From 1 - 10 / 286
  • Geoscience Australia is providing extensive advice, expertise and support to the Australian Transport Safety Bureau (ATSB). The ATSB is leading a seabed mapping and underwater search for missing Malaysia Airlines flight 370 in the southern Indian Ocean. Bathymetry is the study and mapping of the sea floor. It involves obtaining measurements of the depth of the ocean and is equivalent to mapping on land. Before the underwater search for MH370 could begin, it was necessary to accurately map the sea floor to ensure that the search is undertaken safely and effectively. Bathymetry survey vessels spent months at sea, scanning the sea floor with multibeam sonar to gather detailed, high-resolution data. The data has revealed many seabed features for the first time. This computer-animated 'flythrough' shows a visualisation of some of the sea floor terrain in the search area.

  • Gravity data measures small changes in gravity due to changes in the density of rocks beneath the Earth's surface. The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. This Southern_McArthur_Basin_Gravity_p201381_CSCBA267GUVD_geodetic.nc grid is a first vertical derivative of the Bouguer anomaly grid for the Southern McArthur Basin Gravity Surey 2013 survey. This gravity survey was acquired under the project No. 201381 for the geological survey of NT. The grid has a cell size of 0.00734852 degrees (approximately 800m). A total of 6278 gravity stations were acquired to produce the original grid. A Fast Fourier Transform (FFT) process was applied to the original grid to calculate the first vertical derivative grid.

  • Gravity data measure small changes in gravity due to changes in the density of rocks beneath the Earth's surface. The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. This Southern_McArthur_Basin_Gravity_p201381_CSCBA267GU_geodetic.nc grid is a complete spherical cap Bouguer anomaly grid for the Southern McArthur Basin Gravity Surey 2013 survey. This gravity survey was acquired under the project No. 201381 for the geological survey of NT. The grid has a cell size of 0.00734852 degrees (approximately 800m). A total of 6278 gravity stations were acquired to produce this grid.

  • Gravity data measures small changes in gravity due to changes in the density of rocks beneath the Earth's surface. The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. This Southern_Thomson_Gravity_Traverses_P201401_SCBA267GU_FILT.nc grid is a first vertical derivative of the Bouguer anomaly grid for the Southern Thomson Gravity Traverses survey. This LANDsurvey was acquired under the project No. 201401 for the geological survey of NSW, QLD. The grid has a cell size of 0.00095966 degrees (approximately 100m). A total of 3659 gravity stations were acquired to produce the original grid. The Spherical Cap/complete Spherical cap/Bouguer gravity grid was filtered using an algorithm from the INTREPID Geophysics software package to calculate this grid.

  • Gravity data measure small changes in gravity due to changes in the density of rocks beneath the Earth's surface. The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. This Gippsland_Basin_Gravity_P201430_SCBA267GU.nc grid is a complete Bouguer anomaly grid for the Gippsland Basin Gravity survey. This gravity survey was acquired under the project No. 201430 for the geological survey of VIC. The grid has a cell size of 0.00500777 degrees (approximately 500m). A total of 1213 gravity stations were acquired to produce this grid.

  • Gravity data measures small changes in gravity due to changes in the density of rocks beneath the Earth's surface. The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. This Sir_Samuel_Throssell_Gravity_Survey_P201460_CSCBA267_1VD.nc grid is a first vertical derivative of the Bouguer anomaly grid for the Sir Samuel Throssell Gravity survey. This gravity survey was acquired under the project No. 201460 for the geological survey of WA. The grid has a cell size of 0.00476548 degrees (approximately 500m). A total of 11663 gravity stations were acquired to produce the original grid. A Fast Fourier Transform (FFT) process was applied to the original grid to calculate the first vertical derivative grid.

  • Gravity data measures small changes in gravity due to changes in the density of rocks beneath the Earth's surface. The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. This Goldfields_Gravity_Survey_P201362_CSCBA267GUVD.nc grid is a first vertical derivative of the Bouguer anomaly grid for the Goldfields Gravity Survey 2013 survey. This gravity survey was acquired under the project No. 201362 for the geological survey of WA. The grid has a cell size of 0.00481677 degrees (approximately 500m). A total of 8119 gravity stations were acquired to produce the original grid. A Fast Fourier Transform (FFT) process was applied to the original grid to calculate the first vertical derivative grid.

  • Tsunami hazard maps are generated for the Mentawai Islands, West Sumatra, Indonesia, to support evacuation and disaster response planning. A random heterogeneous slip generator is used to forward model a suite of earthquake rupture scenarios on the Mentawai Segment of the Sunda Subduction Zone. A total of 1000 rupture models that fit constraints provided by coral and geodetic records of coseismic vertical deformation from great earthquakes in 1797, 1833 and 2007 are used to model inundation and define a maximum inundation zone that envelopes all of these scenarios. Results are compared with single scenario hazard assessments developed by experts and agreed through scientific consensus building processes to assess the additional value of modelling a suite of scenarios to obtain a more robust estimate of potential inundated areas by incorporating uncertainty in the earthquake source. The model presented here, like all tsunami hazard assessments, is based on assumptions about the characteristics of future events based on past events, however by sampling a range of plausible outcomes we gain a more robust estimate of which areas may be inundated during a tsunami within the bounds of our assumptions.

  • This poster shows the locations of large earthquakes occurring in Australia in the last 50 years. Also included are images from damaging earthquakes as well as the summary of large earthquake occurrences in Australia. Please note: The size of some the historical earthquakes referred to within this product may have been revised, for more information please follow the link at right to "Revisions to Australia's historical earthquakes."

  • This resource contains bathymetry and backscatter data for the Oceanic Shoals Commonwealth Marine Reserve (CMR) in the Timor Sea collected by Geoscience Australia during September and October 2012 on RV Solander (survey GA0339/SOL5650). The survey used a Kongsberg EM3002 300 kHz multibeam sonar system mounted in single head configuration to map four areas, covering a combined area of 507 square kilometres. Data are gridded to 2 m spatial resolution. The Oceanic Shoals Commonwealth Marine Reserve survey was undertaken as an activity within the Australian Government's National Environmental Research Program Marine Biodiversity Hub and was the key component of Research Theme 4 - Regional Biodiversity Discovery to Support Marine Bioregional Plans. Hub partners involved in the survey included the Australian Institute of Marine Science, Geoscience Australia, the University of Western Australia, Museum Victoria and the Museum and Art Gallery of the Northern Territory. Data acquired during the survey included: multibeam sonar bathymetry and acoustic backscatter; sub-bottom acoustic profiles; physical samples of seabed sediments, infauna and epibenthic biota; towed underwater video and still camera observations of seabed habitats; baited video observations of demersal and pelagic fish, and; oceanographic measurements of the water column from CTD (conductivity, temperature, depth) casts and from deployment of sea surface drifters. Further information on the survey is available in the post-survey report published as Geoscience Australia Record 2013/38 (Nichol et al. 2013).<p><p>This dataset is not to be used for navigational purposes.