Ocean Bottom Seismographs

Australia’s latest addition to the AuScope seismic monitoring instrumentation pool are ready for deployment. Manufactured by the earthquake sensor experts at Guralp Systems in the UK, these 20 OBS units will be dropped to the sea floor at depths of up to 6 kilometres. The pressures at these depths are extreme, so all of the sensitive electronic equipment is housed in titanium spheres and cylinders, with floatation provided by blocks of syntactic foam (as used in the deep ocean submarine piloted by Titantic director James Cameron). OBS units sink to the sea floor and can sit and record data for up to 12 months, and can be recovered on command by sending an acoustic signal to release their concrete ballast with the aid of carbon fibre leaf springs. Some truly amazing engineering and technology has gone into these systems, and will provide valuable data to Australian geoscientists for years to come.