IMOS acoustic observatories
Three underwater acoustic observatories have been deployed on Australia’s continental shelf in the Indian, Southern and Pacific Oceans in 2009 as part the Integrated Marine Observing System (IMOS) of the National Collaborative Research Infrastructure Strategy program. The observatories are a new national research facility, which will provide long-term passive underwater acoustic observations for studying abundance and migration of marine mammals in Australian waters and for investigating other natural sources of noise in the ocean, such as earthquakes, underwater volcanoes and ice breaking processes in Antarctica.
Each observatory consists of four autonomous sea noise loggers deployed on the seafloor to form a triangular array of about 5 km sides with the fourth logger installed in the centre. The observatories can autonomously collect sea noise data over 8 to 12 months at useable frequencies up to 3 kHz, depending on the regime programmed for recording. After each cycle of autonomous recording, the observatories will be recovered for data retrieval and then redeployed for another recording cycle. It is planned to keep almost continuous data collection from the three observatories until at least 2013. Sea noise data from the IMOS acoustic observatories will be available for the scientific community worldwide.