Earth:List of unsolved problems in geoscience

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This list provides references to notable unsolved problems in geoscience.

The early Earth and the Solar System

  • Was there ever a collision of the Earth with another planet Theia, giving birth to the Moon?[1] There is compelling evidence, such as measures of a shorter duration of the Earth's rotation and lunar month in the past, pointing to a Moon much closer to Earth during the early stages of the Solar System.[2]
  • What is the long-term heat balance of Earth? How did its internal temperature decay since it formed by accretion of chondrites? How abundant are radiogenic elements in the interior? Did a "faint young Sun" ever warm a "snowball Earth"?[3][4]

Topography and environment

  • Can the now widely available topographic data be used to derive past tectonic and climatic conditions (in the multi-million year scale)? Do we know enough about the erosion and transport processes? Does the stochasticity of meteorological and tectonic events reflect in the landscape? How much has life contributed to shape the Earth's surface?[citation needed]
  • Can classical geomorphological concepts such as peneplanation or retrogressive erosion be quantitatively understood? Old mountain ranges such as the Appalachian or the Urals seem to retain relief for >108 years, while subglacial fluvial valleys under Antarctica are preserved under moving ice of kilometric thickness since the Neogene. What controls the time-scale of topographic decay?[5]
  • What are the erosion and transport laws governing the evolution of the Earth's Surface?[6] Rivers transport sediment particles that are at the same time the tools for erosion but also the shield protecting the bedrock. How important is this double role of sediment for the evolution of landscapes?[7][8]
  • How resilient is the ocean to chemical perturbations?[citation needed]
  • What controls the dynamics of storm tracks?[9]
  • Mechanisms that cause oscillations in equatorial climate remain under intense study. The El Nino Southern Oscillation (ENSO) of the equatorial Pacific Ocean temperature is difficult to predict more than a few months in advance. The Quasi-Biennial Oscillation (QBO) of the equatorial stratospheric winds is somewhat regular at ~28 months but the cause has been heavily debated. Are these stochastic, chaotic, or deterministically forced behaviors?[citation needed]
  • What are skyquakes?[citation needed]
  • What causes Hessdalen lights?[10]

Structure of crust, mantle, and core

  • The 'space problem': How are granite magma chambers emplaced in the crust?[11] What are the structures and locations of the magmatic systems that might cause supervolcanoes? What are the viscosities and densities of the magma chambers and the details of magma migration?[12]
  • What are the non-uniformities and rheological details of the mantle? What is the structure of the 660 km discontinuity and its relation to the correct model of the polar drift?[13]
  • What is the precise nature of chemical heterogeneity associated with the Gutenberg discontinuity?[14]
  • What are the light alloying elements in the Earth's outer core and how are they distributed?[15][16] What are the heterogeneities of the core and their dynamical significance?[16]
  • Does the internal mantle structure provide the resonance for the Chandler wobble of the Earth's axis or is it some other external mechanism? No available motions seem to be coherent drivers for the wobble period of 433 days.[citation needed]

References

  1. Canup, R. M. (17 October 2012). "Forming a Moon with an Earth-like Composition via a Giant Impact". Science 338 (6110): 1052–1055. doi:10.1126/science.1226073. PMID 23076098. Bibcode2012Sci...338.1052C. 
  2. George, Williams (1991). "Upper Proterozoic Tidal Rhythmites, South Australia: Sedimentary Features, Deposition, and Implications for the Earth's Paleorotation". Clastic Tidal Sedimentology: 161–177. http://archives.datapages.com/data/cspg_sp/data/016/016001/161_cspgsp0160161.htm. Retrieved 3 March 2015. 
  3. Wired: Was the Earth a migratory planet?
  4. Marty, B.; Zimmermann, L.; Pujol, M.; Burgess, R.; Philippot, P. (19 September 2013). "Nitrogen Isotopic Composition and Density of the Archean Atmosphere". Science 342 (6154): 101–104. doi:10.1126/science.1240971. PMID 24051244. Bibcode2013Sci...342..101M. 
  5. Egholm, David L.; Knudsen, Mads F.; Sandiford, Mike (26 June 2013). "Lifespan of mountain ranges scaled by feedbacks between landsliding and erosion by rivers". Nature 498 (7455): 475–478. doi:10.1038/nature12218. PMID 23803847. Bibcode2013Natur.498..475E. 
  6. Willenbring, Jane K.; Codilean, Alexandru T.; McElroy, Brandon (2013). "Earth is (mostly) flat: Apportionment of the flux of continental sediment over millennial time scales". Geology 41 (3): 343–346. doi:10.1130/G33918.1. Bibcode2013Geo....41..343W. https://ro.uow.edu.au/cgi/viewcontent.cgi?article=2524&context=smhpapers. 
  7. Sklar, Leonard S.; Dietrich, William E. (2001). "Sediment and rock strength controls on river incision into bedrock". Geology 29 (12): 1087. doi:10.1130/0091-7613(2001)029<1087:SARSCO>2.0.CO;2. Bibcode2001Geo....29.1087S. http://eps.berkeley.edu/~bill/papers/105.pdf. Retrieved 3 March 2015.  (effect description and tools)
  8. Cowie, Patience A.; Whittaker, Alexander C.; Attal, Mikaël; Roberts, Gerald; Tucker, Greg E.; Ganas, Athanassios (2008). "New constraints on sediment-flux–dependent river incision: Implications for extracting tectonic signals from river profiles". Geology 36 (7): 535. doi:10.1130/G24681A.1. Bibcode2008Geo....36..535C. http://www.geos.ed.ac.uk/research/globalchange/group3/Apenninesproj/Cowie_et_al_2008.pdf. Retrieved 3 March 2015. (field example)
  9. Bony, Sandrine et al. (2015). "Clouds, circulation and climate sensitivity". Nature Geoscience 8 (4): 261–268. doi:10.1038/ngeo2398. Bibcode2015NatGe...8..261B. http://centaur.reading.ac.uk/39925/1/FourQuestions_withFigures_Revised_ngeo_jan27.pdf. 
  10. Caron, Etienne; Faridi, Pouya (2016). "To Investigate or Not to Investigate? Researchers' Views on Unexplored Atmospheric Light Phenomena". Frontiers in Earth Science 4: 17. doi:10.3389/feart.2016.00017. ISSN 2296-6463. Bibcode2016FrEaS...4...17C. 
  11. Björkgren, Maria (2017). The Formation of Granite Magma Chambers in the Mourne Mountains, Northern Ireland. http://www.diva-portal.org/smash/record.jsf?pid=diva2%3A1114406&dswid=5620. 
  12. Kaus, B. J. P.; Reuber, G. S.; Popov, A.; Baumann, T. (2018). "Understanding the Yellowstone magmatic system using 3D geodynamic inverse models". In: Geophysical Research Abstracts. 20. //meetingorganizer.copernicus.org/EGU2018/EGU2018-15184.pdf. 
  13. Lowrie, William (2007). Fundamentals of geophysics (2nd ed.). Cambridge University Press. p. 117. ISBN 9781139465953. https://books.google.com/books?id=h2-NjUg4RtEC&pg=PA117. 
  14. Hirose, Kei; Karato, Shun‐ichiro; Cormier, Vernon F.; Brodholt, John P.; Yuen, David A. (2006). "Unsolved problems in the lowermost mantle". Geophysical Research Letters 33 (12): L12S01. doi:10.1029/2006GL025691. Bibcode2006GeoRL..3312S01H. http://discovery.ucl.ac.uk/98973/1/2006GL025691.pdf. 
  15. Zhang, Y.; Sekine, T.; He, H.; Yu, Y.; Liu, F.; Zhang, M. (2016). "Experimental constraints on light elements in the Earth's outer core". Scientific Reports 6: 22473. doi:10.1038/srep22473. PMID 26932596. Bibcode2016NatSR...622473Z. 
  16. 16.0 16.1 Olson, P. (December 2016). "A Mission to Earth's Center". American Geophysical Union, Fall General Assembly 2016, Abstract Id. DI23C-08 2016: DI23C–08. Bibcode2016AGUFMDI23C..08O. 

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