Publications
162 results found
Charalambous C, Pike T, Fernando B, et al., 2024, Small-scale Structure of the Martian Mantle
<jats:p>The InSight mission's SEIS instrument has provided a unique opportunity to probe the deep interior of Mars. This seismic exploration of the Martian interior has emerged as a promising avenue for revealing the enigmatic geophysical properties and dynamic processes within the planet's mantle.In this study, we present an analysis of the seismic signature of marsquakes which transit deep into the mantle, providing crucial information on the seismic velocity profile and potential heterogeneities. The quakes show a characteristic late emergence of the first energy at higher frequencies which can be analysed as due to the scattering of seismic energy as it transits the mantle. From this we are able to quantify the size distribution of the mantle's small-scale heterogeneity as well as to constrain the rheological properties and convective vigor of the Martian mantle.As unlike Earth, Mars has sealed its mantle contents under a stagnant lid, we use our observations to provide evidence about the early stages of planetary formation and differentiation on Mars. Our findings contribute to the better understanding of the Martian mantle's geodynamics and allow a comparative assessment of the evolution of planetary interiors that likely apply to other planets that lack plate tectonics.</jats:p>
Pike WT, Charalambous C, Calcutt S, et al., 2024, A compact MEMS gravimeter with sub ng performance
<jats:p>We present the performance of a MEMS accelerometer capable of sub-migroGal Allan variance out to a period of 1000 s. The gravimeter incorporates a monocrystalline silicon suspension and capacitive sensing with electromagnetic feedback. The gravimeter is capable of operation over 10 degree tilt range under Earth gravity, allowing unsupervised operation after remote deployment with a three-axis gapleran geometry. The suspension incorporates temperature compensation to minimse the need for thermal isolation. &#160;The overall mass of the instrument is about 0.6 kg mass, &#160;including the packaged sensor heads, the electronics board and associated connectors and cabling with a power requirement of less than 400 mW. &#160;The performance and resource profile make this a promising instrument for both terrestrial deployment in extreme environments as well as planetary deployment.</jats:p>
Charalambous C, Golombek M, Pike T, et al., 2023, The Aeolian Activity at InSight Over Two Martian Years
<jats:p>Aeolian activity, the movement of sand and dust by the wind, is common on Earth and has been observed on other planets [1]. Under the current climatic conditions on Mars, aeolian activity is the primary process of surface modification driven by winds, dust storms and wind vortices. Landed and orbiting cameras show that widespread aeolian activity occurs despite low measured and modelled winds, challenging Earth-based theories [2, 3]. Dust particles enter into long-term suspension forming global dust storms which drastically alter the Martian atmospheric dynamics and present hazards to robotic and human missions.Several models have been proposed on the long-standing conundrum of sediment transport on Mars, however, none of these have been verified on the planet. The outstanding question of what wind shear velocities mobilize sediments on Mars has remained elusive despite multiple spacecrafts carrying wind sensors and studying aeolian activity on finer spatial and temporal scales than can be achieved in orbit. Quantitative examination of aeolian activity under natural Martian surface conditions is imperative in validating transport models.The InSight lander has provided a unique opportunity for monitoring simultaneous coverage of aeolian activity on Mars by combining, for the first time, imaging with atmospheric, seismic and magnetic measurements. Previous studies spanned over just half of the first Martian year, from the end of northern winter to midsummer, and observed minor aeolian activity limited to sporadic grain motion and dust devil tracks [4, 5].In this study, we extend observations of aeolian activity for two Martian years, allowing us to infer the seasonal evolution at the landing site. We report a series of remarkable daytime vortex-induced events with pressure excursions up to 10 Pa, including an investigation of the burst in daytime vortices and emergence of nighttime vortices in northern autumn. Despite our observations reinforcing the qui
Standley IM, Pike WT, Calcutt S, et al., 2023, Short Period Seismometer for the Lunar Farside Seismic Suite Mission, IEEE Aerospace Conference, Publisher: IEEE, ISSN: 1095-323X
Lognonne P, Banerdt WB, Clinton J, et al., 2023, Mars Seismology, ANNUAL REVIEW OF EARTH AND PLANETARY SCIENCES, Vol: 51, Pages: 643-670, ISSN: 0084-6597
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- Citations: 7
Li J, Beghein C, McLennan SM, et al., 2022, Constraints on the martian crust away from the InSight landing site, NATURE COMMUNICATIONS, Vol: 13
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- Citations: 3
Ceylan S, Clinton JF, Giardini D, et al., 2022, The marsquake catalogue from InSight, sols 0-1011, PHYSICS OF THE EARTH AND PLANETARY INTERIORS, Vol: 333, ISSN: 0031-9201
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- Citations: 19
Kim D, Banerdt WB, Ceylan S, et al., 2022, Surface waves and crustal structure on Mars, SCIENCE, Vol: 378, Pages: 417-421, ISSN: 0036-8075
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- Citations: 29
Posiolova LV, Lognonné P, Banerdt WB, et al., 2022, Largest recent impact craters on Mars: Orbital imaging and surface seismic co-investigation., Science, Vol: 378, Pages: 412-417, ISSN: 0036-8075
Two >130-meter-diameter impact craters formed on Mars during the later half of 2021. These are the two largest fresh impact craters discovered by the Mars Reconnaissance Orbiter since operations started 16 years ago. The impacts created two of the largest seismic events (magnitudes greater than 4) recorded by InSight during its 3-year mission. The combination of orbital imagery and seismic ground motion enables the investigation of subsurface and atmospheric energy partitioning of the impact process on a planet with a thin atmosphere and the first direct test of martian deep-interior seismic models with known event distances. The impact at 35°N excavated blocks of water ice, which is the lowest latitude at which ice has been directly observed on Mars.
Huang Q, Schmerr NC, King SD, et al., 2022, Seismic detection of a deep mantle discontinuity within Mars by InSight, PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, Vol: 119, ISSN: 0027-8424
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- Citations: 9
Brinkman N, Schmelzbach C, Sollberger D, et al., 2022, In Situ Regolith Seismic Velocity Measurement at the InSight Landing Site on Mars, JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS, Vol: 127, ISSN: 2169-9097
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- Citations: 4
Charalambous C, Pike T, Fernando B, et al., 2022, Denoising InSight: Determination of Mars&#8217; lateral crustal variations through surface-wave identification
<jats:p>&lt;p&gt;For over three Earth years, NASA&amp;#8217;s InSight mission has returned data from the Seismic Experiment for Interior Structure (SEIS) on Mars with over 1300 recorded marsquakes (Horleston et al., this issue), leading to numerous breakthroughs in determining the planet's structure (Khan et al., 2021; St&amp;#228;hler et al., 2021; Knapmeyer-Endrun et al., 2021). However, a large number of detected marsquakes are contaminated by SEIS&amp;#8217;s complex interaction with the Martian atmosphere which injects noise and couples into the seismic signal. Identification of surface waves, polarisation analysis and clear body-wave arrivals is therefore often inhibited by this strong atmospheric noise. Despite numerous identifications, only 12 events have so far been fully located. Detection and analysis of the seismic component thus requires separation from such aseismic signal sources.&lt;/p&gt;&lt;p&gt;Here we present a novel denoising model which exploits the strong correlation between the ground motion and the atmospheric conditions recorded at InSight. The approach exploits linearities in the noise injected by the atmosphere by using weather data measured by the lander, or in the absence of such data due to power constraints, the excitation of wind-sensitive lander modes that have been proven an effective atmospheric proxy in estimating this injection on Mars (Charalambous et al., 2021; Clinton et al., 2021; Dahmen et al., 2021). The output results in &amp;#8220;demodulation&amp;#8221;, i.e., the cancellation of any environmental noise and the effective isolation of the seismic signal power in time-frequency space. Our denoising approach is thus able to remove and decouple the environmental noise from the seismic signal to reveal features in the seismic event waveform that were previously hidden in the noise.&lt;/p&gt;&lt;p&gt;U
Knapmeyer M, Stahler SC, Daubar I, et al., 2021, Seasonal seismic activity on Mars, EARTH AND PLANETARY SCIENCE LETTERS, Vol: 576, ISSN: 0012-821X
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- Citations: 7
Zweifel P, Mance D, ten Pierick J, et al., 2021, Seismic High-Resolution Acquisition Electronics for the NASA InSight Mission on Mars, BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA, Vol: 111, Pages: 2909-2923, ISSN: 0037-1106
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- Citations: 9
Kim D, Davis P, Lekic V, et al., 2021, Potential Pitfalls in the Analysis and Structural Interpretation of Seismic Data from the Mars <i>InSight</i> Mission, BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA, Vol: 111, Pages: 2982-3002, ISSN: 0037-1106
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- Citations: 32
Hurst K, Fayon L, Knapmeyer-Endrun B, et al., 2021, Resonances of the InSight Seismometer on Mars, BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA, Vol: 111, Pages: 2951-2963, ISSN: 0037-1106
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- Citations: 14
Stott AE, Charalambous C, Warren TJ, et al., 2021, The Site Tilt and Lander Transfer Function from the Short-Period Seismometer of InSight on Mars, BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA, Vol: 111, Pages: 2889-2908, ISSN: 0037-1106
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- Citations: 5
Dahmen NL, Zenhausern G, Clinton F, et al., 2021, Resonances and Lander Modes Observed by InSight on Mars (1-9 Hz), BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA, Vol: 111, Pages: 2924-2950, ISSN: 0037-1106
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- Citations: 24
Sollberger D, Schmelzbach C, Andersson F, et al., 2021, A Reconstruction Algorithm for Temporally Aliased Seismic Signals Recorded by the InSight Mars Lander., Earth Space Sci, Vol: 8, ISSN: 2333-5084
In December 2018, the NASA InSight lander successfully placed a seismometer on the surface of Mars. Alongside, a hammering device was deployed at the landing site that penetrated into the ground to attempt the first measurements of the planetary heat flow of Mars. The hammering of the heat probe generated repeated seismic signals that were registered by the seismometer and can potentially be used to image the shallow subsurface just below the lander. However, the broad frequency content of the seismic signals generated by the hammering extends beyond the Nyquist frequency governed by the seismometer's sampling rate of 100 samples per second. Here, we propose an algorithm to reconstruct the seismic signals beyond the classical sampling limits. We exploit the structure in the data due to thousands of repeated, only gradually varying hammering signals as the heat probe slowly penetrates into the ground. In addition, we make use of the fact that repeated hammering signals are sub-sampled differently due to the unsynchronized timing between the hammer strikes and the seismometer recordings. This allows us to reconstruct signals beyond the classical Nyquist frequency limit by enforcing a sparsity constraint on the signal in a modified Radon transform domain. In addition, the proposed method reduces uncorrelated noise in the recorded data. Using both synthetic data and actual data recorded on Mars, we show how the proposed algorithm can be used to reconstruct the high-frequency hammering signal at very high resolution.
Khan A, Ceylan S, van Driel M, et al., 2021, Upper mantle structure of Mars from InSight seismic data, SCIENCE, Vol: 373, Pages: 434-+, ISSN: 0036-8075
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- Citations: 88
Stahler SC, Khan A, Banerdt WB, et al., 2021, Seismic detection of the martian core, SCIENCE, Vol: 373, Pages: 443-+, ISSN: 0036-8075
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- Citations: 131
Charalambous C, McClean JB, Baker M, et al., 2021, Vortex-Dominated Aeolian Activity at InSight's Landing Site, Part 1: Multi-Instrument Observations, Analysis, and Implications, JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS, Vol: 126, ISSN: 2169-9097
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- Citations: 21
Brinkman N, Stahler SC, Giardini D, et al., 2021, First Focal Mechanisms of Marsquakes, JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS, Vol: 126, ISSN: 2169-9097
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- Citations: 37
Compaire N, Margerin L, Garcia RF, et al., 2021, Autocorrelation of the Ground Vibrations Recorded by the SEIS-InSight Seismometer on Mars, JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS, Vol: 126, ISSN: 2169-9097
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- Citations: 30
Charalambous C, Stott AE, Pike WT, et al., 2021, A Comodulation Analysis of Atmospheric Energy Injection Into the Ground Motion at InSight, Mars, JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS, Vol: 126, ISSN: 2169-9097
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- Citations: 24
van Driel M, Ceylan S, Clinton JF, et al., 2021, High-Frequency Seismic Events on Mars Observed by InSight, JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS, Vol: 126, ISSN: 2169-9097
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- Citations: 34
Nunn C, Pike WTT, Standley IMM, et al., 2021, Standing on Apollo's Shoulders: A Microseismometer for the Moon, PLANETARY SCIENCE JOURNAL, Vol: 2
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- Citations: 6
Dahmen NL, Clinton JF, Ceylan S, et al., 2021, Super High Frequency Events: A New Class of Events Recorded by the InSight Seismometers on Mars, JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS, Vol: 126, ISSN: 2169-9097
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- Citations: 19
Ceylan S, Clinton JF, Giardini D, et al., 2021, Companion guide to the marsquake catalog from InSight, Sols 0-478: Data content and non-seismic events, PHYSICS OF THE EARTH AND PLANETARY INTERIORS, Vol: 310, ISSN: 0031-9201
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- Citations: 53
Clinton JF, Ceylan S, van Driel M, et al., 2021, The Marsquake catalogue from InSight, sols 0-478, PHYSICS OF THE EARTH AND PLANETARY INTERIORS, Vol: 310, ISSN: 0031-9201
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- Citations: 73
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