Gravity applications enabled by quantum sensors. Perspectives for the FIQUgS project.

The measurement of gravity acceleration and of its variations are commonly used by geophysicists in many Earth sciences applications. It is quite well known that gravity at the surface of the Earth is influenced by the masses surrounding the instrument, so its measurement can be exploited to characterize subsurface mass density distribution and to investigate many phenomena related to the Earth lithosphere. Gravity measurements also contribute to the exploration of underground resources (mining, hydrology, oil & gas) as well as to civil engineering activities with the detection of voids and cavities. Quantum gravity sensors have already demonstrated interesting competitive advantages with respect to classical gravimeters since they can measure the field with a higher accuracy and they allow to perform absolute measurements. In the framework of FIQUgS project, funded by the European commission in 2022, a new generation of quantum gravity sensors (QGs) is under development to overcome the barriers limiting the first-generation sensors operational usage (e.g. the transportability and robustness not suitable for outdoor operations). Within the project, a new Absolute Quantum Gravimeter (AQGs) and a Differential Quantum Gravimeter (DQGs) are foreseen to allow not only on field absolute gravity measurements but also measures of the vertical derivative.

In the context of the FIQUgS project a wide review of potential use cases for quantum gravity sensors has been performed. Applications, which benefits from the advantages of the next generation QGs, have been identified, within different market sectors. Different scenarios have been considered and by means of specific synthetic simulations the capabilities of this technology have been assessed.

The potential applications for QGs investigated can be divided in two macro-sectors: the first one includes all the static applications that aim at retrieving the density distribution within a certain area to distinguish any kind of target (e.g. geological models for mining exploration, voids and cavities detection, archeological applications…). The second sector includes dynamic, or the so-called time variable applications which are instead focused on analyzing the temporal variability of potential field signals linked to mass changes (e.g. monitoring of CCS, hydrology variations etc.). For each of the identified scenarios a simulation has been set, which means to build a synthetic model of the study area and analyze its effect in terms of gravity supposing different hypothesis and background information.

The results of this analysis will be here presented showing potentialities of quantum sensors and advantages of this next generation of instruments for geophysics applications.