WA Margins Reconnaissance Survey (GA-2476) (ESP) - Multibeam Acoustic Backscatter Grid  

Authors / CoAuthors

Siwabessy, J.

Abstract

This resource contains backscatter data acquired during the WA Margins Reconnaissance survey, GA-2476 from October 2008 to January 2009 onboard the RV Sonne as part of the Energy Security Program. Almost 230,000 km² of multibeam bathymetry was acquired over the duration of the survey including all transits. Seafloor features revealed by the backscatter and swath bathymetry have shown that geomorphology of the study areas is diverse. The continental slope of the west Australian margin study areas is characterised by large areas with numerous deeply incised canyons and areas with low-angle slumps and scarps mostly on the upper part of the slope. Other geomorphic features on the continental slope include short escarpments of local extent and small volcanic peaks over the Houtman Sub-basin part of the Perth margin. New bathymetry from the Cuvier Plateau has mapped large volcanic domes, some of them with terraces, ridges, a large previously unmapped valley and two large seamounts (newly named the Cuvier Seamount and the Wallaby seamount). See GA Record 2009/38 (Geocat# 69606) for further details on processing methods.

Product Type

dataset

eCat Id

79138

Contact for the resource

Keywords

• Marine DataBackscatter Grid

( Theme )

• marine environmental baselines

( Theme )

• multibeam

( Theme )

• backscatter

( Theme )

• marine

• WA

Australian and New Zealand Standard Research Classification (ANZSRC)

• Earth Sciences

• Published_External

Publication Date

2014-01-01T00:00:00

Creation Date

Security Constraints

Australian Government Security ClassificationSystem    

Classification - unclassified

Legal Constraints

Creative Commons Attribution 4.0 International Licence    

Access - license

Use - license

Status

Purpose

Maintenance Information

asNeeded

Topic Category

geoscientificInformation

Series Information

Lineage

The backscatter data were processed using CMST-GA MB Process toolbox software. The fully processed backscatter strengths were corrected for transmission loss and insonification area. The process within the toolbox also involved removal of the system transmission loss, removal of the system model, calculation of the incidence angle and removal of the angular dependence. The grid values are basically the average values of the processed backscatter point data within each grid cell of predefined size, normalised to the backscatter strength at an angle of 25 degrees

Parent Information

Extents

[-32.03, -8.45, 104.52, 118.33]

Reference System

Spatial Resolution

Service Information

Associations

Downloads and Links

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Source Information

Processing software: CMST-GA MB Process Survey Name: WA Margins Reconnaissance Survey GA-2476 Vessel: RV Sonne Country: Germany Operator: RF Forschungsschiffahrt GmbH Bathymetric system used: Kongsberg EM120 Year of installation: 2008 Nominal sonar frequency: 12 kHz Number of beams: 191 beams Beamwidth across track: 2 degrees Beamwidth along track : 2 degrees Pulse length: Variable, operator selectable Depth range: up to 6500 m Vessel speed: 8 - 10 knots Start date of survey: 25 October 2008 End date of survey: 19 January 2009 Institution: Geoscience Australia Start port: Singapore End port: Port Hedland Survey leaders: Kriton Glenn (Leg 1), Andrew Heap (Leg 2), Michael Hughes (Leg 3) Data acquired and processed by: Cameron Buchanan, Justy Siwabessy, Michele Spinoccia, James Daniell Grids resolution: 200m Number of grids: 1 This dataset consists of the following files: - Georeferenced colour tif images in 200m resolution, shaded with sun azimuth 45 degrees - ASCII xyz (*.txt) grids in 200m resolution in UTM49S WGS84 - ESRI ascii (*.asc) grids in 200m resolution in UTM49S WGS84 - ESRI Rasters in 200m resolution - KMZ files 104.52 118.33 -32.03 -8.45