Why the ocean in Grenoble? #1- Coriolis Platform | Echo Science

At first glance, we don't think of the oceans when we talk about Grenoble. Waves, waves, currents, ports… In short, everything that can evoke the ocean seems very distant… However, for this national theme of the 2024 Science Festival, we were able to discover the actors in science and the scientific and technical culture linked to this great blue. You can find them in our short series “Why the ocean in Grenoble?”.

Coriolis platform

Coriolis platformLocated in the Geophysical and Industrial Flows Laboratory (Legi) It looks like a giant juicer. With a diameter of 13 meters, it is the world's largest rotating platform dedicated to fluid mechanics.

The first platform was built in 1960 and then rebuilt in Saint-Martin-d'Herre in 2014 with improved performance. Its main activity is the experimental modelling of geophysical flows, taking into account the rotation of the Earth, in the presence or absence of stratification or topography.

Understanding the Coriolis force…

The LEGI platform takes its name from the Coriolis force. Any element moving on the surface of a rotating system experiences a force perpendicular to its speed of motion: to the right in the Northern Hemisphere, to the left in the Southern Hemisphere. This is the Coriolis force. As the Earth rotates, the Coriolis force acts on ocean currents. The name is well chosen for a platform that rotates to model, for example, the movement of water masses in an Earth frame of reference.

During the Science Festival, schools and the general public will have the opportunity to do some experimental activities to visualize and understand this Coriolis force.

Privacy of forms

Well, the platform rotates to reproduce the rotation of the Earth but… it's more complicated than that! Two other parameters also have to be taken into account: the topography (morphology) of the seabed and also differences in water density (temperature and salinity).

By reproducing these factors, it is possible for them to reproduce a large number of natural phenomena, such as the rolling of hurricanes or the behavior of the mediums (food from the swirling waters that form near Gibraltar and move in the Atlantic Ocean over thousands of kilometers, contributing to the transfer of heat and nutrients) but also to understand the phenomena that govern the appearance of tsunamis. All these natural events are key phenomena in the life of the planet.

These are the advantages of making models, small-scale models of nature. And in the LEGI laboratories, they can reproduce on a case-by-case basis using resin models and conditioning the water used during the experiment. To the delight of the public who come… to the Coriolis Platform Open Days.

Reception of the public

As a cutting-edge European facility, the Coriolis Platform regularly welcomes researchers at both national and international levels. Since 2015, LEGI has opened its doors to the public during the Science Festival. Researchers and engineers also regularly welcome Coriolis visitors in organized groups (high school courses, inter-age universities, physics teachers’ conference, Hydralab conference, etc.).

During these visits, they invite you to enter the Coriolis tank and do demonstrations to learn in a fun and innovative way and feel, for example, the Coriolis force. The small educational platform, created by the laboratory, makes it possible to visualize certain phenomena, such as the formation of a hurricane.

So you might be the next visitor to Coriolis, during the 2024 Science Festival from October 4-14!

Article by Chloe Touati

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