Significance of the research project
Our understanding of how planets form and how life develops and is sustained over millenia, is based on models and hypothesis, and while we have had advances in understanding, the picture is far from complete. This is partly because the integration of existing knowledge across disciplines is preliminary at best.
This research project is relevant to several key questions, examples of which are the nature of the Earth’s magnetic field and how the interior of the Earth controls changes at the surface. Both are crucial: if the Earth’s magnetic field weakens, do we know enough about the deep Earth to predict future magnetic field strength, and thus the preservation of life? How is the energy in the interior of the Earth harnessed to bring to the near sub-surface potentially valuable mineral resources in geologic time? How are deformation processes at the Earth’s surface which interacts with human habitats, controlled by process within the deep Earth?
Everything we are expected to learn and integrate from this project will elucidate our fundamental knowledge about how the Earth works on multiple spatio-temporal scales and can be shared with others.
Background
Today, humans can access about 1% of the Earth’s volume. Information concerning the remaining 99%, and especially the mantle and core can be obtained only through geophysical surveys, or modelled through experiments in geochemistry, rock physics, and geodynamics. Earth Science subdisciplines that focus on the interior of the Earth include geodynamics, magnetohydrodynamics, and thermodynamics, to name a few. But in order to understand the complex processes and structure of the Earth’s interior, these disciplines must be integrated.
As an example of the linked processes within the Earth, the magnetic field is governed by the heat stored during the accretion, the convection processes in the core, the geochemical distribution of minerals and the magnetically-susceptible materials in the crust. Thus the geodynamo is driven by the physical, thermal and chemical processes in the core and mantle. Various phenomena alter the convection patterns in the mantle in non-linear ways, for example, the heterogeneous distribution of heat and geochemical species, as well as forces which act at changing spatio-temporal scales, including Earth rotation, Earth tides caused by luni-solar gravitation or the tilt of the Earth with respect to the ecliptic. The dynamic processes in the interior of the Earth are governed by many parameters and most importantly, they act on different spatio-temporal scales. Predictions into the future of the Earth’s magnetic field are only possible if all driving mechanisms are elucidated, and sampled at the appropriate scales.
Objectives
The proposed project will not only attempt to improve our knowledge for the specific problems mentioned above, but rather will address the dynamics and evolution of the Earth through an integrated and scale-focused approach. The following questions may be pertinent:
- Do we sample those spatial scales properly, e.g. are convection cells in the mantle realistic in scale? Do we sample the temporal scales correctly, e.g. how long does it take to recycle a subducted plate?
- What spatial and temporal scales can we identify from available observations and modelling experiments for Earth processes?
- What are the scaling limitations of each of those processes/observations, e.g. aliasing, under-sampling?
- What are the relationships between the scales of the distributions of Earth parameters and driving mechanisms?
- Can these relationships shed light on the evolution of plate tectonics and life on Earth?
- Can the scale approach be applied to other planets/moons in the solar system? What are differences that might impede this approach?
- What are the implications of this knowledge for the Moon and Mars?
- This list of questions is just an example of the many research opportunities provided in this research endeavour