Space Technology to Detect Threats to Sites on Earth Vancouver engineers for Amec, the UK engineering services firm, began working to test a down-to-earth use for Satellite Earth Observation technology with the European Space Agency (ESA). The tests will locate and evaluate potential land subsidence problems at seven sites around the globe. Land subsidence can cause significant structural damage to highways, dams, pipelines and buildings if not identified and dealt with early.Under an ESA-funded technology development contract, Amec is working with some of the world's largest resource and infrastructure development companies who must deal with land subsidence problems on projects throughout the world.Testing began in November at underground mine workings in northern Ontario for Placer Dome; a reclaimed mine waste rock dump in California for Kinross Gold; a railway in Germany for Deusche Bahn; tunnel construction in Germany for Walter Bau; a salt mine in Germany for Sudsalz; an open pit mine in South Africa for Rio Tinto; and a mine access road in Peru for Teck Cominco. The tunnel built by Walter Bau is a road tunnel built under the historical city of Dillenburg. The project is sensitive because tunnelling is located nearby an ancient castle. It is important that ground movement be monitored to ensure that the tunnel does not result in damage to the castle. The tunnel's length is 800 m, whereof 100 m in cut-and-cover, and the diameter is about 10 m. A 500 m rescue tunnel will also be built as well as an exhaust centre and exhaust tunnel to a chimney at the portal. The drill/blast method is used, with full round sealing due to high water levels. A inner concrete lining, about 40 cm thick, is poured. The overburden ranges from 9 to 40 m. The tunnel will cost €40 million.The project uses technology that involves images acquired from satellites. The satellites can detect changes in the ground surface with a vertical precision of a few millimetres. This information can find zones of ground settlement that could harm existing or future facilities.Amec is being assisted by subcontractor and strategic partner Atlantis Scientific, an earth observation provider, and Infoterra of the UK to provide high-resolution optical imaging services that can be used to help interpret the satellite data. Additionally, the Land Use Planning and Natural Risks Division of BRGM (French Geological Survey) will provide scientific review of the project. More from colin.russell@amec.com, project manager, or john.kageorge@amec.com, communications at Amec Vancouver office. Subscribe to E-News Weekly 31/2003. 50/04.