The Haydn airborne laser fluorosensor (ALF) survey is located in the Vulcan Sub-basin, Timor Sea. The survey was flown in two sorties on the 2nd December 1996. Sixty-five lines were acquired at 400 m spacing in a NW-SE orientation with a total of about 550 square kilometres acquired. Seventeen lines were acquired at 1200 m spacing in the orthogonal NE-SW direction. The NW-SE lines were about 21.35 km long while the NE-SW lines were about 26 km long. Many types of noise were found on the ALF records and these were rejected during the manual checking phase of fluor selection.Of the 1,529,484 spectra recorded, only 21 were interpreted as having confident fluors. No significant fluorescence clusters were observed. Only 4 fluors were found with a F/R ratio above 0.30.

The Browse Basin airborne laser fluorosensor (ALF) MkII survey was flown in 1989. The MkII system used a 308nm laser wavelength, which is longer than the 266nm used in the later MkIII system. The Raman peak wavelength is 344nm (293nm MkIII) and the fluorescence region is 370nm to 580nm (320nm to 580nm MkIII). 32 lines were acquired at about 5,000m spacing in a NNE-SSW orientation and a flying height of 100m. A total of 133,125 spectra were collected at an average spacing of 16m to 25m. About 2,270 km of line data were acquired. Each recorded spectrum is the average (or sum) of ten detected spectra. The averaging was done to reduce the data recording rate, which was limited by the available hardware. The survey was interpreted using the ALF Explorer application that consists of a database linked to a set of data processing, analysis and display modules. A total of 776 fluors were interpreted out of the 133,125 recorded spectra. The fluorescence response over most of the survey area consisted mostly of relatively low confidence fluors. High intensity fluors are located over Scott Reef but are probably caused by the reef material fluorescing.

The Bonaparte Basin airborne laser fluorosensor (ALF) MkII survey was flown in 1989 by BP over the northern Petrel Sub-basin, Darwin Shelf and Malita Graben. The survey was designed to detect natural oil seepage over a region of the Bonaparte Basin, Australia, in an effort to refine the petroleum prospectivity assessment. The survey was acquired in two separate parts. The larger southwest part extends up to 230km east to west and up to 240km north to south. The northwest part extends about 120km east to west and an average of 100km north to south. A total of 872,412 fluorosensor spectra were recorded. This report presents a re-interpretation of the BP data by Signalworks Pty Ltd using the ALF Explorer software. A total of 1,689 fluors were picked out of the 872,412 recorded spectra in the final interpretation. This is an average fluor density of 1.94 fluors per thousand spectra. The fluorescence response over most of the survey area consisted mainly of relatively low confidence fluors (compared to the more reliable MkIII ALF survey data). Some of the regions of increased fluor density correspond to regions having generally higher F/R values, probably caused by changing water properties. These areas may not necessarily have increased levels of hydrocarbon leakage.

The Barrow/Dampier airborne laser fluorosensor (ALF) survey was flown in May 1994 using the ALF MkIII system. This system uses a 266nm laser wavelength, shorter than the 308nm used in the MkII system. The Raman peak wavelength is 293nm and the fluorescence region is 320nm to 580nm. Approximately 20,000km of data was acquired in a NW-SE direction with a line spacing of 1000m. The survey covers several oil and gas fields including Goodwyn gas and condensate field, North Rankin gas field, Cossack and Wanaea oil fields, Legendre oil field and the Wandoo heavy oil field. Several additional lines (10010 to 10140) were flown over part of the Goodwyn field and these were separated during the initial analysis. This avoided the closer line spacing affecting the fluor patterns on the regional mapping. The 14 Goodwyn lines contain 117,558 spectra. The data was re-interpreted using ALF_Explorer software, which showed that several low intensity fluor clusters could be identified on the Barrow/Dampier ALF survey. These clusters should be compared with geological interpretations to determine their cause. The wide 1km line spacing may be too wide to identify any higher intensity fluor clusters. Fluor spectra shapes are unusually consistent over this survey. This is reflected in the fluor peak wavelength map (Figure 11). The Goodwyn ALF survey with a 500m line spacing detected many more fluors than the regional survey, including many of higher intensity. The Goodwyn survey does not cover a wide enough area to show if the fluor clusters are associated with accumulations.

Legacy product - no abstract available

ACRES Update, Issue 21, July 2000 Terra Oberving the Earth New Product Catalogue Remote Sensing and emergency management

Offshore hydrocarbon reservoirs can experience oil and gas seepage through the seafloor and water column, resulting in tell-tale slicks on the sea surface. Detecting and identifying these intermittent and often remote slicks can contribute to directing exploration resources in both producing and frontier basins. Remote sensing, the acquisition of image data from sensors mounted on airborne or spaceborne platforms, is seen as a potential tool for detecting, mapping and identifying these seepage-derived slicks. Simply put, it offers a cost-effective means of scanning extensive and/or remote regions, on an ongoing basis.

ACRES Update, Issue 17, July 1998 New leap forward as ACRES offers JERS data

Airborne hyperspectral data covering about 2500 km2 were obtained from the Eastern Goldfields Superterrane (Yilgarn Craton, Western Australia), which is highly prospective for Archean Au as well as komatiite associated Fe-Ni sulphide mineralisation. In this project hyperspectral airborne data allowed not only the remote mapping of mafic and ultramafic rocks, which are among the main host rocks for Archean Au deposits in the study area, but also the remote mapping of hydrothermal alteration patterns and various geochemical signatures related to the structurally controlled Au mineralisation down to a 4.5 m pixel size. We can reconstruct fluid pathways and their intersections with steep physicochemical gradients, where Au deposition presumably took place, by combining hyperspectral remote sensing with hyperspectral drill core data in 3D mineral maps. White mica mineral maps as well as mineral maps based on the abundance and composition of MgOH and FeOH bearing silicates are the main products for a semi-quantitative assessment of the key alteration minerals in this project. In the southern Selwyn Range, Mount Isa Inlier, Queensland, hyperspectral mineral maps, such as "ferric oxide abundance", "white mica abundance" and "white mica composition", were integrated with geophysical datasets (total magnetic intensity, ternary radiometric imagery). The integration of the datasets enabled us to construct a comprehensive fluid flow model contributing to our understanding of iron-oxide Cu-Au deposits in this region, identifying the source, pathway and depositional sites, which are in good accordance with known deposits.

The Australian Geological Survey Organisation (AGSO) carried out a regional water column geochemical 'sniffer' program on the NW Australian Margin, from Dampier to the west of Darwin, over the period 21 September to 23 October 1998.. The overall objective of the survey was to acquire bottom water hydrocarbon data of the Northern Carnarvon Basin, offshore Canning Basin, Yampi Shelf and the Southern Bonaparte Basin, particularly in regard to detecting natural hydrocarbon seepage. A total of 4788 line km of sniffer data were acquired during the program, using the contract vessel TSMV Pacific Conquest. 160 survey lines were completed.Weak to moderate concentrations of methane and moderate to strong concentrations of ethane were detected in the waters surrounding the Wandoo B Platform, Northern Carnarvon Basin. Elsewhere in the northern Carnarvon, Skua, AC/P20, AC/P25-26, AC/P27 and AC/P23 survey areas, detected hydrocarbon seepage was close to background concentration indicating that seepage was either absent or of very low level.Moderate to strong methane and ethane concentrations were detected on parts of the Yampi Shelf. It is significant to note that there is a measure of repeatability of methane and ethane sampled between S176, recorded in 1996 and these data recorded in 1998. The levels measured, coincident with AGSO seismic lines S165, confirm hydrocarbon leakage where the regional seal thins onto the Kimberley Block basement (O'Brien et al., 1998a).