Legacy product - no abstract available

Legacy product - no abstract available

Legacy product - no abstract available

Christmas Island lies about 1600 km north-north west of Australia's Northwest Cape and approximately 350 km south of Java in the northern part of the Wharton basin (IndianOcean). Recently Australia declared a 200 mile Fisheries Zone around the island andAGSO was asked to assess seabed morphology, sediment thickness and offshore mineralresources in this area. In February 1992 RAT "Rig Seismic" carried out a detailed survey ofthe region, providing relevant data for the required assessment. Eight seismic profiles wereacquired on this cruise, totalling about 2000 km, and almost twice as much bathymetricdata was recorded. In conjunction with seismic and bathymetic data collected by otherinstitutions, our data provides a good coverage of the area, which enabled us to compile anew bathymetric map and to produce the first sediment thickness map. Among the published bathymetric maps only three cover the Christmas Island area: 1)published by Udintsev (Geophysical Atlas of the Indian Ocean, 1975; 1:5,000 000), 2) byMammerickx et al. (1976, 1:5,000 000) and 3) 1:10,000 000 General BathymetricCompilation (GEBCO) map, published by the International Oceanographic Service (1982).All published bathymetric maps were compiled in the end of the 1970s and the beginningof the 1980s, and all of them were based on processing analog records of water depths andwere drafted manually. Moreover, most of the data for map compilation were collectedusing a sextant, and only a very limited using satellite navigation. The amount and quality of data collected by the end of the 1970s allowed the production ofthe fairly accurate 1:5,000 000 and 1:10,000 000 maps of the Indian Ocean listed above,however a lot of smaller features, such as individual seamounts, are missing on those maps.Insufficient data coverage led to broad extrapolation of bathymetric trends, sometimesderived purely from magnetic lineation pattern (Fig.1). To the east of Christmas Island thelack of information is particularly evident: all the maps differ in their interpretation of this area. New high quality data collected by "Rig Seismic", and digital water depths obtained fromthe USA National Geophysical Data Bank (NGDC), were used for compilation of a newrevised version of the bathymetric map on the Christmas Island area in a 1:1,000 000 scale.The new map (to be published in AGSO's Offshore Resources Map Series) contains a lotmore detail on the complex bathymetry of the area, and gives a more realistic picture ofseamount distribution and the structure of the Java Trench and Java's outer-arc ridge. Theamount of added information can be clearly deduced from comparison of Fig.1 and Fig.2.The time scale used in this report is that of McDougall (1974) and Fanoon et al. (1993).

The Christmas Island Geographic Information System (CIGIS) is a collection of spatial data, viewing and analysis tools dealing with Christmas Island. The data include orthophotography, topographic, mining, cultural and environmental features of the island. Compilation of data and its organisation into a GIS together with documentation was undertaken by the Australian Geological Survey Organisation (AGSO) at the request of the Territories Office, Department of Transport and Regional Services (DOTRS). The data are presented in both ESRI ArcView and ArcExplorer projects. The ArcView projects require a licensed copy of ArcView. ArcExplorer is a free viewer and is distributed with the Cocos GIS CD-ROM. Data are stored as ESRI shapefiles and therefore readily useable with most modern GIS applications. Data were received from a variety of custodians and in many cases had no accompanying documentation. Lack of documentation made it increasingly difficult for AGSO with interpretation, translation and documentation of data. AGSO has attempted to include metadata for all datasets to ANZLIC core metadata standards, but the value of this is limited by the poor initial documentation. In addition to limited documentation, many datasets had inconsistent spatial accuracy. The CocosGIS comprises four main CD-ROMs with additional CD-ROMs containing full-colour orthophotography. A hard-copy user guide is distributed with the main CD-ROM set.

This map has been created to update the old Crimes at Sea maps produced in 2000. These maps have been checked & approved by the Attorney Generals Office April 2013. There are 13 maps in the series plus the main map showing all of the Australian Territory. The AAT maps have not been released to the public as yet. Located in M:\Products\Australias Crimes Act Offshore Areas\products

Printed Orthophoto map.

This map shows the boundary of the security regulated port for the purpose of the Maritime Transport & Office Security Act 2003. 5 Sheets (Colour) May 2010 Not for sale or public distribution Contact Manager LOSAMBA project, PMD

Christmas Island is an Australian territory lying south of Java inthe Indian Ocean, at about 10°30'S and 105°40'E. It lies on oceanic crust of Late Cretaceous age, is moving north at 7cm/year, andis being raised as it climbs the bulge on the southern flank of the Java Trench. The island itself consists of Cainozoic volcanics and limestone, and has been extensively mined for Pliocene phosphate. It covers an area of 140 km2 , and rises 360 m above sea level. Australia has declared a 200 mile Fisheries Zone around the island, and the aim of this BMR investigation is to assess the seabed morphology, sediment thickness, and offshore mineral resources in a future Exclusive Economic Zone. This information will be of particular value to the Department of Foreign Affairs and Trade, when Australia negotiates a Christmas Island seabed boundary with Indonesia to the north. Present knowledge indicates that oceanic crust is generally at 5000-6000 m around Christmas Island, and that it is overlain by 100-300m of pelagic sediment which thickens northward toward the Java Trench. A number of volcanic ridges trend generally northeast or north-northeast, and are as shallow as 1200 m below sea level. Christmas Island itself sits on such a ridge. Shallow-water limestones and manganese oxide crusts have been dredged from the ridges. Deepseacoring programs show that pelagic foraminiferal ooze and marl give way to siliceous (diatom-radiolarian) ooze and red clay below 5000 in water depth. Volcanic ash from Indonesia is an additional component of the sediment. Reconnaissance sampling has shown that manganese nodules are quite common in the deep sea, and that they carry moderate grades of the valuable metals, copper (Cu), nickel (Ni) and cobalt (Co). In a fairly similar geological setting to the west, in the central Indian Ocean, India has pioneer investor status for a nodule mine site of 150,000 square kilometres. At this site the grade of Cu+Ni+Co is about 2.55%,and nodule abundance is 5-7.5% of wet nodules per square metre, figures which suggest that the site has long-term economic potential. The present project will commence with a 28-day geoscience cruise of R.V. "Rig Seismic" from 7 January to 4 February, 1992. The plan isto acquire about 2500 km of high-resolution reflection seismic and bathymetric data, to define seabed morphology and to allow regional mapping of sediment thickness and facies. The seismic data will beused as the basis of a sampling campaign to investigate sediment type, manganese nodule abundance and metal grade on the deepsea floor, and manganese crust thickness and metal grade on the volcanic ridges. The end result will be a comprehensive review of the geology and mineral resources of the Christmas Island offshore zone.

The Christmas Island Geographic Information System (CIGIS) is a collection of spatial data, viewing and analysis tools dealing with Christmas Island, Indian Ocean. The data include orthophotography, topographic, mining, cultural and environmental features of the island. This work is part of ongoing service to the Department of Transport and Regional Services.