Earth:Magma ocean

From HandWiki

Magma oceans exist during periods of Earth's or any planet's accretion when the planet is completely or partly molten.[1] In the early Solar System, energy to melt objects came largely from the decay of radioactive aluminium-26.[1] As planets grew larger, the energy was supplied from large or giant impacts.[2] During its formation, the Earth likely suffered a series of magma oceans resulting from giant impacts,[3] the final one being the Moon-forming impact.[4]

The formation of the lunar magma ocean which was a layer of molten rock believed to measure hundreds of kilometers in depth.[1]

Magma oceans are integral parts of planetary formation as they facilitate formation of a core through metal segregation[5] and an atmosphere and hydrosphere through degassing.[6] Magma oceans may survive for millions to tens of millions of years, interspersed by relatively clement conditions.

Magma oceans are widely accepted to have existed on Earth, and the best chemical evidence for them is the abundance of certain siderophile elements in the mantle that record magma ocean depths of approximately 1000 km during accretion.[7][8] A magma ocean also occurred on the Moon during and following its formation.[4]

See also

References

  1. 1.0 1.1 1.2 Elkins-Tanton, Linda T. (2012-01-01). "Magma Oceans in the Inner Solar System". Annual Review of Earth and Planetary Sciences 40 (1): 113–139. doi:10.1146/annurev-earth-042711-105503. Bibcode2012AREPS..40..113E. 
  2. Tonks, W. Brian; Melosh, H. Jay (1993-03-25). "Magma ocean formation due to giant impacts" (in en). Journal of Geophysical Research: Planets 98 (E3): 5319–5333. doi:10.1029/92JE02726. ISSN 2156-2202. Bibcode1993JGR....98.5319T. 
  3. Tucker, Jonathan M.; Mukhopadhyay, Sujoy (2014-05-01). "Evidence for multiple magma ocean outgassing and atmospheric loss episodes from mantle noble gases". Earth and Planetary Science Letters 393: 254–265. doi:10.1016/j.epsl.2014.02.050. Bibcode2014E&PSL.393..254T. 
  4. 4.0 4.1 Barr, Amy C. (2016-09-21). "On the origin of Earth's Moon: ORIGIN OF EARTH'S MOON" (in en). Journal of Geophysical Research: Planets 121 (9): 1573–1601. doi:10.1002/2016JE005098. http://doi.wiley.com/10.1002/2016JE005098. 
  5. Rubie, D. C.; Nimmo, F.; Melosh, H. J. (2007-01-01). Formation of Earth's Core. Amsterdam: Elsevier. pp. 51–90. doi:10.1016/B978-044452748-6.00140-1. ISBN 9780444527486. 
  6. Zahnle, Kevin; Arndt, Nick; Cockell, Charles; Halliday, Alex; Nisbet, Euan; Selsis, Franck; Sleep, Norman H. (2007-01-01). Fishbaugh, Kathryn E.. ed (in en). Emergence of a Habitable Planet. Space Sciences Series of ISSI. Springer New York. pp. 35–78. doi:10.1007/978-0-387-74288-5_3. ISBN 9780387742878. Bibcode2007ghtp.book...35Z. 
  7. Li, Jie; Agee, Carl B. (1996-06-20). "Geochemistry of mantle–core differentiation at high pressure" (in en). Nature 381 (6584): 686–689. doi:10.1038/381686a0. Bibcode1996Natur.381..686L. 
  8. Righter, K.; Drake, M. J.; Yaxley, G. (1997-03-01). "Physical and Chemical Evolution of the EarthPrediction of siderophile element metal-silicate partition coefficients to 20 GPa and 2800°C: the effects of pressure, temperature, oxygen fugacity, and silicate and metallic melt compositions". Physics of the Earth and Planetary Interiors 100 (1): 115–134. doi:10.1016/S0031-9201(96)03235-9. Bibcode1997PEPI..100..115R.