Measuring waves in the deep-sea

22 November 2017  – Geophysicists of  NIOZ Royal Netherlands institute for sea research and members of the KM3NeT Collaboration, have successfully anchored a unique 3D array with 550 high-resolution temperature sensors at the KM3NeT-Fr site, about 40 km offshore Toulon.  The device was anchored using the Ifremer/Genavir ship l’Atalante.

The temperature sensors are mounted on a structure of five parallel lines with a height of 100 m, 4 m apart. It is transported in a folded form and the arms of the structure and the folded lines with temperature sensors are unfolded overboard prior to deployment.

With  this device geophysicists in KM3NeT will study the motion of the Mediterranean Sea at a depth of about 2500 m. The deep sea is constantly in motion and waves develop supported by stable water layers. These internal waves in the deep sea are much slower than the waves at the surface, but are much higher: 10 m up to more than 100 m.  With the NIOZ device the turbulence and wave breaking in the deep sea can be measured with high precision.







See for an earlier deployment of the 3D sensor device the video below. First it shows the deployment of the top of the line with a.o. orange buoys. This is followed by a fascinating interplay of people pulling strings at the right time to unfold the structure. Once the structure is unfolded it is connected to the top  of the string before descending to the seabed.