Earth's Water Budget and Hydrogen's Impact on Olivine

1. LEGENDE lien hiérarchique (hyperonyme, hyponyme) lien partitif stockage de l’eau dans lien cause-effet lien effet-cause processus lien spatial lien temporel objet d’étude affectée par la présence d’hydrogène dans l’olivine polymorphe Les termes en rouge font l’objet d’une fiche courte dans le dictionnaire terminologique et les termes en bleu font l’objet d’une fiche longue. Les termes soulignés font l’objet d’une arborescence développée.

2. Earth’s water budget: Earth’s water reservoir* external reservoir external reservoir volatile components in the atmosphere hydrosphere oceans lakes rivers water tables glaciers *Il peut s’agir à la fois d’un lien hiérarchique et d’un lien partitif car les réservoirs interne et externe sont deux types de réservoir mais on peut également dire que les réservoirs d’eau sur Terre se composent d’un réservoir interne et d’un réservoir externe.

3. internal reservoir mantle core crust + upper mantle transition zone lower mantle lithosphere continental lithosphere oceanic lithosphere sediments minerals fluid • as a –OH radical • as H+ ion • as H2O mole nominally anhydrous minerals nominally hydrous minerals … serpentine garnet mica pyroxene olivine wadsleyite … periclase amphibole majorite orthopyroxene clinopyroxene ringwoodite

4. Hydrogen’s entrance in the mantle hydrothermalism oceanic lithosphere hydration subduction hydrogen enters the mantle hydrogen injection into the internal reservoir hydrogen ascent hydrogen release at 150 km depth hydrogen diffusion inminerals

5. diffusionof hydrogen in minerals nominally hydrous minerals nominally anhydrous minerals atomic diffusion ionic diffusion charge defect inclusion point defect ion H+ incorporates in charge defect divalent cation substitutes for an hydrogen atom charge defect associate with point defect fluid inclusion glass inclusion hydrogen atom associate with oxygen atom ion H+ associates with oxygen atom formation of an hydroxyl group formation of an hydroxyl group

6. Special case: olivine hydrogen diffusion in olivine physical property of olivine rock transformation tectonics phase equilibrium metamorphism electrical conductivity dehydration metasomatism equation of state anisotropy

7. Earth’s sciences … geophysics … internal geophysics external geophysics tectonics geostatistics seismology … geodynamics rheology plate tectonics partial melting deformation convection magma genesis subduction

8. Effect of hydrogen diffusion in olivine on rheology hydrogen diffusion in olivine lower viscosity ductile deformation brittle deformation lithospherefracture into plates creep fold shear zone plate tectonics fault

9. Effect of hydrogen diffusion in olivine on partial melting hydrogen diffusion in olivine no hydrogen diffusion in olivine hydrouspartial melting anhydrous partial melting magmas production dehydration of generated magmas volcanism magma eruption pressure increase continental and oceanic crust formation deep earthquake micro-earth quake permeability

10. Effect of hydrogen diffusion in olivine on magma genesis hydrogen diffusioninolivine decrease of liquidus temperature and increase of solidus temperature rocks melting magma genesis ultramafic magma

11. Effect of hydrogen diffusion in olivine on convection nohydrogen diffusioninolivine hydrogen diffusioninolivine convection instabilities convection subduction instabilities lithosphere does not cool the mantle sufficiently subduction partial melting instabilities

12. Reminder: plate tectonics convection convergence divergence transcurrence subduction collision obduction oceanic accretion continental rif orogeny orogeny mid-ocean ridge fault + + oceanic trench island arc + island arc volcanism

13. Reminder: subduction 2 oceanic plates converge an oceanic plate and a continental plate converge the heavier plate subducts oceanic plate subducts lithosphere ingestion lithosphere ingestion partial melting partial melting magma genesis magma genesis a part of the magma remains in the asthenosphere island arc a part of the magma remains in the asthenosphere island arc + + orogeny orogeny + + oceanic trench oceanic trench