The roof depth of the transition zone between upper and lower Earth's mantle
DOI:
https://doi.org/10.15407/dopovidi2018.04.060Keywords:
advection-polymorphic hypothesis, longitudinal seismic waves, mantle, seismicAbstract
The experimental and calculated values of the roof depth of the transition zone between the upper and lower mantle of the Earth are compared. It is proved that this boundary corresponds to the beginning of polymorphic transformations of mantle's rocks. The magnitude of the jump in the velocity of longitudinal seismic waves at a level of 0.45 km/s is estimated. Changes in the depth of the roof due to temperature variations under the influence of the active heat and mass transfer according to the scheme of the advection-polymorphic hypothesis are studied. The approximate correspondence of the results (within the limits of calculation errors) to experimental data in different regions of the continents is demonstrated. Under the oceans, the situation remains uncertain now, mainly due to the differences in the experimental data of different authors.
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References
Gordienko, V. (2015). Essential points of the advection-polymorphism hypothesis. NCGT Journal, No. 2, pp.115-137.
Gordienko, L. & Gordienko, V. (2016). P-wave velocities in the upper mantle beneath oceans. NCGT Journal. 4, No. 3, pp. 389-405.
Yamazaki, A. & Hirahara, K. (1994). The thickness of upper mantle discontinuities, as inferred from shortperiod Jarray data. Geophys. Res. Lett., 21, No. 17, pp. 1811-1814. doi: https://doi.org/10.1029/94GL01418
Flanagan, M. & Shearer, P. (1999). A map of topography on the 410-km discontinuity from PP precursors. Geophys. Res. Lett., 26, No. 5, pp. 549-552. doi: https://doi.org/10.1029/1999GL900036
Priestley, K., Cipar, J., Egorkin, A. & Pavlenkova, N. (1994). Upper-mantle velosity structure beneath Siberian platform. Geophes. J. Int. 118, pp. 309-378. doi: https://doi.org/10.1111/j.1365-246X.1994.tb03968.x
Gossler, J. & Kind, R. (1996). Seismic evidence for very deep roots of continents. Earth Plan. Sc. Lett., 138, pp. 113. doi: https://doi.org/10.1016/0012-821X(95)00215-X
Melbourne, T. & Yelmberger, D. (1998). Fine structure of the 410-km discontinuity. J. Geophys. Res., 103, No. B5, pp. 10091-10102. doi: https://doi.org/10.1029/98JB00164
Frost, D. J. (2008). The upper mantle and transition zone. Elements. 4, pp. 171-176. doi: https://doi.org/10.2113/GSELEMENTS.4.3.171
Gu, Y. J., Zhang, Y., Sacchi, M. D, Chen, Y. & Contenti, S. (2015). Sharp mantle transition from cratons to Cordillera in southwestern Canada. J. Geophys. Res. Solid Earth., 120, pp. 5051-5069. doi: https://doi.org/10.1002/2014JB011802
Houser, C. & Williams, Q. (2010). Reconciling Pacific 410 and 660 km discontinuity topography, transition zone shear velocity patterns, and mantle phase transitions. Earth Planet. Sci. Lett., 296, pp. 255-266. doi: https://doi.org/10.1016/j.epsl.2010.05.006
Julia, J. & Nyblade, A. (2013). Probing the upper mantle transition zone under Africa with P520s conversions: Implications for temperature and composition. Earth Planet. Sci. Lett., 368, pp. 151-162. doi: https://doi.org/10.1016/j.epsl.2013.02.021
Swieczak, M., Grad, M., TOR & SVEKALAPKO Working Groups. (2004). Upper mantle seismic discontinuities topography variations beneath eastern Europe. Acta Geophys. Pol., 52, No. 3, pp.251-270.
Tauzin, B., Debayle, E. & Wittlinger, G. Constraints on the mantle transition zone structure from P-to-Sv converted waves. Retrieved from http://www.mantleplumes.org/TransitionZone3.html
Tauzin, B., van der Hilst, D., Wittlinger, G. & Ricard, Y. (2013). Multiple transition zone seismic discontinuities and low velocity layers below western United States. J. Geophys. Res. Solid Earth., 118, pp.2307-2322. doi: https://doi.org/10.1002/jgrb.50182
Thomas, Ñ. & Billen, M. (2009). Mantle transition zone structure along a profile in the SW Pacific: Thermal and compositional variations. Geophys. J. Int., 176, Iss. 1, pp.113-125. doi: https://doi.org/10.1111/j.1365-246X.2008.03934.x
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