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1. The habitability of a stagnant-lid Earth

Author

Tosi, N., Godolt, M., Stracke, B., Ruedas, T., Grenfell, J. L., Höning, D., Nikolaou, A., Plesa, A. -C., Breuer, D., and Spohn, T.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

Plate tectonics is a fundamental component for the habitability of the Earth. Yet whether it is a recurrent feature of terrestrial bodies orbiting other stars or unique to the Earth is unknown. The stagnant lid may rather be the most common tectonic expression on such bodies. To understand whether a stagnant-lid planet can be habitable, i.e. host liquid water at its surface, we model the thermal evolution of the mantle, volcanic outgassing of H$_2$O and CO$_2$, and resulting climate of an Earth-like planet lacking plate tectonics. We used a 1D model of parameterized convection to simulate the evolution of melt generation and the build-up of an atmosphere of H$_2$O and CO$_2$ over 4.5 Gyr. We then employed a 1D radiative-convective atmosphere model to calculate the global mean atmospheric temperature and the boundaries of the habitable zone (HZ). The evolution of the interior is characterized by the initial production of a large amount of partial melt accompanied by a rapid outgassing of H$_2$O and CO$_2$. At 1 au, the obtained temperatures generally allow for liquid water on the surface nearly over the entire evolution. While the outer edge of the HZ is mostly influenced by the amount of outgassed CO$_2$, the inner edge presents a more complex behaviour that is dependent on the partial pressures of both gases. At 1 au, the stagnant-lid planet considered would be regarded as habitable. The width of the HZ at the end of the evolution, albeit influenced by the amount of outgassed CO$_2$, can vary in a non-monotonic way depending on the extent of the outgassed H$_2$O reservoir. Our results suggest that stagnant-lid planets can be habitable over geological timescales and that joint modelling of interior evolution, volcanic outgassing, and accompanying climate is necessary to robustly characterize planetary habitability.

Published
2017
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2. Mercury's Crustal Porosity as Constrained by the Planet's Bombardment History.

Author

Broquet, A., Rolser, F., Plesa, A. C., Breuer, D., and Hussmann, H.

Subjects
AERODYNAMIC heating, PLANETARY crusts, STANDARD deviations, POROSITY, PLANETARY interiors, LUNAR craters
Abstract

Knowing the structure of the crust is critical to understanding a planet's geologic evolution. Crustal thickness inversions rely on bulk density estimates, which are primarily affected by porosity. Due to the absence of high‐resolution gravity data, Mercury's crustal porosity has remained unknown. Here, we use a model that was calibrated to the Moon to relate Mercury's impact crater population and long‐wavelength crustal porosity in the cratered terrains. Therein, porosity is created by large impacts and then decreased as the surface ages due to pore compaction by smaller impacts and overburden pressure. Our models fit independent gravity‐derived porosity estimates in the northern regions, where data is well resolved. Porosity in the cratered terrains is found to be 9%–18% with an average and standard deviation of 13% ± $\pm $ 2%, indicating lunar‐like crustal bulk densities of 2,565 ± $\pm $ 70 kg m−3 ${\mathrm{m}}^{-3}$ from which updated crustal thickness maps are constructed. Plain Language Summary: The crust of a planet is a thermal barrier, which controls how fast heat escapes to space. Depending on its thickness, the crust can strongly insulate the planet's interior preventing efficient cooling. Therefore, knowing the structure of the crust is critical to unraveling the geologic history of planetary bodies. Crustal thickness is typically inverted from gravity and topography data. One critical parameter for these inversions is the bulk density of the crust, which is primarily driven by porosity variations. While high‐resolution gravity field mapping allowed constraining the bulk density and porosity of the lunar crust, crustal porosity on other planetary bodies has remained unknown. In this work, we use a model that was calibrated to the Moon to relate Mercury's impact crater population and long‐wavelength crustal porosity in the cratered terrains. We show that crustal porosity in the cratered terrains ranges from 9% to 18% with an average and standard deviation of 13% ± $\pm $ 2%, indicating lunar‐like low bulk densities of 2,565 ± $\pm $ 70 kg m−3 ${\mathrm{m}}^{-3}$. Key Points: Mercury's crustal porosity estimated from the crater population, assuming porosity formed by large impacts and decreased with surface agingCrustal porosity in the cratered terrains ranges from 9% to 18% with an average and standard deviation of 13% ± 2%The low bulk density of Mercury's crust in the cratered terrain, 2,565 ± 70 kg m−3, is similar to that of the lunar highlands [ABSTRACT FROM AUTHOR]

Published
2024
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3. Mars Soil Temperature and Thermal Properties From InSight HP3 ${\mathrm{H}\mathrm{P}}^{3}$ Data.

Author

Spohn, T., Müller, N., Knollenberg, J., Grott, M., Golombek, M. P., Plesa, A.‐C., Bickel, V. T., Morgan, P., Krause, C., Breuer, D., Smrekar, S. E., and Banerdt, W. B.

Subjects
CHEMICAL processes, SOIL temperature, THERMAL conductivity, THERMAL properties, SURFACE temperature, THERMAL diffusivity
Abstract

Diurnal and seasonal variations in soil and surface temperature measured with the HP3 ${\mathrm{H}\mathrm{P}}^{3}$ thermal probe and radiometer of NASA's InSight Mars mission are reported. At a representative depth of 10–20 cm, an average temperature of 217.5 K was found, varying by 5.3–6.7 K during a sol and by 13.3 K during the seasons. From the damping of the temperature variation with depth and the phase shift, a thermal diffusivity of (3.93 ± $\pm $ 0.39) × 10−8 ${10}^{-8}$m2 ${\mathrm{m}}^{2}$/s was derived for the upper ∼ ${\sim} $10 cm from the diurnal temperature variation and of (3.63 ± $\pm $ 0.53) × 10−8 ${10}^{-8}$m2 ${\mathrm{m}}^{2}$/s for the ∼ ${\sim} $40 cm depth range of the mole from the annual temperature variation. Using published thermal conductivity and inertia values together with the diffusivities, soil densities of 1,470 and 1,730 kg/m3 ${m}^{3}$ were derived for these depths. The temperatures allow the deliquescence of thin films of brine, the efflorescence of which may explain the cemented duricrust observed. Plain Language Summary: Temperature is an important factor in understanding the physical properties of Martian soil. It determines how quickly physical processes and chemical reactions occur, including the transport of heat and materials. Temperature is crucial to astrobiology because it affects the habitability of the soil and the potential for water or brine to support microbial life. We measured the temperature in the soil during several Martian days and over a Martian year using the NASA InSight Mars mission's Heat Flow and Physical Properties Package. The average temperature was −56°C (217.5 K) over the depth extent of the thermal probe, which was about 40 cm. The temperature varied by 5–7° during the day, which is only a tenth of the daily surface temperature variation. It varied by 13° during the seasons. The temperature is subfreezing for water, but it allows the formation of thin films of salty brine for 10 hr or more during a Martian day. The solidification of the brine is a likely explanation for the observed few tens of centimeters thick duricrust, a layer of consolidated, cohesive sand, which is thought to have hampered the penetration to greater depth of the mission's thermal probe. Key Points: We measured the temperature and its diurnal and annual variations in the top 40 cm of the Martian soil at the InSight landing siteThe soil thermal diffusivity was calculated from the diurnal and seasonal surface and soil temperature variationsThe soil temperature allows the formation of thin films of brine; their efflorescence may explain the formation of the observed duricrust [ABSTRACT FROM AUTHOR]

Published
2024
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4. Can a fractionally crystallized magma ocean explain the thermo-chemical evolution of Mars?

Author

Plesa, A. -C., Tosi, N., and Breuer, D.

Subjects
Astrophysics - Earth and Planetary Astrophysics, Physics - Geophysics
Abstract

The impact heat accumulated during the late stage of planetary accretion can melt a significant part or even the entire mantle of a terrestrial body, giving rise to a global magma ocean. [...] Assuming fractional crystallization of the magma ocean, dense cumulates are produced close to the surface, largely due to iron enrichment in the evolving magma ocean liquid (Elkins-Tanton et al., 2003). A gravitationally unstable mantle thus forms, which is prone to overturn. We investigate the cumulate overturn and its influence on the thermal evolution of Mars using mantle convection simulations in 2D cylindrical geometry. We present a suite of simulations using different initial conditions and a strongly temperature-dependent viscosity. We assume that all radiogenic heat sources have been enriched during the freezing-phase of the magma ocean in the uppermost 50 km and that the initial steam-atmosphere created by the degassing of the freezing magma ocean was rapidly lost, implying that the surface temperature is set to present-day values. In this case, a stagnant lid forms rapidly on top of the convective interior preventing the uppermost dense cumulates to sink, even when allowing for a plastic yielding mechanism. Below this dense stagnant lid, the mantle chemical gradient settles to a stable configuration. The convection pattern is dominated by small-scale structures, which are difficult to reconcile with the large-scale volcanic features observed over Mars' surface and partial melting ceases in less than 900 Ma. Assuming that the stagnant lid can break because of additional mechanisms and allowing the uppermost dense layer to overturn, a stable density gradient is obtained, with the densest material and the entire amount of heat sources lying above the CMB. This stratification leads to a strong overheating of the lowermost mantle [...], Comment: 30 pages, 5 figures, 1 table, submitted to EPSL

Published
2014
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5. Constraints on the shallow elastic and anelastic structure of Mars from InSight seismic data

Author

Lognonné, P., Banerdt, W. B., Pike, W. T., Giardini, D., Christensen, U., Garcia, R. F., Kawamura, T., Kedar, S., Knapmeyer-Endrun, B., Margerin, L., Nimmo, F., Panning, M., Tauzin, B., Scholz, J.-R., Antonangeli, D., Barkaoui, S., Beucler, E., Bissig, F., Brinkman, N., Calvet, M., Ceylan, S., Charalambous, C., Davis, P., van Driel, M., Drilleau, M., Fayon, L., Joshi, R., Kenda, B., Khan, A., Knapmeyer, M., Lekic, V., McClean, J., Mimoun, D., Murdoch, N., Pan, L., Perrin, C., Pinot, B., Pou, L., Menina, S., Rodriguez, S., Schmelzbach, C., Schmerr, N., Sollberger, D., Spiga, A., Stähler, S., Stott, A., Stutzmann, E., Tharimena, S., Widmer-Schnidrig, R., Andersson, F., Ansan, V., Beghein, C., Böse, M., Bozdag, E., Clinton, J., Daubar, I., Delage, P., Fuji, N., Golombek, M., Grott, M., Horleston, A., Hurst, K., Irving, J., Jacob, A., Knollenberg, J., Krasner, S., Krause, C., Lorenz, R., Michaut, C., Myhill, R., Nissen-Meyer, T., ten Pierick, J., Plesa, A.-C., Quantin-Nataf, C., Robertsson, J., Rochas, L., Schimmel, M., Smrekar, S., Spohn, T., Teanby, N., Tromp, J., Vallade, J., Verdier, N., Vrettos, C., Weber, R., Banfield, D., Barrett, E., Bierwirth, M., Calcutt, S., Compaire, N., Johnson, C.L., Mance, D., Euchner, F., Kerjean, L., Mainsant, G., Mocquet, A., Rodriguez Manfredi, J. A, Pont, G., Laudet, P., Nebut, T., de Raucourt, S., Robert, O., Russell, C. T., Sylvestre-Baron, A., Tillier, S., Warren, T., Wieczorek, M., Yana, C., and Zweifel, P.

Published
2020
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7. Results From Insight’s First Full Martian Year

Author

Wieczorek, M, Weber, R, Warner, N, Tromp, J, Teanby, N, Stanley, S, Stahler, S, Spohn, T, Spiga, A, Siegler, M, Schmerr, N, Rodriguez-Manfredi, P.J.A, Plesa, A.-C, Pike, W.T, Nimmo, Francis, Newman, C, Nagihara, S, Müller, N, Morgan, P, Mittelholz, A, Mimoun, D, Michaut, C, McLennan, S, Margerin, L, Maki, J, Lorenz, R, Lognonné, P, Lemmon, M, Knapmeyer-Endrun, B, King, S, Khan, A, Kedar, S, Kawamura, Taichi, Kargl, G, Joshi, R, Johnson, C, Irving, J, Hudson, T, Grygorczuk, J, Grott, M, Grant, J, Golombek, M, Giardini, D, Garvin, J, Garcia, R, Folkner, W, Fillingim, M, Dehant, V, Daubar, I, Collins, G, Clinton, J, Christensen, U, Chi, P, Ceylan, S, Brinkman, N, Bozdag, Ebru, Bowles, Neil, Bissig, F, Beucler, E, Beghein, C, Banfield, D, Asmar, S, Antonangeli, D, Smrekar, S, Banerdt, W. B, and Panning, M.P

Published
2021

8. Results From Insight’s First Full Martian Year

Author

Panning, M.P, Banerdt, W. B, Smrekar, S, Antonangeli, D, Asmar, S, Banfield, D, Beghein, C, Beucler, E, Bissig, F, Bowles, Neil, Bozdag, Ebru, Brinkman, N, Ceylan, S, Chi, P, Christensen, U, Clinton, J, Collins, G, Daubar, I, Dehant, V, Fillingim, M, Folkner, W, Garcia, R, Garvin, J, Giardini, D, Golombek, M, Grant, J, Grott, M, Grygorczuk, J, Hudson, T, Irving, J, Johnson, C, Joshi, R, Kargl, G, Kawamura, Taichi, Kedar, S, Khan, A, King, S, Knapmeyer-Endrun, B, Lemmon, M, Lognonné, P, Lorenz, R, Maki, J, Margerin, L, McLennan, S, Michaut, C, Mimoun, D, Mittelholz, A, Morgan, P, Müller, N, Nagihara, S, Newman, C, Nimmo, Francis, Pike, W.T, Plesa, A.-C, Rodriguez-Manfredi, P.J.A, Schmerr, N, Siegler, M, Spiga, A, Spohn, T, Stahler, S, Stanley, S, Teanby, N, Tromp, J, Warner, N, Weber, R, and Wieczorek, M

Published
2021

9. The next frontier for planetary and human exploration

Author

Stamenković, V., Beegle, L. W., Zacny, K., Arumugam, D. D., Baglioni, P., Barba, N., Baross, J., Bell, M. S., Bhartia, R., Blank, J. G., Boston, P. J., Breuer, D., Brinckerhoff, W., Burgin, M. S., Cooper, I., Cormarkovic, V., Davila, A., Davis, R. M., Edwards, C., Etiope, G., Fischer, W. W., Glavin, D. P., Grimm, R. E., Inagaki, F., Kirschvink, J. L., Kobayashi, A., Komarek, T., Malaska, M., Michalski, J., Ménez, B., Mischna, M., Moser, D., Mustard, J., Onstott, T. C., Orphan, V. J., Osburn, M. R., Plaut, J., Plesa, A.-C., Putzig, N., Rogers, K. L., Rothschild, L., Russell, M., Sapers, H., Lollar, B. Sherwood, Spohn, T., Tarnas, J. D., Tuite, M., Viola, D., Ward, L. M., Wilcox, B., and Woolley, R.

Published
2019
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10. Global Crustal Thickness Revealed by Surface Waves Orbiting Mars

Author

Kim, D., primary, Duran, C., additional, Giardini, D., additional, Plesa, A.‐C., additional, Stähler, S. C., additional, Boehm, C., additional, Lekić, V., additional, McLennan, S. M., additional, Ceylan, S., additional, Clinton, J. F., additional, Davis, P., additional, Khan, A., additional, Knapmeyer‐Endrun, B., additional, Panning, M. P., additional, Wieczorek, M., additional, Lognonné, P., additional, and Banerdt, W. B., additional

Published
2023
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11. First observations of core-transiting seismic phases on Mars

Author

Irving, J. C. E., Lekic, V., Durán, C., Drilleau, M., Kim, D., Rivoldini, A., Khan, A., Samuel, H., Antonangeli, D., Bruce Banerdt, W., Beghein, C., Bozdagk, E., Ceylan, S., Charalambous, C., Clinton, J., Davis, P., Garcia, R., Giardini, D., Catherine Horleston, A., Huang, Q., Hurst, K. J., Kawamura, T., King, Scott D., Knapmeyer, M., Li, J., Lognonné, P., Maguire, Ross, Panning, M. P., Plesa, A. C., Schimmel, M., Schmerr, N. C., Stählerc, S. C., Stutzmann, E., Xu, Z., Irving, J. C. E., Lekic, V., Durán, C., Drilleau, M., Kim, D., Rivoldini, A., Khan, A., Samuel, H., Antonangeli, D., Bruce Banerdt, W., Beghein, C., Bozdagk, E., Ceylan, S., Charalambous, C., Clinton, J., Davis, P., Garcia, R., Giardini, D., Catherine Horleston, A., Huang, Q., Hurst, K. J., Kawamura, T., King, Scott D., Knapmeyer, M., Li, J., Lognonné, P., Maguire, Ross, Panning, M. P., Plesa, A. C., Schimmel, M., Schmerr, N. C., Stählerc, S. C., Stutzmann, E., and Xu, Z.

Abstract

We present the first observations of seismic waves propagating through the core of Mars. These observations, made using seismic data collected by the InSight geophysical mission, have allowed us to construct the first seismically constrained models for the elastic properties of Mars core. We observe core-Transiting seismic phase SKS from two farside seismic events detected on Mars and measure the travel times of SKS relative to mantle traversing body waves. SKS travels through the core as a compressional wave, providing information about bulk modulus and density. We perform probabilistic inversions using the core-sensitive relative travel times together with gross geophysical data and travel times from other, more proximal, seismic events to seek the equation of state parameters that best describe the liquid iron-Alloy core. Our inversions provide constraints on the velocities in Mars core and are used to develop the first seismically based estimates of its composition. We show that models informed by our SKS data favor a somewhat smaller (median core radius = 1,780 to 1,810 km) and denser (core density = 6.2 to 6.3 g/cm3) core compared to previous estimates, with a P-wave velocity of 4.9 to 5.0 km/s at the core mantle boundary, with the composition and structure of the mantle as a dominant source of uncertainty. We infer from our models that Mars core contains a median of 20 to 22 wt% light alloying elements when we consider sulfur, oxygen, carbon, and hydrogen. These data can be used to inform models of planetary accretion, composition, and evolution.

Published
2023

12. The Global Seismic Moment Rate of Mars After Event S1222a

Author

Knapmeyer, M., primary, Stähler, S., additional, Plesa, A.‐C., additional, Ceylan, S., additional, Charalambous, C., additional, Clinton, J., additional, Dahmen, N., additional, Durán, C., additional, Horleston, A., additional, Kawamura, T., additional, Kim, D., additional, Li, J., additional, Plasman, M., additional, Zenhäusern, G., additional, Weber, R. C., additional, Giardini, D., additional, Panning, M. P., additional, Lognonné, P., additional, and Banerdt, W. B., additional

Published
2023
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13. The Global Seismic Moment Rate of Mars After Event S1222a

Author

Knapmeyer, M., Stähler, S., Plesa, A.‐C., Ceylan, S., Charalambous, C., Clinton, J., Dahmen, N., Durán, C., Horleston, A., Kawamura, T., Kim, D., Li, J., Plasman, M., Zenhäusern, G., Weber, R. C., Giardini, D., Panning, M. P., Lognonné, P., Banerdt, W. B., 2 Institute of Geophysics ETH Zürich Zürich Switzerland, 1 DLR Institute for Planetary Research Berlin Germany, 3 Department of Electrical and Electronic Engineering Imperial College London London UK, 4 Swiss Seismological Service (SED) ETH Zurich Zürich Switzerland, 5 School of Earth Sciences University of Bristol Bristol UK, 6 Université de Paris Institut de physique du globe de Paris CNRS F‐75005 Paris France, 7 Department of Earth, Planetary, and Space Sciences University of California, Los Angeles Los Angeles CA USA, 8 NASA MSFC Huntsville AL USA, and 9 Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA

Subjects
Geophysics, ddc:523, S1222a, General Earth and Planetary Sciences, Mars, seismic moment rate, Mars InSight Marsquake Seismology Seismic Moment, InSight
Abstract

The seismic activity of a planet can be described by the corner magnitude, events larger than which are extremely unlikely, and the seismic moment rate, the long‐term average of annual seismic moment release. Marsquake S1222a proves large enough to be representative of the global activity of Mars and places observational constraints on the moment rate. The magnitude‐frequency distribution of relevant Marsquakes indicates a $b$‐value of 1.06. The moment rate is likely between $1.55\times {10}^{15}\mathrm{N}\mathrm{m}/\mathrm{a}$ and $1.97\times {10}^{18}\mathrm{N}\mathrm{m}/\mathrm{a}$, with a marginal distribution peaking at $4.9\times {10}^{16}\mathrm{N}\mathrm{m}/\mathrm{a}$. Comparing this with pre‐InSight estimations shows that these tended to overestimate the moment rate, and that 30% or more of the tectonic deformation may occur silently, whereas the seismicity is probably restricted to localized centers rather than spread over the entire planet., Plain Language Summary: The seismic moment rate is a measure for how fast quakes accumulate deformation of the planet's rigid outer layer, the lithosphere. In the past decades, several models for the deformation rate of Mars were developed either from the traces quakes leave on the surface, or from mathematical models of how quickly the planet's interior cools down and shrinks. The large marsquake that occurred on the 4th of May 2022 now allows a statistical estimation of the deformation accumulated on Mars per year, and thus to confront these models with reality. It turns out that, although there is a considerable overlap, the models published prior to InSight tend to overestimate the seismic moment rate, and hence the ongoing deformation on Mars. Possible explanations are that 30% or more of the deformation occurs silently, that is, without causing quakes, or that not the entire planet is seismically active but only specific regions., Key Points: A single large marsquake suffices to constrain the global seismic moment rate. Pre‐InSight estimations tended to overestimate the moment rate. Either a significant part of the ongoing deformation occurs silent, or seismic activity is restricted to some activity centers, or both., Eidgenössische Technische Hochschule Zürich http://dx.doi.org/10.13039/501100003006, National Aeronautics and Space Administration http://dx.doi.org/10.13039/100000104, UK Space Agency http://dx.doi.org/10.13039/100011690, Deutsches Zentrum für Luft‐ und Raumfahrt http://dx.doi.org/10.13039/501100002946, Insight SFI Research Centre for Data Analytics http://dx.doi.org/10.13039/501100021525, http://dx.doi.org/10.18715/SEIS.INSIGHT.XB_2016, http://doi.org/10.17189/1517570

Published
2023

18. PLANET TOPERS: Planets, Tracing the Transfer, Origin, Preservation, and Evolution of their ReservoirS

Author

Dehant, V., Asael, D., Baland, R. M., Baludikay, B. K., Beghin, J., Belza, J., Beuthe, M., Breuer, D., Chernonozhkin, S., Claeys, Ph., Cornet, Y., Cornet, L., Coyette, A., Debaille, V., Delvigne, C., Deproost, M. H., De WInter, N., Duchemin, C., El Atrassi, F., François, C., De Keyser, J., Gillmann, C., Gloesener, E., Goderis, S., Hidaka, Y., Höning, D., Huber, M., Hublet, G., Javaux, E. J., Karatekin, Ö., Kodolanyi, J., Revilla, L. Lobo, Maes, L., Maggiolo, R., Mattielli, N., Maurice, M., McKibbin, S., Morschhauser, A., Neumann, W., Noack, L., Pham, L. B. S., Pittarello, L., Plesa, A. C., Rivoldini, A., Robert, S., Rosenblatt, P., Spohn, T., Storme, J. -Y., Tosi, N., Trinh, A., Valdes, M., Vandaele, A. C., Vanhaecke, F., Van Hoolst, T., Van Roosbroek, N., Wilquet, V., and Yseboodt, M.

Published
2016
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19. Surface waves and crustal structure on Mars

Author

Kim, D., primary, Banerdt, W. B., additional, Ceylan, S., additional, Giardini, D., additional, Lekić, V., additional, Lognonné, P., additional, Beghein, C., additional, Beucler, É., additional, Carrasco, S., additional, Charalambous, C., additional, Clinton, J., additional, Drilleau, M., additional, Durán, C., additional, Golombek, M., additional, Joshi, R., additional, Khan, A., additional, Knapmeyer-Endrun, B., additional, Li, J., additional, Maguire, R., additional, Pike, W. T., additional, Samuel, H., additional, Schimmel, M., additional, Schmerr, N. C., additional, Stähler, S. C., additional, Stutzmann, E., additional, Wieczorek, M., additional, Xu, Z., additional, Batov, A., additional, Bozdag, E., additional, Dahmen, N., additional, Davis, P., additional, Gudkova, T., additional, Horleston, A., additional, Huang, Q., additional, Kawamura, T., additional, King, S. D., additional, McLennan, S. M., additional, Nimmo, F., additional, Plasman, M., additional, Plesa, A. C., additional, Stepanova, I. E., additional, Weidner, E., additional, Zenhäusern, G., additional, Daubar, I. J., additional, Fernando, B., additional, Garcia, R. F., additional, Posiolova, L. V., additional, and Panning, M. P., additional

Published
2022
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20. Tidal Constraints on the Martian Interior

Author

Pou, L., primary, Nimmo, F., additional, Rivoldini, A., additional, Khan, A., additional, Bagheri, A., additional, Gray, T., additional, Samuel, H., additional, Lognonné, P., additional, Plesa, A.‐C., additional, Gudkova, T., additional, and Giardini, D., additional

Published
2022
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21. The Mantle Viscosity Structure of Venus.

Author

Maia, J. S., Wieczorek, M. A., and Plesa, A.‐C.

Subjects
VISCOSITY, CONVECTIVE flow, VENUS (Planet), BAYESIAN field theory, DYNAMIC loads, SEISMIC anisotropy
Abstract

The long‐wavelength gravity and topography of Venus are dominated by mantle convective flows, and are hence sensitive to the planet's viscosity structure and mantle density anomalies. By modeling the dynamic gravity and topography signatures and by making use of a Bayesian inference approach, we investigate the viscosity structure of the Venusian mantle by constraining radial viscosity variations. We performed inversions under a wide range of model assumptions that consistently predicted the existence of a thin low‐viscosity zone in the uppermost mantle. The zone is about 235 km thick and has a viscosity reduction of 5–15 times with respect to the underlying mantle. Drawing a parallel with the Earth, the reduced viscosity could be a result of partial melting as suggested for the origin of the asthenosphere. These results support the interpretation that Venus is a geologically active world predominantly governed by ongoing magmatic processes. Plain Language Summary: On Venus, convective up and downwellings in the mantle are intrinsically linked to density variations in the interior. The manner in which the planet is deformed by these mantle flows depends upon its viscosity, and this in turn affects the gravity and topography signals that were recorded by orbiting spacecraft. We tested a large range of model parameters that describe the mantle viscosity on Venus and retrieved the viscosity structure that is compatible with the observations. Our results indicate the presence of a low viscosity zone beneath the Venusian lithosphere in the uppermost mantle. In this region, the viscosity is one order of magnitude smaller than that of the underlying mantle. Starting at a depth of about 80 km and extending over about 235 km, this low viscosity zone could reflect the presence of partial melting and, similarly to the Earth, an asthenosphere on Venus. The presence of partial melt in the interior of Venus supports recent observations of a volcanically active planet and holds major implications for present‐day magmatic activity. Key Points: The long‐wavelength gravity and topography of Venus are investigated in the spectral domain using a dynamic loading modelBayesian inference constraints on the mantle viscosity structure indicate the existence of a low viscosity zone in the upper mantleThe low viscosity zone is potentially associated with partial melting beneath the lithosphere [ABSTRACT FROM AUTHOR]

Published
2023
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22. Surface waves and crustal structure on Mars

Author

Kim, D., Banerdt, W. B., Ceylan, S., Giardini, D., Lekic, V., Lognonne, P., Beghein, C., Beucler, E., Carrasco, S., Charalambous, C., Clinton, J., Drilleau, M., Duran, C., Golombek, M., Joshi, R., Khan, A., Knapmeyer-Endrun, B., Li, J., Maguire, Ross, Pike, W. T., Samuel, H., Schimmel, M., Schmerr, N. C., Stahler, S. C., Stutzmann, E., Wieczorek, M., Xu, Z., Batov, A., Bozdag, E., Dahmen, N., Davis, P., Gudkova, T., Horleston, A., Huang, Q., Kawamura, T., King, Scott D., McLennan, S. M., Nimmo, F., Plasman, M., Plesa, A. C., Stepanova, I. E., Weidner, E., Zenhausern, G., Daubar, I. J., Fernando, B., Garcia, R. F., Posiolova, L., Panning, M. P., Kim, D., Banerdt, W. B., Ceylan, S., Giardini, D., Lekic, V., Lognonne, P., Beghein, C., Beucler, E., Carrasco, S., Charalambous, C., Clinton, J., Drilleau, M., Duran, C., Golombek, M., Joshi, R., Khan, A., Knapmeyer-Endrun, B., Li, J., Maguire, Ross, Pike, W. T., Samuel, H., Schimmel, M., Schmerr, N. C., Stahler, S. C., Stutzmann, E., Wieczorek, M., Xu, Z., Batov, A., Bozdag, E., Dahmen, N., Davis, P., Gudkova, T., Horleston, A., Huang, Q., Kawamura, T., King, Scott D., McLennan, S. M., Nimmo, F., Plasman, M., Plesa, A. C., Stepanova, I. E., Weidner, E., Zenhausern, G., Daubar, I. J., Fernando, B., Garcia, R. F., Posiolova, L., and Panning, M. P.

Abstract

We detected surface waves from two meteorite impacts on Mars. By measuring group velocity dispersion along the impact-lander path, we obtained a direct constraint on crustal structure away from the InSight lander. The crust north of the equatorial dichotomy had a shear wave velocity of approximately 3.2 kilometers per second in the 5- to 30-kilometer depth range, with little depth variation. This implies a higher crustal density than inferred beneath the lander, suggesting either compositional differences or reduced porosity in the volcanic areas traversed by the surface waves. The lower velocities and the crustal layering observed beneath the landing site down to a 10-kilometer depth are not a global feature. Structural variations revealed by surface waves hold implications for models of the formation and thickness of the martian crust.

Published
2022

23. Surface waves and crustal structure on Mars

Author

ETH Zurich, NASA Astrobiology Institute (US), Agence Nationale de la Recherche (France), UK Space Agency, California Institute of Technology, National Aeronautics and Space Administration (US), Kim, D., Banerdt, W. B., Ceylan, S., Giardini, Domenico, Lekic, Vedran, Lognonné, P., Beghein, C., Beucler, E., Carrasco, Sebastián, Charalambous, C., Clinton, John F., Drilleau, M., Duran, C., Golombek, M. P., Joshi, R., Khan, A., Knapmeyer‐Endrun, Brigitte, Li, J., Maguire, R., Pike, William T., Samuel, H., Schimmel, Martin, Schmerr, Nicholas C., Stähler, S. C., Stutzmann, E., Wieczorek, M., Xu, Z. D., Batov, A., Bozdag, E., Dahmen, N., Davis, P., Gudkova, T., Horleston, A., Huang, Quancheng, Kawamura, T., King, S., McLennan, S M, Nimmo, F., Plasman, M., Plesa, A. C., Stepanova, I. E., Weidner, E., Zenhäusern, Geraldine, Daubar, I., Fernando, B., García, R. F., Posiolova, L. V., Panning, Mark P., ETH Zurich, NASA Astrobiology Institute (US), Agence Nationale de la Recherche (France), UK Space Agency, California Institute of Technology, National Aeronautics and Space Administration (US), Kim, D., Banerdt, W. B., Ceylan, S., Giardini, Domenico, Lekic, Vedran, Lognonné, P., Beghein, C., Beucler, E., Carrasco, Sebastián, Charalambous, C., Clinton, John F., Drilleau, M., Duran, C., Golombek, M. P., Joshi, R., Khan, A., Knapmeyer‐Endrun, Brigitte, Li, J., Maguire, R., Pike, William T., Samuel, H., Schimmel, Martin, Schmerr, Nicholas C., Stähler, S. C., Stutzmann, E., Wieczorek, M., Xu, Z. D., Batov, A., Bozdag, E., Dahmen, N., Davis, P., Gudkova, T., Horleston, A., Huang, Quancheng, Kawamura, T., King, S., McLennan, S M, Nimmo, F., Plasman, M., Plesa, A. C., Stepanova, I. E., Weidner, E., Zenhäusern, Geraldine, Daubar, I., Fernando, B., García, R. F., Posiolova, L. V., and Panning, Mark P.

Abstract

We detected surface waves from two meteorite impacts on Mars. By measuring group velocity dispersion along the impact-lander path, we obtained a direct constraint on crustal structure away from the InSight lander. The crust north of the equatorial dichotomy had a shear wave velocity of approximately 3.2 kilometers per second in the 5- to 30-kilometer depth range, with little depth variation. This implies a higher crustal density than inferred beneath the lander, suggesting either compositional differences or reduced porosity in the volcanic areas traversed by the surface waves. The lower velocities and the crustal layering observed beneath the landing site down to a 10-kilometer depth are not a global feature. Structural variations revealed by surface waves hold implications for models of the formation and thickness of the martian crust.

Published
2022

26. Dramatización y griegometrajes : por una 'experiencia' integrada del griego

Author

Palomar Pérez, Natalia, Plesa, Denis C., Solé, David, and Rion, Lorena

Subjects
Audiovisual, Griego oral, Dramatización, Griegometraje, Didáctica experiencial
Abstract

El abordaje oral de los textos orientado a su dramatización hace que el aprendizaje del griego se convierta en una experiencia. La dinámica de decir en griego lo que dice un personaje encarnándolo e interactuando con compañeros promueve una asimilación consistente y grata. En ese proceso cooperativo cada cual despliega sus aptitudes; el resultado es una obra colectiva que se presenta en público, promoviendo la socialización del griego. Su filmación, que da lugar a los griegometrajes, ha estimulado la creación del GID Cinestèsia, que opta por el audiovisual para la enseñanza del griego.

Published
2021

27. Seismic Velocity Variations in a 3D Martian Mantle: Implications for the InSight Measurements

Author

Plesa, A.‐C., primary, Bozdağ, E., additional, Rivoldini, A., additional, Knapmeyer, M., additional, McLennan, S. M., additional, Padovan, S., additional, Tosi, N., additional, Breuer, D., additional, Peter, D., additional, Stähler, S., additional, Wieczorek, M. A., additional, van Driel, M., additional, Khan, A., additional, and Spohn, T., additional

Published
2021
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28. Earth-like Habitable Environments in the Subsurface of Mars

Author

Tarnas, J.D., primary, Mustard, J.F., additional, Sherwood Lollar, B., additional, Stamenković, V., additional, Cannon, K.M., additional, Lorand, J.-P., additional, Onstott, T.C., additional, Michalski, J.R., additional, Warr, O., additional, Palumbo, A.M., additional, and Plesa, A.-C., additional

Published
2021
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29. Seismic detection of the martian core by InSight

Author

Schimmel, Martin, Stähler, S. C., Savas, Ceylan, Duran, A. C., García, Raphael, Giardini, Domenico, Huang, Quancheng, Khan, A., Kim, Doyeon, Lognonné, P., Maguire, Ross, Marusiak, A. G., Plesa, A. C., Samuel, Henri, Schmerr, Nicholas C., Sollberger, David, Stutzmann, E., Antonangeli, D., Clinton, John F., van Driel, M., Drilleau, M., Gudkova, T., Horleston, Anna, Irving, J., Kawamura, T., Lekic, Vedran, Myhill, Robert, Nimmo, F., Panning, Mark, Rivoldini, A., Schmelzbach, C., Stanley, S., Weber, R., Xu, Zongbo, Zenhäusern, G., Banerdt, W. B., Schimmel, Martin, Stähler, S. C., Savas, Ceylan, Duran, A. C., García, Raphael, Giardini, Domenico, Huang, Quancheng, Khan, A., Kim, Doyeon, Lognonné, P., Maguire, Ross, Marusiak, A. G., Plesa, A. C., Samuel, Henri, Schmerr, Nicholas C., Sollberger, David, Stutzmann, E., Antonangeli, D., Clinton, John F., van Driel, M., Drilleau, M., Gudkova, T., Horleston, Anna, Irving, J., Kawamura, T., Lekic, Vedran, Myhill, Robert, Nimmo, F., Panning, Mark, Rivoldini, A., Schmelzbach, C., Stanley, S., Weber, R., Xu, Zongbo, Zenhäusern, G., and Banerdt, W. B.

Abstract

A plethora of geophysical, geo- chemical, and geodynamical observations indicate that the terrestrial planets have differentiated into silicate crusts and mantles that surround a dense core. The latter consists primarily of Fe and some lighter alloying elements (e.g., S, Si, C, O, and H) [1]¿. The Martian meteorites show evidence of chalcophile element depletion, suggesting that the otherwise Fe-Ni- rich core likely contains a sulfide component, which influences physical state.

Published
2021

30. Seismic Constraints on the Thickness and Structure of the Martian Crust from InSight

Author

California Institute of Technology, Panning, M., Knapmeyer‐Endrun, Brigitte, Bissig, F., Joshi, R., Khan, A., Kim, D., Lekic, Vedran, Tauzin, B., Tharimena, S., Plasman, M., Compaire, N., Garcia, R., Margerin, L., Schimmel, Martin, Stutzmann, E., Schmerr, N., Bozdag, E., Plesa, A. C., Wieczorek, M., Broquet, A., Antonangeli, D., McLennan, Scott M., Samuel, H., Michaut, C., Pan, L., Perrin , C., Smrekar, S., Johnson, C. L., Brinkmann, N., Mittelholz, A., Rivoldini, A., Davis, P., Lognonné, P., Pinot, B, Scholz, J. R., Stähler, S., Knapmeyer, M., van Driel, M., Giardini, Domenico, Banerdt, B., California Institute of Technology, Panning, M., Knapmeyer‐Endrun, Brigitte, Bissig, F., Joshi, R., Khan, A., Kim, D., Lekic, Vedran, Tauzin, B., Tharimena, S., Plasman, M., Compaire, N., Garcia, R., Margerin, L., Schimmel, Martin, Stutzmann, E., Schmerr, N., Bozdag, E., Plesa, A. C., Wieczorek, M., Broquet, A., Antonangeli, D., McLennan, Scott M., Samuel, H., Michaut, C., Pan, L., Perrin , C., Smrekar, S., Johnson, C. L., Brinkmann, N., Mittelholz, A., Rivoldini, A., Davis, P., Lognonné, P., Pinot, B, Scholz, J. R., Stähler, S., Knapmeyer, M., van Driel, M., Giardini, Domenico, and Banerdt, B.

Abstract

NASA¿s InSight mission [1] has for the first time placed a very broad-band seismometer on the surface of Mars. The Seismic Experiment for Interior Structure (SEIS) [2] has been collecting continuous data since early February 2019. The main focus of InSight is to enhance our understanding of the internal structure and dynamics of Mars, which includes the goal to better constrain the crustal thickness of the planet [3]. Knowing the present-day crustal thickness of Mars has important implications for its thermal evolution [4] as well as for the partitioning of silicates and heat-producing elements between the different layers of Mars. Current estimates for the crustal thickness of Mars are based on modeling the relationship between topography and gravity [5,6], but these studies rely on different assumptions, e.g. on the density of the crust and upper mantle, or the bulk silicate composition of the planet and the crust. The resulting values for the average crustal thickness differ by more than 100%, from 30 km to more than 100 km [7]. New independent constraints from InSight will be based on seismically determining the crustal thickness at the landing site. This single firm measurement of crustal thickness at one point on the planet will allow to constrain both the average crustal thickness of Mars as well as thickness variations across the planet when combined with constraints from gravity and topography [8]. Here we describe the determination of the crustal structure and thickness at the InSight landing site based on seismic receiver functions for three marsquakes compared with autocorrelations of InSight data [9].

Published
2021

31. Thickness and structure of the Martian crust from InSight seismic data

Author

California Institute of Technology, Swiss National Science Foundation, European Commission, NASA Astrobiology Institute (US), Canadian Space Agency, European Space Agency, Knapmeyer‐Endrun, Brigitte, Panning, M.P., Bissig, F., Joshi, R., Khan, A., Kim, D., Lekic, Vedran, Tauzin, B., Tharimena, S., Plasman, M., Compaire, N., Garcia, R. F., Margerin, L., Schimmel, Martin, Stutzmann, E., Schmerr, N., Bozdag, E., Plesa, A. C., Wieczorek, M. A., Broquet, A., Antonangeli, D., McLennan, Scott M., Samuel, H., Michaut, C., Pan, L., Smrekar, S. E., Johnson, C.L., Brinkman, N., Mittelholz, A., Rivoldini, A., Davis, P. M., Lognonné, P., Pinot, B, Scholz, J. R., Stahler, Simon, Knapmeyer, M., van Driel, M., Giardini, Domenico, Banerdt, W. B., California Institute of Technology, Swiss National Science Foundation, European Commission, NASA Astrobiology Institute (US), Canadian Space Agency, European Space Agency, Knapmeyer‐Endrun, Brigitte, Panning, M.P., Bissig, F., Joshi, R., Khan, A., Kim, D., Lekic, Vedran, Tauzin, B., Tharimena, S., Plasman, M., Compaire, N., Garcia, R. F., Margerin, L., Schimmel, Martin, Stutzmann, E., Schmerr, N., Bozdag, E., Plesa, A. C., Wieczorek, M. A., Broquet, A., Antonangeli, D., McLennan, Scott M., Samuel, H., Michaut, C., Pan, L., Smrekar, S. E., Johnson, C.L., Brinkman, N., Mittelholz, A., Rivoldini, A., Davis, P. M., Lognonné, P., Pinot, B, Scholz, J. R., Stahler, Simon, Knapmeyer, M., van Driel, M., Giardini, Domenico, and Banerdt, W. B.

Abstract

A planet's crust bears witness to the history of planetary formation and evolution, but for Mars, no absolute measurement of crustal thickness has been available. Here, we determine the structure of the crust beneath the InSight landing site on Mars using both marsquake recordings and the ambient wavefield. By analyzing seismic phases that are reflected and converted at subsurface interfaces, we find that the observations are consistent with models with at least two and possibly three interfaces. If the second interface is the boundary of the crust, the thickness is 20 +/- 5 kilometers, whereas if the third interface is the boundary, the thickness is 39 +/- 8 kilometers. Global maps of gravity and topography allow extrapolation of this point measurement to the whole planet, showing that the average thickness of the martian crust lies between 24 and 72 kilometers. Independent bulk composition and geodynamic constraints show that the thicker model is consistent with the abundances of crustal heat-producing elements observed for the shallow surface, whereas the thinner model requires greater concentration at depth.

Published
2021

32. Seismic detection of the martian core

Author

NASA Jet Propulsion Laboratory, European Commission, Agence Nationale de la Recherche (France), Belgian Science Policy Office, European Space Agency, Ministerio de Ciencia, Innovación y Universidades (España), UK Space Agency, Stahler, S. C., Khan, A., Banerdt, W. B., Lognonné, P., Giardini, Domenico, Ceylan, S., Drilleau, M., Duran, A. C., Garcia, R. F., Huang, Q. C., Kim, D., Lekic, Vedran, Samuel, H., Schimmel, Martin, Schmerr, N., Sollberger, D., Stutzmann, E., Xu, Z. D., Antonangeli, D., Charalambous, C., Davis, P. M., Irving, Jessica C. E., Kawamura, T., Knapmeyer, M., Maguire, R., Marusiak, A. G., Panning, M.P., Perrin , C., Plesa, A. C., Rivoldini, A., Schmelzbach, C., Zenhausern, G., Beucler, E., Clinton, John F., Dahmen, N., van Driel, M., Gudkova, T., Horleston, A., Pike, William T., Plasman, M., Smrekar, S. E., NASA Jet Propulsion Laboratory, European Commission, Agence Nationale de la Recherche (France), Belgian Science Policy Office, European Space Agency, Ministerio de Ciencia, Innovación y Universidades (España), UK Space Agency, Stahler, S. C., Khan, A., Banerdt, W. B., Lognonné, P., Giardini, Domenico, Ceylan, S., Drilleau, M., Duran, A. C., Garcia, R. F., Huang, Q. C., Kim, D., Lekic, Vedran, Samuel, H., Schimmel, Martin, Schmerr, N., Sollberger, D., Stutzmann, E., Xu, Z. D., Antonangeli, D., Charalambous, C., Davis, P. M., Irving, Jessica C. E., Kawamura, T., Knapmeyer, M., Maguire, R., Marusiak, A. G., Panning, M.P., Perrin , C., Plesa, A. C., Rivoldini, A., Schmelzbach, C., Zenhausern, G., Beucler, E., Clinton, John F., Dahmen, N., van Driel, M., Gudkova, T., Horleston, A., Pike, William T., Plasman, M., and Smrekar, S. E.

Abstract

Clues to a planet's geologic history are contained in its interior structure, particularly its core. We detected reflections of seismic waves from the core-mantle boundary of Mars using InSight seismic data and inverted these together with geodetic data to constrain the radius of the liquid metal core to 1830 +/- 40 kilometers. The large core implies a martian mantle mineralogically similar to the terrestrial upper mantle and transition zone but differing from Earth by not having a bridgmanite-dominated lower mantle. We inferred a mean core density of 5.7 to 6.3 grams per cubic centimeter, which requires a substantial complement of light elements dissolved in the iron-nickel core. The seismic core shadow as seen from InSight's location covers half the surface of Mars, including the majority of potentially active regions-e.g., Tharsis-possibly limiting the number of detectable marsquakes.

Published
2021

33. Deep Trek: Mission Concepts for Exploring Subsurface Habitability & Life on Mars — A Window into Subsurface Life in the Solar System

Author

Edwards, Charles, primary, Stamenkovic, Vlada, additional, Boston, Penelope, additional, Lynch, Kennda, additional, Tarnas, Jesse, additional, Sherwood-Lollar, Barbara, additional, Atreya, Sushil, additional, Templeton, Alexis, additional, Freeman, Anthony, additional, Fischer, Woodward, additional, Spohn, Tilman, additional, Webster, Chris, additional, Fairén, Alberto G., additional, Mustard, John (Jack), additional, Mischna, Michael, additional, Onstott, Tullis C., additional, Osburn, Magdalena Rose, additional, Kieft, Thomas, additional, Grimm, Robert E., additional, Brinckerhoff, William B., additional, Johnson, Sarah, additional, Beegle, Luther, additional, Head, James, additional, Haldemann, Albert, additional, Cockell, Charles, additional, Hernlund, John, additional, Wilcox, Brian, additional, Paige, David, additional, Etiope, Giuseppe, additional, Glavin, Daniel, additional, Zorzano, Maria-Paz, additional, Sekine, Yasuhito, additional, Fabien, Stalport, additional, Kirschvink, Joseph, additional, Magnabosco, Cara, additional, Orosei, Roberto, additional, Grott, Matthias, additional, Rummel, John D., additional, Kobayashi, Atsuko, additional, Inagaki, Fumio, additional, Bishop, Janice, additional, Chevrier, Vincent, additional, Bell, Mary Sue, additional, Orcutt, Beth N., additional, McIntosh, Jennifer, additional, Miljkovic, Katarina, additional, Breuer, Doris, additional, Usui, Tomohiro, additional, Zacny, Kris, additional, Heggy, Essam, additional, Rivera-Valentín, Edgard G., additional, Barba, Nathan J., additional, Woolley, Ryan, additional, Warr, Oliver, additional, Malaska, Mike, additional, Blank, Jennifer G., additional, Ruffatto, Donald F., additional, Sapers, Haley M., additional, Matthies, Larry H., additional, Ward, Lewis, additional, Shkolyar, Svetlana, additional, Schmelzbach, Cedric, additional, Gabriel, Travis S. J., additional, Parker, Ceth, additional, Bolivar-Torres, Hermes Hernan, additional, Pál, Bernadett, additional, Schulze-Makuch, Dirk, additional, Celis, Jorge Andres Torres, additional, Kereszturi, Akos, additional, Spry, J. Andy, additional, Uckert, Kyle, additional, Hesse, Marc A., additional, Harris, Rachel, additional, Plesa, A.-C., additional, Hu, Renyu, additional, Agha-mohammadi, Ali-akbar, additional, Wade, Brian D., additional, Chatterjee, Snehamoy, additional, McGarey, Patrick, additional, Graham, Heather Valeah, additional, Suzuki, Shino, additional, Schrenk, Matt, additional, Sherrill, Kristopher, additional, Howe, Scott, additional, Manthena, Raju, additional, Burgin, Mariko, additional, Carpenter, Kalind, additional, Giersch, Louis, additional, Cormarkovic, Velibor, additional, Smith, Nigel, additional, McDonnell, Jeffrey J., additional, Michalski, Joseph, additional, Jha, Devanshu, additional, Cable, Morgan L., additional, Gloesener, Elodie, additional, Paul, Varun, additional, Gault, Stewart, additional, Kedar, Sharon, additional, Marteau, Eloise, additional, Temel, Orkun, additional, Krieger, Seth, additional, and Timoney, Ryan, additional

Published
2021
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37. First Receiver Functions on Mars - Constraints on the Martian Crust from InSight

Author

Knapmeyer‐Endrun, Brigitte, Bissig, F., Compaire, N., Joshi, R., Garcia, R., Khan, A., Kim, D., Lekic, Vedran, Margerine, L., Panning, M., Schimmel, Martin, Schmerr, N., Stutzmann, E., Tauzin, B., Tharimena, S., Bozdag, E., Peter, Daniel B., Plesa, A. C., Lognonné, P., Smrekar, S., and Nanerdt, W. B.

Subjects
Mars
Abstract

2020 SSA Annual Meeting, 27-30 April, Albuquerque, New Mexico, NASA¿s InSight mission has for the first time deployed a very broad-band seismometer, SEIS, on the surface of Mars, which has been collecting data continuously since early February 2019. The main focus of InSight is to enhance our understanding of the internal structure and dynamics of Mars, including better constraints on its crustal thickness. Various models based on topography and gravity observed from the orbit currently differ by more than 100% for the average crustal thickness. Here, we present P-to-S and S-to-P receiver functions, which are available for 4 and 3 marsquakes, respectively, up to now. All of these quakes are located at comparatively small epicentral distances, between 25° and 40°. We observe three consistent phases within the first 10 seconds of the P-to-S receiver functions. The S-to-P receiver functions also show a consistent first phase. Later arrivals are harder to pinpoint, which could be due to the comparatively shallow incidence of the S-waves at the considered distances, which prevents the generation of converted waves. To obtain better constraints on velocity, we also calculated apparent velocity curves from the P-to-S receiver functions, but these provide meaningful results for only one event so far, implying a large uncertainty. Due to difficulties in clearly identifying multiples, the receiver functions can currently be explained by either two crustal layers and a thin (25-30 km) crust or three crustal layers and a thicker (40-45 km) crust at the landing site. This model range already improves the present constraints by providing a new maximum value of less than 70 km instead of more than 100 km for the average crustal thickness. Information from noise autocorrelations as a complementary method, identification of P-reverberations and S-precursors in the event recordings and more extensive modeling, ultimately including 3D-effects, are investigated to tighten the constraints.

Published
2020

38. Seismic constraints on the crustal structure of Mars from InSight receiver functions

Author

Knapmeyer‐Endrun, Brigitte, Bissig, F., Compaire, R., Joshi, R., Garcia, R., Khan, A., Kim, D., Lekic, Vedran, Margerine, L., Panning, M., Schimmel, Martin, Schmerr, N., Stutzmann, E., Tauzin, B., Tharimena, S., Bozdag, E., Peter, Daniel B., Plesa, A. C., Lognonné, P., Smrekar, S., and Banerdt, W. B.

Abstract

51st Lunar and Planetary Science Conference (2020), 16 march, Texas, USA, NASA's InSight mission has for the first time placed a very broad-band seismometer on the surface of Mars. The Seismic Experiment for Inte-rior Structure (SEIS) has been collecting continuous data since early February 2019. The main focus of InSight is to enhance our understanding of the internal structure and dynamics of Mars, which includes the goal to better constrain the crustal thickness of the planet [1]. Knowing the present-day crustal thickness of Mars has important implications for its thermal evo-lution [2] as well as for the partitioning of silicates and heat-producing elements between the different layers of Mars. Current estimates for the crustal thickness of Mars are based on modeling the relationship between topography and gravity [3,4], but these studies rely on different assumptions, e.g. on the density of the crust and upper mantle, or the bulk silicate composition of the planet and the crust. The resulting values for the average crustal thickness differ by more than 100%, from 30 km to more than 100 km [5]. New constraints from InSight will be based on seismically determining the crustal thickness at the landing site. This single firm measurement of crustal thickness at one point on the planet will allow to con-strain both the average crustal thickness of Mars as well as thickness variations across the planet when combined with constraints from gravity and topogra-phy [6]. Here we describe the first constraints on the crustal structure and thickness at the InSight landing site based on seismic receiver functions for four marsquakes [7].

Published
2020

39. HP³ Radiometer Measurements from the Mars Mission InSight

Author

Mueller, N., Grott, M., Piqueux, S., Kopp, Emanuel, Spohn, T., Smrekar, S.E., Knollenberg, J., Hudson, T.L., Krause, C., Plesa, A.-C., Siegler, M.A., Spiga, Aymeric, Forget, F., Millour, E., Morgan, P., Golombek, M., and Banerdt, W.B.

Subjects
Asteroiden und Kometen, Weltrauminstrumente, Planetenphysik, Leitungsbereich PF, Mars, Messung, Oberflächentemperatur, Nutzerzentrum für Weltraumexperimente (MUSC)
Published
2019

40. New seismological constraints on the crustal structure of Mars and the Moon

Author

Knapmeyer‐Endrun, Brigitte, Panning, Mark P., Bissig, F., Joshi, Rakshit, Khan, A., Kim, Doyeon, Lekic, Vedran, Tauzin, Benoit, Tharimena, S., Plasman, Matthieu, Compaire, Nicolas, Garcia, Raphael F., Margerin, Ludovic, Schimmel, Martin, Stutzmann, E., Schmerr, Nicholas C., Antonangeli, D., Bozdag, E., McLennan, S., Peter, Daniel B., Plesa, A. C., Samuel, H., Wieczorek, M., Davis, Paul, Lognonné, P., Pinot, Baptiste, Scholz, J. R., Staehler, Simon C., Knapmeyer, M., Brinkman, N., van Driel, M., Giardini, Domenico, Johnson, C., Smrekar, S. E., Banerdt, William B., Knapmeyer‐Endrun, Brigitte, Panning, Mark P., Bissig, F., Joshi, Rakshit, Khan, A., Kim, Doyeon, Lekic, Vedran, Tauzin, Benoit, Tharimena, S., Plasman, Matthieu, Compaire, Nicolas, Garcia, Raphael F., Margerin, Ludovic, Schimmel, Martin, Stutzmann, E., Schmerr, Nicholas C., Antonangeli, D., Bozdag, E., McLennan, S., Peter, Daniel B., Plesa, A. C., Samuel, H., Wieczorek, M., Davis, Paul, Lognonné, P., Pinot, Baptiste, Scholz, J. R., Staehler, Simon C., Knapmeyer, M., Brinkman, N., van Driel, M., Giardini, Domenico, Johnson, C., Smrekar, S. E., and Banerdt, William B.

Abstract

Planetary crusts are the results of mantle differentiation, so their thickness provides important constraints on the thermochemical evolution of a planet, including its heat budget and mantle rheology. Information on crustal layering and seismic velocities can also provide important constraints on porosity and geochemistry of the crust. Here, we use data from the InSight mission, which landed in November 2018, to provide seismological constraints on the crustal layering and thickness of Mars for the first time. Results are mainly based on Ps-receiver functions from three events with magnitudes between 3.1 and 3.6 at distances between 27.5° and 47° (±10°) from the lander, originating in the Cerberus Fossae region, the only events, so far, with clear, impulsive P-wave onsets and known epicenter. Ps-receiver functions use converted phases in the P-wave coda to derive information on discontinuities beneath the seismometer. Due to the limited number of events and the small epicentral distance range covered, inversions of the data are still ambiguous. Two sets of models can explain the waveforms, one consisting of a two-layer crust of about 20 to 23 km thickness, the other having a three-layer crust of about 40 to 45 km thickness. By excluding crustal thicknesses in excess of 45 km at the landing site, we can constrain the global average crustal thickness of Mars to be less than 70 km. Both model types also agree with S-receiver functions for two events and seismic P-waves reflected in the crust and extracted from autocorrelations using the coda of different types of marsquakes as well as the background wavefield. Furthermore, the results are compatible with independently conducted moment tensor inversions for a limited number of events as well as modeling of the wave-propagation of high-frequency events. We find low seismic P-wave velocities below 3.4 km/s within the upper approximately 10 km, likely indicating a high porosity. For the Moon, we present Sp-receiver functi

Published
2020

41. Constraints on the shallow elastic and anelastic structure of Mars from InSight seismic data

Author

Centre National D'Etudes Spatiales (France), California Institute of Technology, NASA Astrobiology Institute (US), Swiss National Science Foundation, European Commission, Schimmel, Martin [0000-0003-2601-4462], Lognonné, P., Banerdt, W. B., Pike, William T., Giardini, Domenico, Christensen, U., Garcia, R. F., Kawamura, T., Kedar, S., Knapmeyer‐Endrun, Brigitte, Margerin, L., Nimmo, F., Daubar, I., Delage, P., Fuji, N., Golombek, M., Grott, M., Horleston, A., Hurst, K., Irving, J., Jacob, A., Knollenberg, J., Krasner, S., Krause, C., Lorenz, R., Michaut, C., Myhill, Robert, Nissen-Meyer, T., ten Pierick, J., Plesa, A. C., Quantin-Nataf, C., Robertsson, J., Rochas, L., Schimmel, Martin, Smrekar, S., Spohn, T., Teanby, N., Tromp, J., Vallade, J., Verdier, N., Vrettos, C., Weber, R., Banfield, D., Barrett, E., Bierwirth, M., Calcutt, S., Compaire, N., Johnson, C. L., Mance, D., Euchner, F., Kerjean, L., Mainsant, G., Mocquet, A., Rodriguez Manfredi, J. A., Pont, G., Laudet, P., Nebut, T., de Raucourt, S., Robert, O., Russell, C. T., Sylvestre-Baron, A., Tillier, S., Warren, T., Wieczorek, M., Yana, C., Zweifel, P., Panning, M., Tauzin, B., Scholz, J. R., Antonangeli, D., Barkaoui, S., Beucler, E., Bissig, F., Brinkman, N., Calvet, M., Ceylan, S., Charalambous, C., Davis, P., van Driel, M., Drilleau, M., Fayon, L., Joshi, R., Kenda, B., Khan, A., Knapmeyer, M., Lekic, Vedran, McClean, J., Mimoun, D., Murdoch, N., Pan, L., Perrin , C., Pinot, B, Pou, L., Menina, S., Rodríguez, S., Schmelzbach, C., Schmerr, N., Sollberger, D., Spiga, A., Stähler, S., Stott, A., Stutzmann, E., Tharimena, S., Widmer-Schnidrig, R., Andersson, F., Ansan, V., Beghein, C., Böse, M., Bozdag, E., Clinton, John F., Centre National D'Etudes Spatiales (France), California Institute of Technology, NASA Astrobiology Institute (US), Swiss National Science Foundation, European Commission, Schimmel, Martin [0000-0003-2601-4462], Lognonné, P., Banerdt, W. B., Pike, William T., Giardini, Domenico, Christensen, U., Garcia, R. F., Kawamura, T., Kedar, S., Knapmeyer‐Endrun, Brigitte, Margerin, L., Nimmo, F., Daubar, I., Delage, P., Fuji, N., Golombek, M., Grott, M., Horleston, A., Hurst, K., Irving, J., Jacob, A., Knollenberg, J., Krasner, S., Krause, C., Lorenz, R., Michaut, C., Myhill, Robert, Nissen-Meyer, T., ten Pierick, J., Plesa, A. C., Quantin-Nataf, C., Robertsson, J., Rochas, L., Schimmel, Martin, Smrekar, S., Spohn, T., Teanby, N., Tromp, J., Vallade, J., Verdier, N., Vrettos, C., Weber, R., Banfield, D., Barrett, E., Bierwirth, M., Calcutt, S., Compaire, N., Johnson, C. L., Mance, D., Euchner, F., Kerjean, L., Mainsant, G., Mocquet, A., Rodriguez Manfredi, J. A., Pont, G., Laudet, P., Nebut, T., de Raucourt, S., Robert, O., Russell, C. T., Sylvestre-Baron, A., Tillier, S., Warren, T., Wieczorek, M., Yana, C., Zweifel, P., Panning, M., Tauzin, B., Scholz, J. R., Antonangeli, D., Barkaoui, S., Beucler, E., Bissig, F., Brinkman, N., Calvet, M., Ceylan, S., Charalambous, C., Davis, P., van Driel, M., Drilleau, M., Fayon, L., Joshi, R., Kenda, B., Khan, A., Knapmeyer, M., Lekic, Vedran, McClean, J., Mimoun, D., Murdoch, N., Pan, L., Perrin , C., Pinot, B, Pou, L., Menina, S., Rodríguez, S., Schmelzbach, C., Schmerr, N., Sollberger, D., Spiga, A., Stähler, S., Stott, A., Stutzmann, E., Tharimena, S., Widmer-Schnidrig, R., Andersson, F., Ansan, V., Beghein, C., Böse, M., Bozdag, E., and Clinton, John F.

Abstract

Mars’s seismic activity and noise have been monitored since January 2019 by the seismometer of the InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) lander. At night, Mars is extremely quiet; seismic noise is about 500 times lower than Earth’s microseismic noise at periods between 4 s and 30 s. The recorded seismic noise increases during the day due to ground deformations induced by convective atmospheric vortices and ground-transferred wind-generated lander noise. Here we constrain properties of the crust beneath InSight, using signals from atmospheric vortices and from the hammering of InSight’s Heat Flow and Physical Properties (HP3) instrument, as well as the three largest Marsquakes detected as of September 2019. From receiver function analysis, we infer that the uppermost 8–11 km of the crust is highly altered and/or fractured. We measure the crustal diffusivity and intrinsic attenuation using multiscattering analysis and find that seismic attenuation is about three times larger than on the Moon, which suggests that the crust contains small amounts of volatiles.

Published
2020

44. The heat flow and physical properties package HP3 for the InSight mission

Author

Spohn, Tilman, Grott, Matthias, Smrekar, S.E., Knollenberg, J., Hudson, T.L., Krause, Christian, Müller, Nils, Jänchen, Judit, Börner, Anko, Wippermann, Torben, Krömer, Olaf, Lichtenheldt., Roy, Wiśniewski, Lukasz, Grygorczuk, Jurek, Fittock, Mark, Rheershemius, Sibo, Spröwitz, Tom, Kopp, Emanuel, Walter, Ingo, Plesa, A.-C, Breuer, Doris, Morgan, P., Banerdt, W.B., Russel, Chris, and Banerdt, W.B.

Subjects
Asteroiden und Kometen, Echtzeit-Datenprozessierung, Raumfahrt-Systemdynamik, Weltrauminstrumente, InSight Mission, Leitungsbereich PF, Mars, Temperatur im Mars, Nutzerzentrum für Weltraumexperimente (MUSC), Physikalische Eigenschaften des Marsbodens, Planetenphysik, Wärmeflussmessung, Land und Explorationstechnologie, Mechanik und Thermalsysteme
Abstract

The Heat Flow and Physical Properties Package HP3 for the InSight mission will attempt the first measurement of the planetary heat flow of Mars. The data will be taken at the InSight landing site in Elysium planitia (136 ◦E, 5 ◦N) and the uncertainty of the mea- surement aimed for shall be better than ±5 mW m−2 . The package consists of a mechanical hammering device called the “Mole” for penetrating into the regolith, an instrumented tether which the Mole pulls into the ground, a fixed radiometer to determine the surface brightness temperature and an electronic box. The Mole and the tether are housed in a support struc- ture before being deployed. The tether is equipped with 14 platinum resistance temperature sensors to measure temperature differences with a 1-σ uncertainty of 6.5 mK. Depth is de- termined by a tether length measurement device that monitors the amount of tether extracted from the support structure and a tiltmeter that measures the angle of the Mole axis to the local gravity vector. The Mole includes temperature sensors and heaters to measure the re- golith thermal conductivity to better than 3.5% (1-σ ) using the Mole as a modified line heat source. The Mole is planned to advance at least 3 m—sufficiently deep to reduce errors from daily surface temperature forcings—and up to 5 m into the martian regolith. After landing, HP3 will be deployed onto the martian surface by a robotic arm after choosing an instru- ment placement site that minimizes disturbances from shadows caused by the lander and the seismometer. The Mole will then execute hammering cycles, advancing 50 cm into the sub- surface at a time, followed by a cooldown period of at least 48 h to allow heat built up during hammering to dissipate. After an equilibrated thermal state has been reached, a thermal con- ductivity measurement is executed for 24 h. This cycle is repeated until the final depth of 5 m is reached or further progress becomes impossible. The subsequent monitoring phase consists of hourly temperature measurements and lasts until the end of the mission. Model calculations show that the duration of temperature measurement required to sufficiently re- duce the error introduced by annual surface temperature forcings is 0.6 martian years for a final depth of 3 m and 0.1 martian years for the target depth of 5 m.

Published
2018

45. Onset of solid-state mantle convection and mixing during magma ocean solidification

Author

Maurice, M., Tosi, Nicola, Samuel, H., Plesa, A.-C., Hüttig, C., Breuer, D., Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)

Subjects
Magma ocean, Planetenphysik, Mixing, [SDU]Sciences of the Universe [physics], Fractional crystallization, Mantle convection, ddc:550, Mars, mantle mixing, Terrestrial planets
Abstract

Energy sources involved in the early stages of planetary formation can cause partial or even complete melting of the mantle of terrestrial bodies leading to the formation of magma oceans. Upon planetary cooling, solidification is expected to take place from the bottom upwards because of the steeper slope of the liquid adiabat with respect to the liquidus (Elkins-Tanton, 2012; Solomatov, 2015). Fractional solidification, in particular, can lead to the formation of a compositional layering that can play a fundamental role for the subsequent long-term dynamics and evolution of the interior (Tosi et al., 2013; Plesa et al., 2014). In order to assess to what extent primordial compositional heterogeneities generated upon magma ocean solidification can be preserved, we investigate the cooling and solidification of a whole-mantle magma ocean along with the conditions that allow solid-state convection to start mixing the mantle before solidification has completed. To this end, we run 2-D numerical simulations in cylindrical geometry using the finite-volume code GAIA (Hüttig et al., 2013). We treat the liquid magma ocean in a parametrized fashion while we self-consistently solve the conservation equations of thermochemical convection in the growing solid mantle accounting for pressure-, temperature- and melt-dependent rheology. We consider two end-member cases: fractional crystallization, where melt is instantaneously extracted into the overlying liquid leaving beneath a differentiated mantle, and batch crystallization where melt remains in contact with the silicate matrix throughout solidification causing no differentiation. By testing the effects of different cooling rates and Rayleigh numbers, we show that for a lifetime of the liquid magma ocean between 1 and 10 Myr (Lebrun et al., 2013), the onset of solid state convection prior to complete mantle crystallization is possible and that part or even all of the compositional heterogeneities generated upon fractionation can be erased by efficient mantle stirring (Figure 1). We discuss the consequences of our findings in relation to the early and long-term evolution of compositional heterogeneities generated via fractional crystallization of magma oceans in terrestrial bodies with emphasis on Mars' thermochemical history.

Published
2017
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47. The Thermal State and Interior Structure of Mars

Author

Plesa, A.‐C., primary, Padovan, S., additional, Tosi, N., additional, Breuer, D., additional, Grott, M., additional, Wieczorek, M. A., additional, Spohn, T., additional, Smrekar, S. E., additional, and Banerdt, W. B., additional

Published
2018
Full Text
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