The objective of the WP3 “Instrumentation” is to organize the management of instruments acquired in the Equipex CRITEX (PIA2, 2012-2022) through an inventory of the acquired sensors, their current use and the identification of those that can be shared. The objective is also to reflect on the needs for innovative instrumentation to document the Critical Zone, and to share the know-how of the different OZCAR-RI’s communities, in particular on common themes (extreme climatic conditions, remote transmission, etc.). The WP3 also aims to converge towards harmonized protocols as well as set of variables.
From the Equipex CRITEX to the Equipex + Terra Forma : a structuring effect for instrumenting the Critical Zone
The Equipex CRITEX was funded under the Plan d’Investissement d’Avenir (PIA 2), for 10 years (2012 to 2022). Thanks to the €7 million investment range and the €2 million operating range obtained, the CRITEX programme has made it possible to develop new prototypes for monitoring groundwater, soil, air, and water, and to purchase shared instruments to bring the community up to standard and cross-reference observations that were not previously carried out jointly by the various scientific communities. CRITEX has also made it possible to deploy a high density of instruments on specific sites (“hot spots”) or to focus on “hot moments”, i.e. specific temporal events in some of the OZCAR RI observatories.
For further information on the completed Equipex CRITEX, you can visit the programme website : ouvrir
Deploying an innovative and all-field instrumentation
Instrumental and methodological developments are at the heart of WP3’s activities.
Thanks to the CRITEX programme, OZCAR RI has an incredible set of instruments at its disposal, providing the scientific community with cutting-edge equipment, particularly for the acquisition of in situ high-frequency geochemical data (Riverlab) and cross-linked geophysical data (gravimetry, seismic measurements, magnetic resonance, etc.). The management and deployment of CRITEX instruments at various observatories is carried out by two engineers whose work is partly dedicated to OZCAR RI: Sylvain Pasquet, an expert in geophysics, post-doctoral fellow at IR OZCAR from February 2018 to December 2022, and now CNRS research engineer at METIS, and Eliott Chatton, CNRS research engineer at Géosciences Rennes, a specialist in dissolved gases.
The inventory of Equipex CRITEX instruments is continuing, in order to provide the community with a complete list of equipment (PI, localisation, status, activity, future deployability).
Discover the “hidden” compartments of Critical Zone
Our knowledge of the deep structure of the Critical Zone, is indeed, rather limited, while its plays a main role in many key processes such as groundwater circulation and storage, water-exchange between soil and vegetation or soil formation and sediment production. Sylvain Pasquet’s expertise in geophysical imagery has been used to “highlight” these “hidden” compartments of the Critical Zone using geophysical methods available through CRITEX.
Thanks to the S. Pasquet’s post-doctoral work, numerous acquisitions of geophysical data (seismic, electrical resistivity) have taken place since 2019 on various experimental sites of the OZCAR RI. The corresponding data acquired is available on the hydrogeophysical database managed at Géosciences Rennes (https://hplus.ore.fr/).
Consideration has also been given to implementing a similar strategy for monitoring and characterising the OZCAR RI’s sites, this time using dissolved gases. It is being led by Eliot Chatton, research engineer at Géosciences Rennes and it will focus on 4 areas: (i) characterisation of dissolved gas concentrations at OZCAR IR sites, (ii) support for scientific projects led by site managers, (iii) monitoring of O2 and CO2 flows in and from the deep critical zone (cross-cutting theme), and (iv) development of dissolved gas measurements in new contexts (boreholes, rivers, hyporheic zones, peat bogs, hydrothermal springs). Pending implementation of this strategy, preliminary measurement campaigns have been launched at various OZCAR RI sites (OTHU-BV Yzeron, OHMCV and OBSERA).
Instrumental and methodological developments are also being addressed as part of the EQUIPEX+ Terra Forma project, and this has led to the involvement of WP3 players in this project.
Setting up an instrumentation and measurement network
In 2022, an instrumentation and measurement network was set up within OZCAR RI: “OZCAR-CRITech” taking the form of a RENATER mailing list (email@example.com) with almost 80 subscribers to date (summer 2023). This list is aimed at all practitioners and users of critical zone instrumentation, enabling them to discuss the technical issues they encounter. The objectives of this network are therefore dedicated to (i) sharing technical know-how, (ii) converging towards harmonised protocols and sets of variables (systematic approaches, common strategies) and (iii) stimulating the development of innovative instrumentation for the Critical Zone.
Improve instrumentation’s visibility: sessions, workshops and training courses
In order to improve the visibility of the instrumentation, presentations are planned at various scientific events linked to the subject of the Critical Zone: conferences such as the 2nd TERENO OZCAR conference in September 2023 or the OZCAR summer schools (presentation of the operation of the geophysical instruments and the mobile laboratory resulting from the EQUIPEX CRITEX).
A series of workshops on passive geophysics have also been organised, with the aim of highlighting instrumentation in the Critical Zone. The 1st workshop dedicated to passive geophysical methods was held in a hybrid format in Montpellier in 2022 and brought together nearly 30 participants. The 2nd passive geophysics workshop will be held in Paris in autumn 2023.
People involved in WP3 are also collaborating with those in the Equipex + Terra Forma project, who are involved in instrumental and methodological developments relating to low-cost sensors, and are therefore taking part in events organised by the project Terra Forma.
The organisation of training courses on the park’s instruments and free data processing tools is also on the agenda.
You can find the latest developments in WP3 and an assessment of the Equipex CRITEX in the newsletter OZCAR 2023. You will also find a report on the Equipex + Terra Forma in the newsletter OZCAR 2022.