Have you ever wondered what the underwater world actually sounds like? Down below the waves, humans rarely get a chance to really ‘hear’ the ocean, saved for the lucky ones who can SCUBA dive for a brief amount of time. However, even they can only hear a tiny fraction of the subsea orchestra that reverberates around the world’s oceans. Many of these sounds are inaudible to human ears, however using passive acoustic monitoring (PAM) equipment, we are able to detect and analyse these transmissions. For example, in the video below we break down all the noises detected in a short underwater recording using spectrograms displayed in sonic visualiser.

It is encouraging to see marine science & offshore projects  continue to go ahead in these challenging times. This month RS Aqua have supplied Orca passive acoustic systems to multiple underwater noise projects in Europe. A titanium capped Orca will be used  at depths up to 2500 m for a project planned by the National Oceanography Centre in Southampton (NOC).

The project revolves around a seismic drilling operation on the mid-Atlantic ridge, where initially the Orca will monitor noise levels to get an idea of the frequency of the drill bit during operation. 1 year after the seismic drill study, NOC plans to run a cabled hydrophone from the recorder down into the hole, in order to measure the physical properties of the seafloor deposits. By using the interaction of the substrates with underwater acoustics, they hope to be able to determine the composition of the deposits. They also hope to be able to use their Orca recorder for future marine mammal detection and any future seismic surveys.

For more information on Orca, Click here