Probing the deep Earth's interior by synergistic use of observations of the magnetic and gravity fields, and of the rotation of the Earth: GRACEFUL

Programme(s): H2020-EU.1.1. - EXCELLENT SCIENCE - European Research Council (ERC)
Topic(s): ERC-2019-SyG - ERC Synergy Grant
Call for proposal: ERC-2019-SyG
Funding Scheme: ERC-SyG - Synergy grant

Grant agreement ID: 855677

Project description
An algorithm to boost knowledge of the Earth’s core
What is inside the Earth? Our knowledge of the internal structure of our planet has increased significantly, but so much remains unknown. Currently the main methods of observing the Earth’s liquid core are indirect satellite and ground continuing observations. These methods, however, are mostly focused on and restricted to time dependent observations of the magnetic field, gravity field variations and Earth rotation changes. Moreover, they are usually incomplete as they address global integrated quantities. The EU-funded GRACEFUL project will reverse this lack of information. It plans to do this by developing cutting-edge methods to process these observational data together and employ up-to-date numerical models of the core flow that will help to acquire novel information on the Earth’s core.

Objective
To understand the processes involved in the deep interior of the Earth and explaining its evolution, in particular the dynamics of the Earth’s fluid iron-rich outer core, only indirect satellite and ground observations are available. They each provide invaluable information about the core flow but are incomplete on their own:
- The time dependent magnetic field, originating mainly within the core, can be used to infer the motions of the fluid at the top of the core on decadal and subdecadal time scales.
- The time dependent gravity field variations that reflect changes in the mass distribution within the Earth and at its surface occur on a broad range of time scales. Decadal and interannual variations include the signature of the flow inside the core, though they are largely dominated by surface contributions related to the global water cycle and climate-driven land ice loss.
- Earth rotation changes (or variations in the length of the day) also occur on these timescales, and are largely related to the core fluid motions through exchange of angular momentum between the core and the mantle.
The GRACEFUL project will go beyond the potential of individual satellite and ground observations and will combine the information about the core deduced from the gravity field, from the magnetic field and from the Earth rotation in synergy, in order to examine in unprecedented depth the dynamical processes occurring inside the core and at the core-mantle boundary.
We will develop cutting-edge algorithms to process observational data and use up-to-date numerical models of the core flow to infer its dynamics. This interdisciplinary approach will challenge our current understanding of the core dynamics and provide a step change in our understanding of the deep Earth’s interior.
The pioneering approach of GRACEFUL will provide an innovative template to obtain totally novel information about the dynamic processes inside the fluid core and core-mantle boundary of the Earth.