UE Physique et chimie de la terre

Diplômes intégrant cet élément pédagogique :

Descriptif

Cette UE propose un tour guidé de l’intérieur de la Terre, cheminant depuis un sketch 1D jusqu’à une représentation complète 3D+temps. Elle présente et explique les processus en jeu, et familiarise avec les outils qui permettent de l’aborder (gravité, sismologie, chaleur, minéralogie, géochimie isotopique).


This class proposes a guided tour of the interior of the Earth, progressing from a 1D sketch to a full 3D+time representation. It presents and explains the processes at work, and provides training with the main tools of investigation (gravity, seismology, heat, mineralogy, cosmochemistry, isotopic geochemistry).

 

Outline of the course
1. Introduction: objectives, outline and organization of the course. Slides, books, journal club, and resources.
Elements, isotopes, abundance of the elements.

1D (radius)
2. Structure of the Earth. Crust, mantle, core, inner core. Mass, gravity, pressure, moment of inertia.
TD: mass, gravity field, pressure, and moment of inertia in a 2-layers Earth.

3. Global seismology. Rays, modes. Fine radial structure of the Earth. Discontinuities, seismic velocities, density, pressure profile.
TD: seismic rays and travel times in a 2-layers Earth.

4. Mineralogy. Rocks, minerals, phase transition, Clapeyron slopes. High pressure high temperature material science. Temperature inside the Earth.
TD: build a rock by melting and crystallization.

1D+t
5. Formation and evolution of the Earth. First age : cosmochemistry, accretion, formation of the Moon, core formation, heavy bombardment, magma ocean.
TD: build a planet…

6. Formation and evolution of the Earth. Geological time : thermal evolution of the Earth. Heat flux, heat sources, heat equation, thermal convection. Crust formation.
TD: The age of the Earth: Kelvin versus Perry.


7. journal club : read and discuss foundation articles.

2D (surface)
8. Plate tectonics. Seismicity, focal mechanisms, spatial geodesy. Ocean spreading, subduction, collision. Forces and stresses. Isostasy.
TD: gravity anomalies and geoid undulations.

9. Magmatic mineralogy. Partial melting, element partitioning. Oceanic and continental crusts.
TD: partial melting (fractional-batch melting)

2D+t
10. Geochronology. Radiogenic isotopes.
TD: creating and using geochrones.

11. Magnetic field. Historical, archeomagnetic, paleomagnetic. polar wander, reversals.
TD: spherical harmonics.

12. Paleogeography. Plate reconstructions. Hotspots. Wilson cycles.
TD: paleogeography with GPlates 2.0.

13. journal club : read and discuss recent articles

3D
14. Isotopes and trace elements : major Earth reservoirs.
TD: databases of geochemical data.

15. Gravity field, geoid, and seismic tomography.
TD: travel-time tomography.

3D+t
15. The dynamic Earth.

Pré-requis

Newton’s laws, Pascal law, harmonic oscillator, geometrical optics, basic thermodynamics.
Basic trigonometry, basic 1D and 2D integrals, barycenter, Gauss theorem

Bibliographie

Teaching books
Elements de Géologie, C. Pomerol et al, 15ème édition, Dunod, 2015.
Physique de la terre solide, observations et théorie, C. Larroque et J. Virieux, Gordon and Breach Science Publisher, 2001.
The Solid Earth - An Introduction to Global Geophysics, C.M.R. Fowler, Cambridge University Press, 2004.
Geochemistry, W.M. White, Wiley-Blackwell, 2012.
Geochemistry, an introduction, F. Albarède, Cambridge University Press, 2003.
Isotope Geology, C.J. Allègre , Cambridge University Press, 2008.
Reference books
Treatise on Geophysics, G. Schubert Ed, 2nd edition, 11 volumes, Elsevier B.V., 2015.
Treatise on Geochemistry, H. Holland & K. Turekian Ed, 2nd edition, 15 volumes, Elsevier B.V., 2014.

Informations complémentaires

Méthode d'enseignement : En présence
Langue(s) : Anglais, Français