin-20.500.11937-29453
institution Curtin University Malaysia
institution_category Local University
last_indexed 2025-11-14T08:14:30Z
publishDate 2012
publisher Acoustical Society of Australia
recordtype eprints
repository_type Digital Repository
spelling curtin-20.500.11937-294532017-01-30T13:13:03Z Low frequency acoustic propagation over calcarenite seabeds with thin, hard caps. Duncan, Alexander Gavrilov, Alexander Terrance McMinn calcarenite continental shelf geoacoustic low frequency Much of Australia's continental shelf consists of a relatively soft limestone called calcarenite, which is variable in geoacoustic properties and covered by a thin veneer of unconsolidated sediment vanishing in some areas. Low frequency underwater acoustic propagation in such environments is strongly influenced by the geoacoustic properties of the calcarenite, which typically has a shear speed slightly lower than the sound speed in water. This often results in strong frequency dependence of the acoustic transmission loss with some frequency bands having a much lower transmission loss than the nearby frequencies. In some cases the upper part of the calcarenite consists of a thin (~1m) layer of hard, well-cemented calcarenite overlaying softer, semi-cemented layers. This paper considers the effect that this hard cap has on the acoustic reflectivity of the seabed and on the resulting acoustic propagation at frequencies sufficiently low that the upper, well-cemented layer is thinner than its shear and compressional wavelengths. 2012 Conference Paper http://hdl.handle.net/20.500.11937/29453 http://www.acoustics.asn.au/conference_proceedings/AAS2012/papers/p88.pdf Acoustical Society of Australia fulltext
spellingShingle calcarenite
continental shelf
geoacoustic
low frequency
Duncan, Alexander
Gavrilov, Alexander
Low frequency acoustic propagation over calcarenite seabeds with thin, hard caps.
title Low frequency acoustic propagation over calcarenite seabeds with thin, hard caps.
title_full Low frequency acoustic propagation over calcarenite seabeds with thin, hard caps.
title_fullStr Low frequency acoustic propagation over calcarenite seabeds with thin, hard caps.
title_full_unstemmed Low frequency acoustic propagation over calcarenite seabeds with thin, hard caps.
title_short Low frequency acoustic propagation over calcarenite seabeds with thin, hard caps.
title_sort low frequency acoustic propagation over calcarenite seabeds with thin, hard caps.
topic calcarenite
continental shelf
geoacoustic
low frequency
url http://www.acoustics.asn.au/conference_proceedings/AAS2012/papers/p88.pdf
http://hdl.handle.net/20.500.11937/29453