This data set consists of processed seismic reflection data for line 01AGS-NY1 from the 2001 Northern Yilgarn seismic survey (L154), Western Australia. Line 01AGS-NY1 commenced in the Yilgarn Craton (Leonora) and extended to the east into the Officer Basin (east of Lake Yeo). The data were acquired by the Australian National Seismic Imaging Resource (ANSIR) using vibratory sources at a nominal 60 fold coverage. The seismic data are provided as SEG-Y files of stack and migrated data to 4 seconds and 18 seconds two-way time, at a sample interval of 4 milliseconds. CDP range is 1985 to 20860 with 20 metre CDP interval. SEG-Y header information, CDP coordinates as eastings and northings, and a pdf image of the migrated 18 second seismic section are also included. The line, migrated section images and further information on this data can be obtained from the <a href="http://www.pmdcrc.com.au" target="_blank">pmd*CRC</a> website.

No abstract available

Seismic stack data available in SEGY format. Data were acquired under the Continental Margins Program in 1985 and processed in-house at AGSO. Hardcopy sections also available on request

TBA

The Bureau of Mineral Resources has again'extended its geophysical programme in the search for oil to the continental shelf area of Australia by carrying out a combined gravity, and seismic survey in the Timor Sea/Joseph Bonaparte Gulf area of northwest Australia. The survey investigated the capabilities of the surface marine gravity meter for reconnaissance gravitywork at sea, and the penetration and quality of seismic reflections obtainable using a spark discharge source consisting of an array of electrodes. The possibility of operating the two methods simultaneously was also investigated. The seismic reflection sections recorded were much better than expected, with good-quality reflections being recorded to 1.6.sec. the gravity meter and seismic'equiPment were operated simultaneously at boat speeds of 8 to 9 miles per hour. The-seismic results have shown that a large Permian and Mesozoic sedimentary basin exists in the Joseph Bonaparte Gulf and extends to the north and north-west into the Timor Sea. It is an offshore extension of the Bonaparte Gulf Basin, and contains at least 10,000 feet of post-Permian sediments. .Although the trends of the gravity anomalies agree with the general shape of the basin as defined by the seismic results, a large positive anomaly occupies the central deep part of the basinand does not seem to be related to basement relief.

The Bureau of Mineral Resources has carried out two large scale reconnaissance marine geophysical surveys in the Joseph Bonaparte Gulf and Timor Sea areas in 1965 and 19670 It is proposed to continue this geophysical reconnaissance to the south over the northwest continental shelf from Ashmore reef to Barrow Island. 16 000 line miles should be covered in 3 months on mainly east-west lines 9 nautical miles apart. The boat speed will be about 10 knots. The survey will be done by Ray Geophysics (Australia) Pty Ltd under contract.

Ice thickness measurements were made in 1961 by seismic methods on a line southward from S-2, a glaciological station 50 miles east-south-east of Wilkes Base, Antarctica. The traverse constituted the first year's work of a three-year programme. The results showed that the rock underlying the ice dips below sea level at a point between 20 and 40 miles south of S-2. It remains below sea level at all the locations occupied to the south, as far as 280 miles south of S-2, where the rock surface is again above sea level. The main feature is a valley disclosed in the rock formation between 40 and 80 miles south of S-2. Midway between these two points the rock lies at approximately 7500 ft below sea level. The positions of the Totten Glacier and the John Quincy Adams Glacier suggest that the valley may have been responsible for their formation.

During 1963, the Australian National Antarctic Research Expeditions carried out two over snow traverses in the vicinity of Wilkes Station, Antarctica. The Autumn Traverse reached a point about 100 miles east of Wilkes and the Spring Traverse a point about 300 miles south-east of Wilkes. Surface elevations were measured by barometric methods and ice thicknesses were determined by gravity and seismic techniques. Magnetic measurements were made and borehole temperatures were taken. Experiments were conducted to devise means of improving the quality of the seismic reflection records. The optimum frequency range for the filter settings was found to be 90-215 c/s. A hand-drilled 4-ft shot-hole was adequate in the coastal or low plateau regions within 150 miles of Wilkes. Further inland, a shot hole of at least 30-ft depth was required. The optimum charge size was one pound of explosive.

At the request of the Australian Atomic Energy Commission, the Bureau of Mineral Resources, Geology & Geophysics conducted a seismic refraction survey on the site chosen for construction of a nuclear power station. The purpose of the survey was to determine the foundation conditions at the site and the properties of the rocks in relation to excavation methods and support of the proposed structures. The bedrock of the area consists of Permian sandstone (Jervis Bay Sandstone) overlain in places by unconsolidated Quaternary beach and dune sands. During the seismic work it was found that the sandstone beds have a relatively wide range of seismic velocities; often a higher-velocity bed overlies a lower-velocity bed, and this makes seismic refraction work difficult and less accurate. This is confirmed by laboratory measurements of seismic velocities on drill cores. Thin beds of higher- and lower-velocity sandstones occur, some too thin to be resolved by the seismic method. The seismic profiles presented must be considered bearing in mind these difficulties, Haterial sufficiently consolidated for foundations is shallow, and the seismic velocities indicate that some blasting will be necessary to excavate to the desired depth of 10 feet above mean high water level.

During the period September to December 1970 the Bureau of Mineral Resources (BMR) carried out an experimental airborne seismic survey in swamp and other areas of the Northern New Guinea Basin, which are inaccessible to conventional seismic land operations. A helicopter was used to place explosives, shooting equipment and geophones connected to sonobuoy transmitters into position on the ground. Seismic signals are received from the sonobuoy transmitters and recorded on a conventional recording system mounted in an aircraft flying over the seismic field set-up at the time of each shot. Preliminary investigations indicated that the airborne seismic technique is practicable and operationally feasible for use in the swamp areas of the Northern New Guinea Basin.