Alexander Stott
A5001542401- Planetary Science and Exploration
- Astro and Planetary Science
- Seismic Waves and Analysis
- Seismology and Earthquake Studies
- Space Exploration and Technology
- Earthquake Detection and Analysis
- Geophysics and Sensor Technology
- Geology and Paleoclimatology Research
- Aeolian processes and effects
- Space Science and Extraterrestrial Life
- Seismic Imaging and Inversion Techniques
- Scientific Research and Discoveries
- earthquake and tectonic studies
- Space Satellite Systems and Control
- Spaceflight effects on biology
- Blind Source Separation Techniques
- Image and Signal Denoising Methods
- Geophysics and Gravity Measurements
- Laser-induced spectroscopy and plasma
- Geological and Geochemical Analysis
- Methane Hydrates and Related Phenomena
- Music and Audio Processing
- Underwater Acoustics Research
- Music Technology and Sound Studies
- Structural Health Monitoring Techniques
Université de Toulouse
2022-2025
Institut Superieur de l'Aeronautique et de l'Espace (ISAE-SUPAERO)
2020-2025
Johns Hopkins University Applied Physics Laboratory
2020-2022
Jet Propulsion Laboratory
2022
Imperial College London
2017-2021
Geociencias Barcelona
2020
Sorbonne Université
2020
Laboratoire de Météorologie Dynamique
2020
University of Salford
1974
British Broadcasting Corporation (United Kingdom)
1955
Seismic background noise dramatically decreased as a result of lockdown measures in place for mitigating the spread COVID-19.
Before Perseverance, Jezero crater's floor was variably hypothesized to have a lacustrine, lava, volcanic airfall, or aeolian origin. SuperCam observations in the first 286 Mars days on revealed and intrusive terrain with compositional density stratification. The dominant lithology along traverse is basaltic, plagioclase enrichment stratigraphically higher locations. Stratigraphically lower, layered rocks are richer normative pyroxene. lowest observed unit has highest inferred olivine-rich...
Two >130-meter-diameter impact craters formed on Mars during the later half of 2021. These are two largest fresh discovered by Reconnaissance Orbiter since operations started 16 years ago. The impacts created seismic events (magnitudes greater than 4) recorded InSight its 3-year mission. combination orbital imagery and ground motion enables investigation subsurface atmospheric energy partitioning process a planet with thin atmosphere first direct test martian deep-interior models known...
The InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) mission began collecting high quality seismic data on Mars in February 2019. This manuscript documents the seismicity observed by SEIS, InSight's seismometer, from this time until end of March 2020. Within project, Marsquake Service (MQS) is responsible for prompt review all collected InSight, detection events that are likely to be origin, curation release catalogues. In first year collection, MQS...
Abstract The instrument package SEIS (Seismic Experiment for Internal Structure) with the three very broadband and short‐period seismic sensors is installed on surface Mars as part of NASA's InSight Discovery mission. When compared to terrestrial installations, deployed in a harsh wind temperature environment that leads inevitable degradation quality recorded data. One ubiquitous artifact raw data an abundance transient one‐sided pulses often accompanied by high‐frequency spikes. These...
The InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) mission landed on the surface of Mars November 26, 2018. One scientific instruments in payload that is essential to SEIS package (Seismic Experiment for Interior Structure) which includes a very broadband short period seismometer. More than one year since landing, continues be fully operational has been collecting an exceptional data set contains not only signals seismic origins, but also noise...
Despite the importance of sand and dust to Mars geomorphology, weather, exploration, processes that move raise maintain Mars' ubiquitous haze produce storms have not been well quantified in situ, with missions lacking either necessary sensors or a sufficiently active aeolian environment. Perseverance rover's novel environmental Jezero crater's dusty environment remedy this. In Perseverance's first 216 sols, four convective vortices raised locally, while, on average, passed rover daily, over...
Abstract For over three Earth years the Marsquake Service has been analyzing data sent back from Seismic Experiment for Interior Structure—the seismometer placed on surface of Mars by NASA’s InSight lander. Although October 2021, seismic catalog included 951 events, until recently all these events have assessed as lying within a radius 100° InSight. Here we report two distant that occurred days each other, located far side Mars, giving us our first glimpse into Mars’ core shadow zone. The...
Abstract Before the Perseverance rover landing, acoustic environment of Mars was unknown. Models predicted that: (1) atmospheric turbulence changes at centimetre scales or smaller point where molecular viscosity converts kinetic energy into heat 1 , (2) speed sound varies surface with frequency 2,3 and (3) high-frequency waves are strongly attenuated distance in CO 2 (refs. 2–4 ). However, theoretical models were uncertain because a lack experimental data low pressure difficulty to...
Abstract Planetary defense efforts rely on estimates of the mechanical properties asteroids, which are difficult to constrain accurately from Earth. The asteroid material also important in interpretation Double Asteroid Redirection Test (DART) impact. Here we perform a detailed morphological analysis surface boulders Dimorphos using images, primary data set available DART mission. We estimate bulk angle internal friction be 32.7 ± 2. 5° our measurements roundness 34 best-resolved ranging...
Abstract Seismic observations involve signals that can be easily masked by noise injection. For the NASA Mars lander InSight, atmosphere is a significant contributor, impeding identification of seismic events for two‐thirds Martian day. While below seen at even quietest sites on Earth, amplitude also considerably lower, requiring an understanding and quantification environmental injection unprecedented levels. Mars’ ground are continuously coupled system, although atmospheric functions...
Abstract We characterize vortex and dust devils (DDs) at Jezero from pressure winds obtained with the Mars Environmental Dynamics Analyzer (MEDA) instrument on 2020 over 415 Martian days (sols) ( Ls = 6°–213°). Vortices are abundant (4.9 per sol drops >0.5 Pa correcting gaps in coverage) they peak noon. At least one every five vortices carries dust, 75% of all Δ p > 2.0 dusty. Seasonal variability was small but DDs were during a storm 152°–156°). more frequent intense terrains lower...
ABSTRACT The National Aeronautics and Space Administration’s (NASAs) Interior exploration using Seismic Investigations, Geodesy Heat Transport (InSight) lander successfully touched down on Mars in November 2018, and, for the first time, a seismometer was deployed surface of planet. seismic recordings reveal diurnal seasonal changes broadband noise level that are consistent with variations local atmospheric conditions. data include variety spectral peaks, which interpreted as wind-excited,...
Abstract We identify temporal variations in surface albedo at Jezero crater using first‐of‐their‐kind high‐cadence in‐situ measurements of reflected shortwave radiation during the first 350 sols Mars 2020 mission. Simultaneous Environmental Dynamics Analyzer (MEDA) pressure, radiative fluxes, winds, and sky brightness indicate that these changes are caused by dust devils under typical conditions a storm L s ∼ 155°. The 17% decrease is one order magnitude larger than most apparent quiescent...
Before deploying to the surface of Mars, short-period (SP) seismometer InSight mission operated on deck for a total 48 hours. This dataset can be used understand how deck-mounted seismometers in future landed missions Europa, and other planetary bodies. While operating deck, SP showed signals comparable Viking-2 near 3 Hz where sensitivity Viking instrument peaked. Wind similar patterns instrument, although amplitudes were ~80% larger given wind velocity. However, during low evening hours...
The paper is concerned with the measurement of subjective thresholds unwanted pitch and amplitude fluctuations which occur in reproduced output all types sound recording systems. are commonly known as “wow” or “flutter”, new equipment described for generating controlled this type musical other programme signals. threshold measurements thus made possible more realistic than those hitherto available, have been related only to frequency test tones. generation also described, since together....
Abstract We report the aeolian changes observed in situ by NASA's InSight lander during first 400 sols of operations: Granule creep, saltation, dust removal, and formation dark surface tracks. Aeolian are infrequent sporadic. However, on sols, when they do occur, consistently appear between noon to 3 p.m., associated with passage convective vortices periods high vortex activity. more frequent at elevated locations, such as top surfaces rocks footpads. these using, for time, simultaneous...
Abstract NASA's Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) seismometer has been recording Martian seismicity since early 2019, to date, over 1,300 marsquakes have cataloged by the Marsquake Service (MQS). Due typically low signal‐to‐noise ratios (SNR) of marsquakes, their detection analysis remain challenging: while event amplitudes are relatively low, background noise large diurnal seasonal variations contains various signals originating from...
The seismic events from the NASA InSight mission have provided a groundbreaking opportunity to explore internal structure of Mars, its crust core. Events are catalogued by MarsQuake Service (MQS) into several classes based on their frequency content and signal noise ratio. This classification has useful framework in which decode Martian seismicity. In this work we will highlight newly observed features P-wave coda these add effort.A prominent feature event waveforms Mars is scattering,...