Development of new tools for in situ measurements and to identify precursors to submarine landslides

Penfeld penetrometer

In the frame of the ANR MODAL project (Task 2), Ifremer is in charge of the development of a new in situ instrument called “TIPS” (Temperature, Inclination and Pressure Sensors) to measure the evolution of pore pressures and deformation in the sediment with the aim of identifying landslide precursors prior to failure events.

This development relies on the experience gained in Ifremer in developing and deploying a piezometer (V3 model) that can be pushed in the sediment using the Penfeld penetrometer. Following a similar principle, two TIPS are planned to be deployed in 2020 off the Nice Airport. They will be made of coilable tubes assembled together to reach of total length of 50 m. Pore pressure and temperature will be measured at different levels where the tubes are assembled while inclination will be measured within the tubes at a minimum spacing of 30 cm. The instruments are planned to carry out continuous measurements over about a decade following their installation in sediment.

During the first 12 months of the project, studies have focused on answering the needs and constraints of functional specifications. This work is now synthesized in an approved technical specifications document. It is worth mentioning that during the preliminary project phase no major barrier to the development of the TIPS has been identified. Ongoing works focus on the selection, testing and qualification of inclination sensors in Ifremer.