Details of Award
NERC Reference : NE/C519662/1
The structure and anisotropy of the Earth's inner core.
Grant Award
- Principal Investigator:
- Professor L Vocadlo, University College London, Earth Sciences
- Co-Investigator:
- Professor D Price, University College London, Office of Vice Provost Research
- Co-Investigator:
- Professor JP Brodholt, University College London, Earth Sciences
- Grant held at:
- University College London, Earth Sciences
- Science Area:
- Earth
- Overall Classification:
- Earth
- ENRIs:
- None
- Science Topics:
- Properties Of Earth Materials
- Mantle & Core Processes
- Abstract:
- The Earth's core extends from 3000 km below the surface to the centre of the planet (6370 km) and consists predominantly of an iron-nickel alloy with a few percent of other, lighter, elements. The core is divided into two parts, the outer core which is liquid, and the inner core which is solid. Although the solid inner core is a relatively small part of the planet (less than 1% of the Earth's volume and 2% of its mass) it has a disproportionately large role in the evolution of our planet. For example, while it is well known that the Earth's magnetic field is generated by convection in the liquid outer core, the growth of the solid inner core provides an essential source of energy for the present day magnetic field. As the solid inner core grows (which it must do as the Earth cools) it provides energy from the heat of crystallisation together with chemical buoyancy arising from the enrichment of the outer core with light elements. However, even the most fundamental properties of the Earth's inner core, such as its age and internal structure, are poorly known; most seismic waves do not sample the inner core, and the extreme conditions of pressure and temperature make results from the enormously demanding laboratory experiments unavoidably inconclusive, despite the best efforts of a number of research groups employing state-of-the-art experimental techniques. However, seismic waves, which do traverse the inner core, suggest that the Earth's inner core is anisotropic (i.e. seismic waves travelling through the same part of the core have different velocities depending on the direction they are travelling) and that it is layered (i.e. the deeper inner core has different seismic properties to the outer part of the inner core). The origins of this anisotropy and layering are not at all understood. it is generally considered that the anisotropy reflects the orientation of the crystals present, but this could have arisen either during inner-core crystallisation or developed over time through solid state flow. The observed layering may be due to changes in chemical composition, crystal structure, preferred orientation or some combination of all three. The different hypotheses imply totally different core processes and evolution. The goal of this project is to find a model for the Earth's inner core which is consistent with all the seismic data. This is turn will allow us to constrain the evolution of the core and planet as a whole.
- NERC Reference:
- NE/C519662/1
- Grant Stage:
- Completed
- Scheme:
- Standard Grants Pre FEC
- Grant Status:
- Closed
- Programme:
- Standard Grant
This grant award has a total value of £163,562
FDAB - Financial Details (Award breakdown by headings)
| Total - T&S | Total - Staff | Total - Indirect Costs | Total - Equipment |
|---|---|---|---|
| £6,228 | £106,051 | £48,784 | £2,500 |
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