This extended abstract describes the 1:1 million scale Surface Geology of Northern Territory digital dataset and advances in digital data delivery via WMS/WFS services and the GeoSciML geological data model.

GSA Abstracts

This was the fifth in the series of successful Forums on geoscience information management that have been held in Canberra since 1993. With the growing use of the Internet for access and delivery of data and services, it was timely to address issues relating to the provision of geoscience online. 2001 will see the implementation of the Federal Government's online policy. AGSO along with state geological agencies will present their online data delivery initiatives. The Forum included a range of speakers dealing with the online delivery of spatial geoscience data, from geoscience-related vendors through to the latest developers in web technology. The geoscience sector is on the cusp of taking full advantage of the potential of online delivery. Over the past 5 years most government agencies have been improving their data management practices and cleaning up their datasets, leading to a situation where the "backend" is in good shape. Some have begun to implement online delivery and eCommerce systems (GIS, image processing and database access) but uptake is uneven across the sector and such systems generally only deliver the lower volume, less commercially sensitive datasets. In the private sector we have begun to see the emergence of commercial data management consultants who are providing web based access to their clients, and, within the larger companies, some sophisticated intrAnet solutions have been put in place. A small number of players are looking at providing online value-added services for clients like share market investors (mining/petroleum shares). This Forum provided the opportunity to find out the latest trends and developments in the exciting and growing area of internet and web technologies for the delivery of online information.

Scientific data are being generated at an ever increasing rate. Existing volumes of data can no longer be effectively processed by humans, and efficient and timely processing by computers requires development of standardised machine readable formats and interfaces. Although there is also a growing need to share data, information and services across multiple disciplines, many standards currently being developed tend to be discipline specific. To enable cross-disciplinary research a more modular approach to standards development is required so that common components (e.g., location, units of measure, geometric shape, instrument type, etc) can be identified and standardised across all disciplines. Already international standards bodies such as ISO and OGC (Open Geospatial Consortium) are well advanced in developing technical standards that are applicable for interchange of some of these common components such as GML (Geography Markup Language), Observations and Measurements Encoding Standard, SensorML, Spatial Coordinate Systems, Metadata Standards, etc. However the path for developing the remaining discipline specific and discipline independent standards is less coordinated. There is a clear lack of infrastructure and governance not only for the development of the required standards but also for storage, maintenance and extension of these standards over time. There is also no formal mechanism to harmonise decisions made by the various scientific disciplines to avoid unwanted overlap. The National Committee for Data in Science (NCDS) was established in 2008 by the Australian Academy of Science to provide an interdisciplinary focus for scientifc data management. In 2008 an informal request from the NCDS was put to the international Committee on Data for Science and Technology (CODATA) to consider taking on a new coordination role on issues related to the development and governance of standards required for the discovery of, and access to digital scientific data.

Introduction Geoscience data are being generated at exponentially increasing volumes, and it is no longer feasible to develop centralized warehouses from which data are accessed. Efficient access to such data online in real time from distributed sources is rapidly becoming one of the major challenges in building cyberinfrastructures for the Earth Sciences. EXtensible Markup Language (XML) and web-based data delivery is a proven technology which allows access to standardized data on the fly via the internet. GeoSciML (GeoScience Markup Language) is a geoscience specific, XML-based, GML (Geography Markup Language) application that supports interchange of geoscience information. It has been built from various existing geoscience data model sources, particularly the North American Data Model (NADM) and XMML (eXtensible Mining Markup Language). It is being developed through the Interoperability Working Group of the Commission for the Management and Application of Geoscience Information (CGI), which is a commission of the International Union of Geological Sciences (IUGS). The Working Group is (currently) comprised of geology and information technology specialists from agencies in North America, Europe, Australia and Asia. The GeoSciML Testbed In 2006, representatives from geological surveys in USA, Canada, UK, France, Sweden and Australia came together to develop a testbed that would utilize GeoSciML to access globally distributed geoscience map data (Duffy et al, 2006). Data was served from seven sites in six countries with several different WMS/WFS (Web Feature Service/Web Map Service) software solutions employed. Geological surveys in Canada, USA and Sweden used an ESRI ArcIMS platform (and in one case a MapServer platform) with a Cocoon wrapper to handle queries and transformations of XML documents. The UK and Australian geological surveys employed the open source GeoServer software to serve data from ArcSDE and Oracle sources. The French geological survey implemented a system using an Ionic RedSpider server for WMS and client, and a custom development to implement a WFS. Web clients were constructed in Vancouver, Canada using Phoenix, and later in Canberra, Australia using Moximedia IMF software to test various use case for the WMS/WFS services. Generic web clients, such as Carbon Tools Gaia 2 were also used to test some use cases. In addition to geologic map data, the testbed also demonstrated the capacity to share borehole data as GeoSciML. Two WFS (French and British) provided borehole data to a client able to display the borehole logs.

No abstract available

The current Australian gravity datum, Isogal84, is defined by the Australian Fundamental Gravity Network (AFGN). The AFGN consists of more than 950 stations at over 250 locations throughout Australia with the first stations in the network being established in the early 1950's. Prior to Isogal84, the datum was based on relative ties to overseas sites. The Isogal84 datum is based on 5 absolute gravity sites within Australia that were established in 1979 using a Soviet absolute gravimeter. Absolute gravity measurements conducted at 60 AFGN sites by Geoscience Australia using a portable absolute gravimeter have shown that the Isogal84 datum is 78 microgals (1 microgal = 1x10-8 m/s2) higher than the absolute measurements. A new gravity datum, the Australian Absolute Gravity Datum 2007 (AAGD07), has been defined based on these absolute gravity measurements and the AFGN and the Australian National Gravity Database (ANGD) have been adjusted to this new datum. Concurrent with implementing AAGD07, the formulae used for reducing gravity data in the ANGD have been reviewed and updated. These changes include using the 1980 International Gravity Formula, ellipsoidal heights, and a spherical cap bouguer correction that accounts for the Earth's curvature. These new formulae provide more accurate anomalies, particularly in longer wavelengths which will be beneficial to regional studies.

Many of the methods commonly used to calculate gravity anomalies have been around since the beginning of gravity surveying when calculations were done by hand and local horizontal and vertical datums were used. These days computing power is not a concern and most surveys are carried out using GPS technology with global datums. Geoscience Australia is reviewing the methods used to calculate gravity anomalies in the Australian National Gravity Database and is proposing changes such as the use of the GRS80 reference ellipsoid for calculating normal gravity and also as the height datum for anomaly calculations.

The Australian Fundamental Gravity Network defines the datum, Isogal84, for gravity surveys conducted in Australia and the surrounding oceans. It consists of over 900 gravity stations at over 250 locations. Geoscience Australia has conducted measurements with a portable absolute gravity meter at a number of these stations in order to improve the accuracy of this network and to provide a consistent framework for gravity surveyors. These absolute gravity measurements show that Isogal84 is 75 microgals (1 microgal = 1x10-8 m/s2) higher than the absolute datum and that the accuracy of the stations within the network is approximately 30 microgals.

This documentation manual for the Mount Isa dataset provides description of AGSOs mineral deposit database (OZMIN) - it's structure, the main data and authority tables used by OZMIN, database table definitions, details on the Microsoft Access version of the database and a listing of those deposits in the Mount Isa dataset