The NEWTON-g Gravity Imager: Toward New Paradigms for Terrain Gravimetry

Abstract

Knowledge of the spatio-temporal changes in the characteristics and distribution of subsurface fluids is key to properly addressing important societal issues, including: sustainable management of energy resources (e.g., hydrocarbons and geothermal energy), management of water resources, and assessment of hazard (e.g., volcanic eruptions). Gravimetry is highly attractive because it can detect changes in subsurface mass, thus providing a window into processes that involve deep fluids. However, high cost and operating features associated with current instrumentation seriously limits the practical field use of this geophysical method. The NEWTON-g project proposes a radical change of paradigm for gravimetry through the development of a fieldcompatible measuring system (the gravity imager), able to real-time monitor the evolution of the subsurface mass changes. This system includes an array of lowcosts microelectromechanical systems-based relative gravimeters, anchored on an absolute quantum gravimeter. It will provide imaging of gravity changes, associated with variations in subsurface fluid properties, with unparalleled spatio-temporal resolution. During the final ∼2 years of NEWTON-g, the gravity imager will be field tested in the summit of Mt. Etna volcano (Italy), where frequent gravity fluctuations, easy access to the active structures and the presence of a multiparameter monitoring system (including traditional gravimeters) ensure an excellent natural laboratory for testing the new tools. Insights from the gravity imager will be used to i) improve our knowledge of the causeeffect relationships between volcanic processes and gravity changes observable at the surface and ii) develop strategies to best incorporate the gravity data into hazards assessments and mitigation plans. A successful implementation of NEWTON-g will open new doors for geophysical exploration.

A Nineteen Day Earth Tide Measurement with a MEMS Gravimeter

“…to a bias instability value of 8.18µGal. A network of these sensors is currently being constructed for deployment on Mount Etna as part of the NEWTON-g collaboration 20 , to create the first multi-pixel gravity imager.…”

“…With this application in mind, the authors have joined a consortium (NEWTON-g) to develop a gravimeter network on Mt. Etna comprising tens of MEMS gravimeter 'pixels' 20 , and a MuQuans Absolute Quantum Gravimeter 21 .…”

Quantum technologies for climate change: Preliminary assessment

“…Quantum sensors also offer the potential to improve climate risk scenarios by providing new or more accurate climate information on important indicators such as flooding and forest fire prediction. Quantum gravimeters are already being studied for use in volcano hazard assessments and mitigation plans [94].…”

Performance Assessment of Geophysical Instrumentation Through the Automated Analysis of Power Spectral Density Estimates

“…At present, the NSAN does not employ gravimeters for geophysical monitoring in its operational infrastructure, but acknowledges the potential for, for example, volcano monitoring in the Caribbean Netherlands, similar to what is being explored in the NEWTON‐g project (Carbone et al., 2020; Ménoret et al., 2018; Middlemiss et al., 2016), or for hydrothermal monitoring purposes (Sugihara & Ishido, 2008).…”