Presentation on theme: "Jean-Claude Mareschal Fiona Darbyshire. Course outline Age and formation of Earth and planets. Origin of the elements. Formation of the moon. The early."— Presentation transcript:
Course outline Age and formation of Earth and planets. Origin of the elements. Formation of the moon. The early Earth. Geochronology. (JCM) Shape and rotation of the Earth. Tides. (JCM) The gravity field of Earth. Gravity anomalies. Isostasy. (JCM) Heat flow, thermal regime, and the energy budget of the Earth. (JCM) Earth’s magnetic field. The geodynamo. (JCM) Seismic wave propagation. Body and surface waves. Free oscillations. (FD) Seismicity of the Earth. Earthquake focal mechanisms. (FD) Plate tectonics. (FD) Seismic tomography: implications for geodynamics and mantle convection. (FD)
Course objectives What do we want to know about Earth interior? Physical properties (density, elastic properties, viscosity, electrical conductivity, …) Pressure, temperature at depth Chemical composition Physical state (liquid, solid) Equation of state How did it come to be what it is today? How does it work?
Some references Davies, G. F. Dynamic Earth: Plates, Plumes and Mantle Convection, Cambridge University Press, 2000. Fowler, CMR, The Solid Earth: An Introduction to Global Geophysics, 2nd Edition, Cambridge, University Press, 2004. Stacey, F.D., and Davis, P., Physics of the Earth, 4th Edition, Cambridge University Press, 2008. Bott, M.H.P. The interior of the Earth, 2 nd Edition, Edward Arnold, London, 1982
Units. Numbers. SI unitPractical unitConversion factor lengthmLight year Parsec 1 LY= 10 13 km 1 pc = 3.1 10 13 km Masskg Timesyr1 yr = 3.15 10 7 s accelerationms -2 Gal (cm s -2 ), mGal1 mGal = 10 -5 ms -2 ForceN (kg m s -2 ) EnergyJ (kg m 2 s -2 )Calorie1 cal =4.18J PowerW (J s -1 ) PressurePa (N m -2 )bar, kbar1 kbar= 10 8 Pa ViscosityPa spoise1 poise = 0.1 Pa s TemperatureKdeg CT(C)= 273 +T(K)
Physical constants. c300,000 km s -1 G6.67 10 -11 N m 2 kg -2 N A (Avogadro)6.02 10 23 mol -1 R (Gaz constant)8.31 J mol -1 K -1 k (Boltzman) = R/N A 1.38 10 -23 J K -1
Numbers. Mass Earth5.97 10 24 kg Mean density5,515 kg m -3 Mass Sun/Mass Earth332,947 Mass Earth/Mass Moon81 Solar density1,408 kg m -3 Moon density3.341 kg m -3
Numbers. Distance Earth radius~6,400 km Earth-Moon~400,000 km Earth-Sun~150 10 6 km (8 min) Nearest star~ 4 LY Galaxy100,000 LY Nearest galaxy1,000,000 LY Universe10 10 LY Time Atomic unit10 -15 s Solar day86,400 s Astronomical day86,146 s Last glaciation10,000 yr Man2-4 Myr Earth4.5 Gyr Universe~15 Gyr