Exploring for the Future (EFTF) is a four-year geoscience data and information collection programme that aims to better understand on a regional scale the potential mineral, energy and groundwater resources concealed under cover in northern Australia and parts of South Australia. This factsheet explains one of the activities being undertaken to collect this data and information.

Exploring for the Future (EFTF) is a four-year geoscience data and information collection programme that aims to better understand on a regional scale the potential mineral, energy and groundwater resources concealed under cover in northern Australia and parts of South Australia. This factsheet explains one of the activities being undertaken to collect this data and information.

This forum showcased the range of pre-competitive geoscience projects currently underway by Geoscience Australia and its collaborative partners under the UNCOVER themes with an emphasis on new projects arising out of the Australian Government’s four year $100M Exploring for the Future program which commenced in late 2016. The themes covered are: Cover and what lies beneath, character and thickness; 3D architecture, mapping the framework for mineral systems; 4D geodynamics and mineral systems of Australia; and, Mineral system footprints and toolkits for explorers

In the present, the GNSS body-fixed reference frame definition is followed according to the International GNSS Service (IGS) conventions [3] which are based on the spacecraft body frame of the GPS Block II/IIA satellites. This definition is also compatible with the GPS Block IIF satellites while in the case of the GPS Block IIR the spacecraft frame is designed with a reverse direction (away from the sun) in the X axis of the body-fixed frame. The situation is similar to the GPS IIA/IIF for the BDS satellites where +X axis points towards the Sun, +Z axis points to the SV’s radius vector towards the Earth’s centre in the antenna boresight direction, and the +Y axis completes the right handed system while it coincides with the rotation axis of the solar panels. The yaw angle is the critical parameter which defines the GNSS attitude. Contrary to GPS and GLONASS, BeiDou Inclined Geosynchronous Orbit (IGSO) and Mean Earth Orbit (MEO) satellites do not experience noon-turn and midnight-turn manoeuvres [6], with the exception of the newly launched IGSO6 or C13, formerly C15 (F. Dilssner and P. Steigenberger personal communication).

The data covers an area of approximately 8500 sq km in the Darling river catchment area, located between Bourke, NSW and Wilcannia, NSW. A set of seamless products were produced including hydro-flattened bare earth DEMs, DSMs, Canopy Height Models (CHM) and Foliage Cover Models (FCM). The outputs of the project are compliant with National ICSM LiDAR Product Specifications and the NEDF.

Large tsunami occur infrequently but can be extremely destructive to human life and the built environment. Management of these risks requires an understanding of the possible sizes of future tsunami, and the probability that they will occur over some time interval of interest. Herein we present a globally extensive probabilistic assessment of tsunami runup hazards, considering only earthquake sources as these have been responsible for about 80% of destructive tsunami globally. The global scale of the analysis prevents us from exploiting detailed site specific data (e.g. high-resolution elevation data, tsunami observations), and because of this we do not suggest the analysis is appropriate for local decision making. However, consistent global analyses are useful to inform international disaster risk reduction initiatives, and can also serve as a reference and potential source of boundary conditions for regional and local tsunami hazard assessments. A global synthetic catalogue of 17000 tsunamigenic earthquake events is developed with magnitudes ranging from 7.5 to 9.6. The geometry of the earthquake sources accounts for the detailed three-dimensional shape of subduction interfaces, when the latter is well constrained. The rate of earthquake events is modelled such that on each earthquake source zone, the earthquakes follow a Gutenberg-Richter magnitude-frequency distribution, and the time-integrated earthquake slip balances the seismic moment release rate inferred from the convergence of neighbouring tectonic plates. Tsunami propagation from each earthquake is modelled globally, and runup height is estimated roughly by combining the global model with heuristic treatments of nearshore tsunami amplification. We evaluate the accuracy of this approach by comparing runup observations from four globally significant historical tsunami with model scenarios having the same earthquake magnitude and location (i.e. without event-specific calibration). Around 50% of runup observations are within a factor of two of the model predictions. The dominant source of uncertainty in the modelled runup seems related to limitations in the earthquake source representation, with limitations due to the global runup methodology being a significant but secondary issue. These uncertainties are modelled statistically, and integrated into the hazard computations. In most locations, the modelled tsunami runup exceedance rate is sensitive to assumptions about the maximum possible earthquake magnitude on nearby earthquake source zones, and the fraction of plate convergence accommodated by non-seismic processes. We model the uncertainties of these (typically) poorly constrained processes using a logic-tree. For any site and chosen exceedance rate, this allows the mean runup (integrated over all logic tree branches) to be estimated, and associated runup confidence intervals to be derived. As well as highlighting the uncertainties in tsunami hazard, the analysis suggests relatively high hazard around most of the Pacific Rim, especially on the east coast of Japan and the west coast of South America, and relatively low hazard around most of the Atlantic outside of the Caribbean. Runup hazards on the east and west coast of Australia are relatively poorly constrained, because there are large uncertainties in the maximum magnitude earthquake which could occur on key source zones in the eastern Indian Ocean and western Pacific.

Cycle slip detection and repair are essential quality control steps in recovering the integer ambiguities when loss of tracking signals in GNSS precise positioning occurs. In this contribution, we present an improvement to the previous algorithm for reliable real-time cycle slip detection and repair of the Australian Analysis Centre Software (ACS) Pre-processing and Data Editing (PDE) function. First, the traditionally used algorithm based on the quality control theory is used to detect and repair the cycle slips. Then if the cycle slips are detected but not reliably repaired, the information of subsequent epochs are used together to strengthen the model and achieve a higher cycle slip repair success-rate. With such an enhancement, the model becomes more robust to accommodate the measurement noise and the ionosphere disturbance.

This report is the culmination of the Gippsland Marine Environmental Monitoring (GMEM) project. The GMEM was developed in response to stakeholder concerns from the fisheries industry about a Geoscience Australia seismic survey in the Gippsland Basin (GA352 in April 2015), in addition to a broader need to acquire baseline data to be used to quantify impacts of seismic operations on marine organisms. The GMEM involves six components: 1) Theoretical sound modelling, 2) Sound monitoring and field-based modelling, 3) Scallop assessment using an Automated Underwater Vehicle (AUV), 4) Scallop assessment using dredging 5) Fish avoidance behaviour using acoustic tagging and monitoring, and 6) Analysis of fisheries catch data. The results and interpretations of these components are detailed in this final report.

The Antarctic field notebooks contain the geological observations recorded by Bureau of Mineral Resources geologists during their trips to Antarctica between 1948 – 1980s. Files include a scanned copy of the original handwritten field notebook, transcription of the notebook’s contents transcribed by volunteers and validated by an experienced geologist, and a csv file of the transcription with Text Encoding Initiative (TEI) tags. The original Antarctic field notebooks are held at the N.H. (Doc) Fisher Geoscience Library at Geoscience Australia, Canberra.

Zip file containing all ModelVision files (created with ModelVision version 14.00.05) used in the GA Record: 'An integrative approach to investigating crustal architecture and cover thickness in the Southern Thomson region: Modelling new geophysical data'. All ModelVision files have the extension .ses and are named as per their location in the GA record described above. The zip file also contains an information (readme) file.