Search

Your search keyword '"William Bruce Banerdt"' showing total 15 results
Start Over Author "William Bruce Banerdt" Search Limiters Full Text
15 results on '"William Bruce Banerdt"'

1. Evaluation of S1222a Source Parameters Based on Site Effect Simulation and Implication for the Event Origin

Author

Wanbo Xiao, Taichi Kawamura, Zongbo Xu, Sebastián Carrasco, Keisuke Onodera, Grégory Sainton, Philippe Lognonné, Yanbin Wang, Brigitte Knapmeyer‐Endrun, and William Bruce Banerdt

Subjects
InSight, martian seismology, marsquakes, corner frequency, site effect, S1222a, Geophysics. Cosmic physics, QC801-809
Abstract

Abstract Estimating the rupture process of a quake constrains the tectonic setting of its source region. In terrestrial seismology, the rupture process can be described with a classical ω2 model. In this study, we focus on one key source parameter of S1222a, the corner frequency, to investigate its origin. However, estimating the corner frequency of S1222a is complicated by S1222a's non‐classical spectra which deviate from the ω2 model. To explain S1222a's spectra, we take into account the site effect at the InSight landing site. Through numerical simulation, we demonstrate that the spectral fitting is greatly improved after considering the site effect. We further estimated the source spectrum and stress drop of S1222a. The obtained stress drop resembles the values for regional tectonic earthquakes and shallow moonquakes but differs from the Cerberus Fossae marsquakes, which favors a different tectonic origin from the Cerberus Fossae marsquakes for S1222a.

Published
2023
Full Text
View/download PDF

2. Seismic Scattering and Absorption Properties of Mars Estimated Through Coda Analysis on a Long‐Period Surface Wave of S1222a Marsquake

Author

Keisuke Onodera, Takuto Maeda, Kiwamu Nishida, Taichi Kawamura, Ludovic Margerin, Sabrina Menina, Philippe Lognonné, and William Bruce Banerdt

Subjects
planetary seismology, marsquake, seismic scattering, surface wave, Mars, comparative planetology, Geophysics. Cosmic physics, QC801-809
Abstract

Abstract On 4 May 2022, the seismometer on Mars observed the largest marsquake (S1222a) during its operation. One of the most specific features of S1222a is the long event duration lasting more than 8 hr, in addition to the clear appearance of body and surface waves. As demonstrated on Earth, by modeling a long‐lasting and scattered surface wave with the radiative transfer theory under the isotropic scattering condition, we estimated the scattering and intrinsic quality factors of Mars (Qs and Qi). This study especially focused on the frequency range between 0.05–0.09 Hz, where Qs and Qi have not been constrained yet. Our results revealed that Qi = 1,000–1,500 and Qs = 30–500. By summarizing the Martian Qi and Qs estimated so far and by comparing them with those of other celestial bodies, we found that, overall, the Martian scattering and absorption properties showed Earth‐like values.

Published
2023
Full Text
View/download PDF

3. Investigation of Martian Regional Crustal Structure Near the Dichotomy Using S1222a Surface‐Wave Group Velocities

Author

Zongbo Xu, Adrien Broquet, Nobuaki Fuji, Taichi Kawamura, Philippe Lognonné, Jean‐Paul Montagner, Lu Pan, Martin Schimmel, Eléonore Stutzmann, and William Bruce Banerdt

Subjects
Martian seismology, crustal structure, surface waves, Martian dichotomy, Geophysics. Cosmic physics, QC801-809
Abstract

Abstract Knowledge of Martian crust and uppermost mantle aid us studying the planet's evolution. NASA's InSight mission provides seismic data being used to reveal the interior structure. Most studies have focused on the crustal structure beneath InSight lander, but the seismic structure of other regions has remained poorly known. We use surface‐wave data to investigate the crustal structure of a large region along the Medusa Fossae Formation and the dichotomy. We adopt the largest‐magnitude marsquake (S1222a) that has been recorded, which provides both Rayleigh‐ and Love‐wave signals. We measure and jointly invert these surface‐wave fundamental‐mode group velocities from ∼15 to 40 s to estimate the average 1D isotropic velocity models. These models includes a high‐velocity layer at ∼7‐km depth, which could be due to a regional basaltic activity or regional stress. Our models also indicate that a common intra‐crustal structure (∼12–40 km depth) may exist in this region along the dichotomy.

Published
2023
Full Text
View/download PDF

4. Crustal Structure Constraints From the Detection of the SsPp Phase on Mars

Author

Jiaqi Li, Caroline Beghein, Paul Davis, Mark. A. Wieczorek, Scott M. McLennan, Doyeon Kim, Ved Lekić, Matthew Golombek, Martin Schimmel, Eleonore Stutzmann, Philippe Lognonné, and William Bruce Banerdt

Subjects
Martian crust, porosity, marsquake, P‐wave speed, Astronomy, QB1-991, Geology, QE1-996.5
Abstract

Abstract The shallowest intracrustal layer (extending to 8 ± 2 km depth) beneath the Mars InSight Lander site exhibits low seismic wave velocity, which is likely related to a combination of high porosity and other lithological factors. The SsPp phase, an SV‐ to P‐wave reflection on the receiver side, is naturally suited for constraining the seismic structure of this top crustal layer since its prominent signal makes it observable with a single station without the need for stacking. We have analyzed six broadband and low‐frequency seismic events recorded on Mars and made the first coherent detection of the SsPp phase on the red planet. The timing and amplitude of SsPp confirm the existence of the ∼8 km interface in the crust and the large wave speed (or impedance) contrast across it. With our new constraints from the SsPp phase, we determined that the average P‐wave speed in the top crustal layer is between 2.5 and 3.2 km/s, which is a more precise and robust estimate than the previous range of 2.0–3.5 km/s obtained by receiver function analysis. The low velocity of Layer 1 likely results from the presence of relatively low‐density lithified sedimentary rocks and/or aqueously altered igneous rocks that also have a significant amount of porosity, possibly as much as 22%–30% by volume (assuming an aspect ratio of 0.1 for the pore space). These porosities and average P‐wave speeds are compatible with our current understanding of the upper crustal stratigraphy beneath the InSight Lander site.

Published
2023
Full Text
View/download PDF

5. Empirical H/V spectral ratios at the InSight landing site and implications for the martian subsurface structure

Author

Sebastián Carrasco, Brigitte Knapmeyer-Endrun, Ludovic Margerin, Cédric Schmelzbach, Keisuke Onodera, Lu Pan, Philippe Lognonné, Sabrina Menina, Domenico Giardini, Eléonore Stutzmann, John Clinton, Simon Stähler, Martin Schimmel, Matthew Golombek, Manuel Hobiger, Miroslav Hallo, Sharon Kedar, William Bruce Banerdt, University of Cologne, 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), 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), Institute of Geophysics [ETH Zürich], Department of Earth Sciences [Swiss Federal Institute of Technology - ETH Zürich] (D-ERDW), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Graduate University for Advanced Studies [Hayama] (SOKENDAI), University of Copenhagen = Københavns Universitet (UCPH), Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Swiss Seismological Service [ETH Zurich] (SED), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)-Department of Earth Sciences [Swiss Federal Institute of Technology - ETH Zürich] (D-ERDW), and ANR-19-CE31-0008,MAGIS,MArs Geophysical InSight(2019)

Subjects
Geophysics, Seismic noise, Coda waves, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Geochemistry and Petrology, Site effects, Martian seismology, Marsquakes
Abstract

SUMMARY The horizontal-to-vertical (H/V) spectral ratio inversion is a traditional technique for deriving the local subsurface structure on Earth. We calculated the H/V from the ambient vibrations at different wind levels at the InSight landing site, on Mars, and also computed the H/V from the S-wave coda of the martian seismic events (marsquakes). Different H/V curves were obtained for different wind periods and from the marsquakes. From the ambient vibrations, the recordings during low-wind periods are close to the instrument self-noise level. During high-wind periods, the seismic recordings are highly contaminated by the interaction of the lander with the wind and the martian ground. Therefore, these recordings are less favourable for traditional H/V analysis. Instead, the recordings of the S-wave coda of marsquakes were preferred to derive the characteristic H/V curve of this site between 0.4 and 10 Hz. The final H/V curve presents a characteristic trough at 2.4 Hz and a strong peak at 8 Hz. Using a full diffuse wavefield approach as the forward computation and the Neighbourhood Algorithm as the sampling technique, we invert for the 1-D shear wave velocity structure at the InSight landing site. Based on our inversion results, we propose a strong site effect at the InSight site to be due to the presence of a shallow high-velocity layer (SHVL) over low-velocity units. The SHVL is likely placed below a layer of coarse blocky ejecta and can be associated with Early Amazonian basaltic lava flows. The units below the SHVL have lower velocities, possibly related to a Late Hesperian or Early Amazonian epoch with a different magmatic regime and/or a greater impact rate and more extensive weathering. An extremely weak buried low velocity layer (bLVL) between these lava flows explains the data around the 2.4 Hz trough, whereas a more competent bLVL would not generate this latter feature. These subsurface models are in good agreement with results from hammering experiment and compliance measurements at the InSight landing site. Finally, this site effect is revealed only by seismic events data and explains the larger horizontal than vertical ground motion recorded for certain type of marsquakes.

Published
2022

6. Seasonal Variations of Soil Thermal Conductivity at the InSight Landing Site

Author

Matthias Grott, Sylvain Piqueux, Tilman Spohn, Joerg Knollenberg, Christian Krause, Eloise Marteau, Troy L. Hudson, Francois Forget, Lucas Lange, N. Müller, Matthew P. Golombek, Seiichi Nagihara, Paul Morgan, J.P. Murphy, Matthew Adam Siegler, Scott D. King, Donald Banfield, Suzanne E Smrekar, and William Bruce Banerdt

Subjects
Geophysics, InSight Mars Regolith Thermal Conductivity, General Earth and Planetary Sciences, InSight HP3 thermal conductivity soil heat transport
Abstract

The heat flow and physical properties package measured soil thermal conductivity at the landing site in the 0.03 to 0.37 m depth range. Six measurements spanning solar longitudes from 8.0$^\circ$ to 210.0$^\circ$ were made and atmospheric pressure at the site was simultaneously measured using InSight’s Pressure Sensor. We find that soil thermal conductivity strongly correlates with atmospheric pressure. This trend is compatible with predictions of the pressure dependence of thermal conductivity for unconsolidated soils under martian atmospheric conditions, indicating that heat transport through the pore filling gas is a major contributor to the total heat transport. This implies that any cementation or induration of the soil sampled by the experiments must be minimal and that the soil surrounding the mole at depths below the duricrust is unconsolidated. Thermal conductivity data presented here are the first direct evidence that the atmosphere interacts with the top most meter of material on Mars.

Published
2023

7. First observations of core-transiting seismic phases on Mars

Author

Jessica C. E. Irving, Vedran Lekić, Cecilia Durán, Mélanie Drilleau, Doyeon Kim, Attilio Rivoldini, Amir Khan, Henri Samuel, Daniele Antonangeli, William Bruce Banerdt, Caroline Beghein, Ebru Bozdağ, Savas Ceylan, Constantinos Charalambous, John Clinton, Paul Davis, Raphaël Garcia, null Domenico Giardini, Anna Catherine Horleston, Quancheng Huang, Kenneth J. Hurst, Taichi Kawamura, Scott D. King, Martin Knapmeyer, Jiaqi Li, Philippe Lognonné, Ross Maguire, Mark P. Panning, Ana-Catalina Plesa, Martin Schimmel, Nicholas C. Schmerr, Simon C. Stähler, Eleonore Stutzmann, Zongbo Xu, University of Bristol, School of Earth Sciences, Department of Geology, University of Maryland, Institute of Geophysics [ETH Zürich], Department of Earth Sciences [Swiss Federal Institute of Technology - ETH Zürich] (D-ERDW), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Royal Observatory of Belgium [Brussels] (ROB), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Department of Earth, Planetary, and Space Sciences, University of California Los Angeles, Department of Applied Mathematics and Statistics & Department of Geophysics, Colorado School of Mines, Department of Electrical and Electronic Engineering, Imperial College London, South Kensington Campus, London, United Kingdom, Swiss Seismological Service [ETH Zurich] (SED), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)-Department of Earth Sciences [Swiss Federal Institute of Technology - ETH Zürich] (D-ERDW), School of Earth Sciences [Bristol], University of Bristol [Bristol], Department of Applied Mathematics and Statistics & Department of Geophysics, Colorado School of Mines, Golden, CO, USA, Department of Geosciences, Virginia Tech, Blacksburg, VA, DLR-Berlin, Institute of Planetary Research, Germany, Department of Geology, University of Illinois Urbana-Champaign, Urbana, IL, USA, Geosciences Barcelona - CSIC, Barcelona, Spain, Department of Geology, University of Maryland, College Park, USA, S-CAPAD/DANTE, MAGIS, ANR-19-CE31-0008-08, and ANR-18-IDEX-0001

Subjects
Core evolution, Mars, Planetary structure, Multidisciplinary, marsquake, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], planetary structure, Impact, [SDU]Sciences of the Universe [physics], Mars InSight Seismology SKS Core, core evolution, Core, Seismology
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., Proceedings of the National Academy of Sciences of the United States of America, 120 (18), ISSN:0027-8424, ISSN:1091-6490

Published
2023
Full Text
View/download PDF

8. Modeling Seismic Recordings of High‐Frequency Guided Infrasound on Mars

Author

Zongbo Xu, Marouchka Froment, Raphaël F. Garcia, Éric Beucler, Keisuke Onodera, Taichi Kawamura, Philippe Lognonné, and William Bruce Banerdt

Subjects
Geophysics, Space and Planetary Science, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous)
Published
2022

9. Crustal Structure Constraints from the Detection of the SsPp Phase on Mars

Author

Jiaqi Li, Caroline Beghein, Paul Davis, Mark. A. Wieczorek, Scott M. McLennan, Doyeon Kim, Ved Lekić, Matthew Golombek, Martin Schimmel, Eleonore Stutzmann, Philippe Lognonné, and William Bruce Banerdt

Subjects
porosity, marsquake, Martian crust, General Earth and Planetary Sciences, P-wave speed, Environmental Science (miscellaneous)
Abstract

The shallowest intracrustal layer (extending to 8 +/- 2 km depth) beneath the Mars InSight Lander site exhibits low seismic wave velocity, which is likely related to a combination of high porosity and other lithological factors. The SsPp phase, an SV- to P-wave reflection on the receiver side, is naturally suited for constraining the seismic structure of this top crustal layer since its prominent signal makes it observable with a single station without the need for stacking. We have analyzed six broadband and low-frequency seismic events recorded on Mars and made the first coherent detection of the SsPp phase on the red planet. The timing and amplitude of SsPp confirm the existence of the similar to 8 km interface in the crust and the large wave speed (or impedance) contrast across it. With our new constraints from the SsPp phase, we determined that the average P-wave speed in the top crustal layer is between 2.5 and 3.2 km/s, which is a more precise and robust estimate than the previous range of 2.0-3.5 km/s obtained by receiver function analysis. The low velocity of Layer 1 likely results from the presence of relatively low-density lithified sedimentary rocks and/or aqueously altered igneous rocks that also have a significant amount of porosity, possibly as much as 22%-30% by volume (assuming an aspect ratio of 0.1 for the pore space). These porosities and average P-wave speeds are compatible with our current understanding of the upper crustal stratigraphy beneath the InSight Lander site., Earth and Space Science, 10 (3), ISSN:2333-5084

Published
2022

10. Newly formed craters on Mars located using seismic and acoustic wave data from InSight

Author

Raphael F. Garcia, Ingrid J. Daubar, Éric Beucler, Liliya V. Posiolova, Gareth S. Collins, Philippe Lognonné, Lucie Rolland, Zongbo Xu, Natalia Wójcicka, Aymeric Spiga, Benjamin Fernando, Gunnar Speth, Léo Martire, Andrea Rajšić, Katarina Miljković, Eleanor K. Sansom, Constantinos Charalambous, Savas Ceylan, Sabrina Menina, Ludovic Margerin, Rémi Lapeyre, Tanja Neidhart, Nicholas A. Teanby, Nicholas C. Schmerr, Mickaël Bonnin, Marouchka Froment, John F. Clinton, Ozgur Karatekin, Simon C. Stähler, Nikolaj L. Dahmen, Cecilia Durán, Anna Horleston, Taichi Kawamura, Matthieu Plasman, Géraldine Zenhäusern, Domenico Giardini, Mark Panning, Mike Malin, William Bruce Banerdt, Science and Technology Facilities Council (STFC), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Department of Earth, Environmental and Planetary Sciences [Providence], Brown University, Laboratoire de Planétologie et Géosciences [UMR_C 6112] (LPG), Université d'Angers (UA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Malin Space Science Systems (MSSS), Department of Earth Science and Engineering [Imperial College London], Imperial College London, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Géoazur (GEOAZUR 7329), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Department of Earth Sciences [Oxford], University of Oxford, Curtin University [Perth], Planning and Transport Research Centre (PATREC), UAR-Institut de physique du globe de Paris (IPGP-UAR / UAR3454), Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Department of Electrical and Electronic Engineering [London] (DEEE), 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), 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), Centre National d'Études Spatiales [Toulouse] (CNES), School of Earth Sciences [Bristol], University of Bristol [Bristol], University of Maryland [College Park], University of Maryland System, Earth and Environmental Sciences Division [Los Alamos], Los Alamos National Laboratory (LANL), Royal Observatory of Belgium [Brussels] (ROB), Institute of Geophysics [ETH Zürich], Department of Earth Sciences [Swiss Federal Institute of Technology - ETH Zürich] (D-ERDW), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Institut für Geophysik [Zürich], California Institute of Technology (CALTECH), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), ANR-14-CE36-0012,SEISMARS,Seismology on Mars(2014), ANR-19-CE31-0008,MAGIS,MArs Geophysical InSight(2019), and ANR-18-IDEX-0001,Université de Paris,Université de Paris(2018)

Subjects
Science & Technology, EXPLOSION, Natural hazards, Geology, ATMOSPHERE, [SDU]Sciences of the Universe [physics], Inner planets, Meteoritics, Physical Sciences, General Earth and Planetary Sciences, Meteorology & Atmospheric Sciences, Geosciences, Multidisciplinary, MOON, Seismology, METEORITE IMPACTS
Abstract

International audience; Meteoroid impacts shape planetary surfaces by forming new craters and alter atmospheric composition. During atmospheric entry and impact on the ground, meteoroids excite transient acoustic and seismic waves. However, new crater formation and the associated impact-induced mechanical waves have yet to be observed jointly beyond Earth. Here we report observations of seismic and acoustic waves from the NASA InSight lander’s seismometer that we link to four meteoroid impact events on Mars observed in spacecraft imagery. We analysed arrival times and polarization of seismic and acoustic waves to estimate impact locations, which were subsequently confirmed by orbital imaging of the associated craters. Crater dimensions and estimates of meteoroid trajectories are consistent with waveform modelling of the recorded seismograms. With identified seismic sources, the seismic waves can be used to constrain the structure of the Martian interior, corroborating previous crustal structure models, and constrain scaling relationships between the distance and amplitude of impact-generated seismic waves on Mars, supporting a link between the seismic moment of impacts and the vertical impactor momentum. Our findings demonstrate the capability of planetary seismology to identify impact-generated seismic sources and constrain both impact processes and planetary interiors.

Published
2022

11. Evidence for crustal seismic anisotropy at the InSight lander site

Author

Jiaqi Li, Caroline Beghein, James Wookey, Paul Davis, Philippe Lognonné, Martin Schimmel, Eleonore Stutzmann, Matthew Golombek, Jean-Paul Montagner, William Bruce Banerdt, NASA Astrobiology Institute (US), Agence Nationale de la Recherche (France), Ministerio de Ciencia, Innovación y Universidades (España), Schimmel, Martin, and Schimmel, Martin [0000-0003-2601-4462]

Subjects
Negative radial anisotropy, SH-wave reflections, Geophysics, Space and Planetary Science, Geochemistry and Petrology, Martian crust, Earth and Planetary Sciences (miscellaneous), Physics::Geophysics
Abstract

We analyzed broadband and low-frequency events recorded on Mars and made the first detection of horizontally polarized shear wave reflections, which help constrain the crustal structure at NASA's InSight lander site. Coherent signals from five well-recorded marsquakes appear to be independent of the focal depth and are consistent with SH-wave reflections off the topmost crustal interface (8 ± 2 km). This phase confirms the existence of the ∼8 km interface in the crust and the large wave speed (or impedance) contrast across it. The range of acceptable parameters determined from the detected SH-wave reflections differs from the majority of the vertically polarized shear wave models resulting from a previous receiver function study, indicating that the velocity of the vertically polarized waves is larger than that of horizontally polarized waves. We propose that this inconsistency results from the presence of seismic anisotropy within the top crustal layer at the lander site. Modeling results show that dry- or liquid-filled cracks/fractures and igneous intrusions can reproduce the observed radial anisotropy., J.L. and C.B. were supported by NASA InSight PSP grant #80NS-SC18K1679. J.W. was supported by a UKSA Aurora Grant (ST/T0029-72/1). P.L., E.S., and J.P.M. are supported by Agence Nationale de la Recherche (MAGIS, ANR-19-CE31-0008-08; IdEx Université Paris Cité, ANR-18-IDEX-0001), and by CNES for SEIS science support. M.S. thanks SANIMS (RTI2018-095594-B-I00). This is InSight Contribution Number 237. InSight seismic data presented here (http://dx .doi .org /10 .18715 /SEIS .INSIGHT.XB _2016) is publicly available through the Planetary Data System (PDS) Geo-sciences node, the Incorporated Research Institutions for Seismol-ogy (IRIS) Data Management Center under network code XB, and through the data center of Institut de Physique du Globe, Paris (http://seis -insight .eu). We acknowledge NASA, CNES, their part-ner agencies and Institutions (UKSA, SSO, DLR, JPL, IPGP-CNRS, ETHZ, IC, MPS-MPG) and the flight operations team at JPL, SISMOC, MSDS, IRIS-DMC and PDS for providing SEED SEIS data. Apor-tion of the work was supported by the InSight Project at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administra-tion

Published
2022

12. InSight Pressure Data Recalibration, and Its Application to the Study of Long-Term Pressure Changes on Mars

Author

Lucas Lange, Francois Forget, Donald Banfield, Michael J. Wolff, Aymeric Spiga, Ehouarn Millour, Daniel Viúdez-Moreiras, Antoine Bierjon, Sylvain Piqueux, Claire Newman, Jorge Pla-García, and William Bruce Banerdt

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), Geophysics, Space and Planetary Science, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous), FOS: Physical sciences, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics - Earth and Planetary Astrophysics
Abstract

Observations of the South Polar Residual Cap suggest a possible erosion of the cap, leading to an increase of the global mass of the atmosphere. We test this assumption by making the first comparison between Viking 1 and InSight surface pressure data, which were recorded 40 years apart. Such a comparison also allows us to determine changes in the dynamics of the seasonal ice caps between these two periods. To do so, we first had to recalibrate the InSight pressure data because of their unexpected sensitivity to the sensor temperature. Then, we had to design a procedure to compare distant pressure measurements. We propose two surface pressure interpolation methods at the local and global scale to do the comparison. The comparison of Viking and InSight seasonal surface pressure variations does not show changes larger than +-8 Pa in the CO2 cycle. Such conclusions are supported by an analysis of Mars Science Laboratory (MSL) pressure data. Further comparisons with images of the south seasonal cap taken by the Viking 2 orbiter and MARCI camera do not display significant changes in the dynamics of this cap over a 40 year period. Only a possible larger extension of the North Cap after the global storm of MY 34 is observed, but the physical mechanisms behind this anomaly are not well determined. Finally, the first comparison of MSL and InSight pressure data suggests a pressure deficit at Gale crater during southern summer, possibly resulting from a large presence of dust suspended within the crater.

Published
2022

13. Geophysical observations of Phobos transits by InSight

Author

Simon C. Stähler, Rudolf Widmer-Schnidrig, John-Robert Scholz, Martin van Driel, Anna Magdalena Mittelholz, Kenneth Hurst, Catherine L. Johnson, Mark T Lemmon, Ralph D. Lorenz, Philippe Henri Lognonné, Nils T Mueller, Laurent Pou, Aymeric Spiga, Donald Banfield, Savas Ceylan, Constantinos Charalambous, Domenico Giardini, Francis Nimmo, Mark Paul Panning, Walter Zürn, and William Bruce Banerdt

Published
2020

14. A Comodulation Analysis of Atmospheric Energy Injection into the Ground Motion at InSight, Mars

Author

Constantinos Charalambous, Alexander E Stott, Tom Pike, John McClean, Tristram Warren, Aymeric Spiga, Donald Banfield, Raphaël F. Garcia, John Clinton, Simon C. Stähler, Sara Navarro López, Philippe Henri Lognonné, Taichi Kawamura, Martin van Driel, Maren Böse, Savas Ceylan, Amir Khan, Anna Catherine Horleston, Guénolé Orhand-Mainsant, Luis Mora Sotomayor, Naomi Murdoch, Domenico Giardini, and William Bruce Banerdt

Published
2020

Catalog

Books, media, physical & digital resources
See catalog results