In 1996, NOAA’s PMEL laboratory developed autonomous moored hydrophones to augment fixed arrays likes those of SOSUS. These hydrophones are deployed from the deck of a ship and are weighted so that the hydrophone itself floats in the deep sound channel. These instruments are usually deployed in a array so that the location of a sound source (such as an earthquake) can be located. These hydrophones are capable of collecting data for 1 year. The instruments are then recovered via a ship, the data are retrieved, and the hydrophones are redeployed. Image courtesy of Sounds in the Sea 2001, NOAA/OER.
