Selenophysics and models of the lunar three-layered mantle

E. V. Kronrod ; Yu. A. Nefedyev ; V. A. Kronrod ; O. L. Kuskov ; A. O. Andreev

Učënye zapiski Kazanskogo universiteta. Seriâ Fiziko-matematičeskie nauki, Uchenye Zapiski Kazanskogo Universiteta. Seriya Fiziko-Matematicheskie Nauki, Tome 161 (2019) no. 1, pp. 24-38

Résumé

The paper focuses on analyzing the data produced by the modern space missions. The purpose of the work is to analyze the lunar gravitational field and dynamic figure, problem of the lunar core existence and to determine petrologic and geophysical parameters of the composition and structure of the lunar mantle using computer simulation. The analysis of space observations has shown that the real physical figure of the Moon is a more complex system than the model that can be described by a triaxial ellipsoid; at the same time, absolute values and orientation of the inertia moments can be determined neither from space observations nor from ground-based ones. Only the combinations of the inertia moments can be determined. On the basis of the study of trajectories of seismic waves passing and features of their reflection from the lunar inner layers produced by the Apollo mission's seismographs, the composition and structure of the lunar core layers at various depths have been determined. The results of the lunar core studies confirm the hypothesis that the Moon was formed 4.5 billion years ago as a result of the Earth's collision with a large space object. Petrologic and geophysical investigation includes the solution of two problems. The first one is the construction of a three-layered lunar mantle chemical composition model on the basis of a joint inversion of gravitational, seismic, and petrologic and geochemical data. The second problem consists in the revelation of a degree of the mantle reservoirs' chemical homogeneity, namely whether the mantle is homogeneous or stratified by chemical composition with different concentrations of petrogenic elements in various zones of the mantle. Based on the inversion of gravitational and seismic data, inherently coherent models of chemical composition, mineralogy, and lunar three-layered mantle rates have been developed. The results of the simulation have shown that the models of the lunar mantle's thermal state are enriched by SiO$_2$, FeO and depleted by MgO in relation to the primitive Earth's mantle, which indicates the significant distinction between the compositions of the Earth and Moon.

Détail

Keywords: selenophysics, petrology and geochemistry, lunar internal structure models.

Bibliographie

[1] Smith D. E., Zuber M. T., Neumann G. A., Lemoine F. G., “Topography of the Moon from the Clementine lidar”, J. Geophys. Res.: Planets, 102:E1 (1997), 1591–1611 | DOI

[2] Binder A. B., “Lunar Prospector: Overview”, Science, 281:5382 (1998), 1475–1476 | DOI

[3] Sood R., Chappaz L., Melosh H. J., Howell K. C., Milbury C., Blair D. M., Zuber M. T., “Detection and characterization of buried lunar craters with GRAIL data”, Icarus, 289 (2017), 157–172 | DOI

[4] Araki H., Tazawa S., Noda H., Ishihara Y., Goossens S., Sasaki S., Kawano N., Kamiya I., Otake H., Oberst J., Shum C., “Lunar global shape and polar topography derived from Kaguya-LALT laser altimetry”, Science, 323:5916 (2009), 897–900 | DOI

[5] Burchell M. J., Robin-Williams R., Foing B. H., “The SMART-1 lunar impact”, Icarus, 207:1 (2010), 28–38 | DOI

[6] Nefedyev, Y.A., Valeev S. G., Mikeev R. R., Andreev A. O., Varaksina N. Y., “Analysis of data of “Clementine” and “KAGUYA” missions and “ULCN” and “KSC-1162” catalogues”, Adv. Space Res., 50:11 (2012), 1564–1569 | DOI

[7] Williams J. G., Boggs D. H., Ratcliff J. T., “Lunar fluid core moment”, Proc. 41st Lunar and Planetary Sci. Conf., 2010, 2336

[8] Weber R. C., Lin P.-Y., Garnero E. J., Williams Q., Lognonne Ph., “Seismic detection of the lunar core”, Science, 331:6015 (2011), 309–312 | DOI

[9] Moons M., “Physical libration of the Moon”, Celestial Mech., 26:2 (1982), 131–142 | DOI | MR | Zbl

[10] Garcia R. F., Gagnepain-Beyneix J., Chevrot S., Lognonne Ph., “Very preliminary reference Moon model”, Phys. Earth Planet. Inter., 188:1–2 (2011), 96–113 | DOI

[11] Kuskov O. L., Kronrod V. A., Kronrod E. V., “Testing the reference Moon model in respect of the thermal regime and chemical composition of the mantle: Thermodynamics versus seismology”, Izv., Phys. Solid Earth., 52:3 (2016), 344–352 | DOI

[12] Kronrod V. A., Kuskov O. L., “Inversion of seismic and gravity data for the composition and core sizes of the Moon”, Izv., Phys. Solid Earth., 47:8 (2011), 711–730 | DOI

[13] Taylor S. R., Planetary Science: A Lunar Perspective, Lunar and Planetary Institute, Houston, USA, 1982, 481 pp.

[14] Gagnepain-Beyneix J., Lognonne Ph., Chenet H., Lombardi D., Spohnd T., “A seismic model of the lunar mantle and constraints on temperature and mineralogy”, Phys. Earth Planet. Inter., 159:3–4 (2006), 140–166 | DOI

[15] Wieczorek M. A., Neumann G. A., Nimmo F., Kiefer W. S., Taylor G. J., Melosh H. J., Phillips R. J., Solomon S. C., Andrews-Hanna J. C., Asmar S. W., Konopliv A. S., Lemoine F. G., Smith D. E., Watkins M. M., Williams J. G., Zuber M. T., “The crust of the Moon as seen by GRAIL”, Science, 339:6120 (2013), 671–675 | DOI

[16] Williams J., Konopliv A., Boggs D., Park R., Yuan D., Lemoine F., Goossens S., Mazarico E., Nimmo F., Weber R., Asmar S., Melosh H., Neumann G., Phillips R., Smith D., Solomon S., Watkins M., Wieczorek M., Andrews-Hanna J., Head J., Kiefer W., Matsuyama I., McGovern P., Taylor G., Zuber M., “Lunar interior properties from the GRAIL mission”, J. Geophys. Res.: Planets, 119:7 (2014), 1546–1578 | DOI

[17] Kuskov O. L., Kronrod V. A., Kronrod E. V., “Thermo-chemical constraints on the interior structure and composition of the lunar mantle”, Phys. Earth Planet. Inter., 235 (2014), 84–95 | DOI

[18] Khan A., Maclennan J., Taylor S. R., Connolly J. A. D., “Are the Earth and the Moon compositionally alike? Inferences on lunar composition and implications for lunar origin and evolution from geophysical modeling”, J. Geophys. Res.: Planets, 111:E5 (2006), E05005, 1–21 | DOI

[19] Fabrichnaya O. B., Kushov O. L., “Constitution of the mantle. I. Phase relations in the FeO–MgO–SiO2 system at 10–30 GPa”, Phys. Earth Planet. Inter., 69:1–2 (1991), 56–71 | DOI

[20] Kuskov O. L., Galimzyanov R. F., Truskinovsky L. M., Pil'chenko V. A., “Reliability of thermodynamic calculations of chemical and phase equilibria at high pressures and temperatures”, Geokhimiya, 1983, no. 6, 849–871 (In Russian)

[21] Taylor G. J., Wieczorek M. A., “Lunar bulk chemical composition: A post-Gravity Recovery and Interior Laboratory reassessment”, Philos. Trans. R. Soc., A, 372:2024 (2014), 20130242, 1–17 | DOI

[22] Grimm R. E., “Geophysical constraints on the lunar Procellarum KREEP Terrane”, J. Geophys. Res.: Planets, 118:4 (2013), 768–778 | DOI

[23] McDonough W. F., “Constraints on the composition of the continental lithospheric mantle”, Earth Planet. Sci. Lett., 101:1 (1990), 1–18 | DOI

[24] Dyal P., Parkin C., Daily W., “Lunar electrical conductivity, magnetic permeability, and temperature based on the magnetic experiments of the Apollo expeditions”, Cosmochemistry of the Moon and Planets, ed. Vinogradov A. P., Nauka, M., 1975, 323–340

[25] Hood L. L., Jones J. H., “Geophysical constraints on lunar bulk composition and structure: A reassessment”, J. Geophys. Res.: Solid Earth, 92:B4 (1987), E396–E410 | DOI

[26] Williams J.-P., Paige D. A., Greenhagen B. T., Sefton-Nash E., “The global surface temperatures of the Moon as measured by the diviner lunar radiometer experiment”, Icarus, 283 (2017), 300–325 | DOI