Taïchi Kawamura
A5021705531- Planetary Science and Exploration
- Astro and Planetary Science
- Seismic Waves and Analysis
- Earthquake Detection and Analysis
- earthquake and tectonic studies
- Seismology and Earthquake Studies
- Space Exploration and Technology
- Geology and Paleoclimatology Research
- Space Satellite Systems and Control
- High-pressure geophysics and materials
- Seismic Imaging and Inversion Techniques
- Geological and Geochemical Analysis
- Geophysics and Sensor Technology
- Methane Hydrates and Related Phenomena
- Marine and environmental studies
- Space Science and Extraterrestrial Life
- Geophysics and Gravity Measurements
- Scientific Research and Discoveries
- Spacecraft and Cryogenic Technologies
- Geochemistry and Geologic Mapping
- Inertial Sensor and Navigation
- Underwater Acoustics Research
- Space exploration and regulation
- Pulsars and Gravitational Waves Research
- Ionosphere and magnetosphere dynamics
Institut de physique du globe de Paris
2016-2025
Centre National de la Recherche Scientifique
2017-2025
Université Paris Cité
2015-2025
Kitasato University
2025
Technische Universität Berlin
2024
National Astronomical Observatories
2023
Earthquake Engineering Research Institute
2023
Centre National d'Études Spatiales
2023
ETH Zurich
2022-2023
Sorbonne Paris Cité
2015-2022
Clues to a planet's geologic history are contained in its interior structure, particularly core. We detected reflections of seismic waves from the core-mantle boundary Mars using InSight data and inverted these together with geodetic constrain radius liquid metal core 1830 ± 40 kilometers. The large implies martian mantle mineralogically similar terrestrial upper transition zone but differing Earth by not having bridgmanite-dominated lower mantle. inferred mean density 5.7 6.3 grams per...
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...
Abstract The detection of deep reflected S waves on Mars inferred a core size 1,830 ± 40 km (ref. 1 ), requiring light-element contents that are incompatible with experimental petrological constraints. This estimate assumes compositionally homogeneous Martian mantle, at odds recent measurements anomalously slow propagating P diffracted along the core–mantle boundary 2 . An alternative hypothesis is Mars’s mantle heterogeneous as consequence an early magma ocean solidified to form basal layer...
We present the first observations of seismic waves propagating through core Mars. These observations, made using data collected by InSight geophysical mission, have allowed us to construct seismically constrained models for elastic properties Mars' core. observe core-transiting phase SKS from two farside events detected on Mars and measure travel times relative mantle traversing body waves. travels as a compressional wave, providing information about bulk modulus density. perform...
Abstract The Lunar Gravitational-wave Antenna (LGWA) is a proposed array of next-generation inertial sensors to monitor the response Moon gravitational waves (GWs). Given size and expected noise produced by lunar seismic background, LGWA would be able observe GWs from about 1 mHz Hz. This make missing link between space-borne detectors like LISA with peak sensitivities around few millihertz future terrestrial Einstein Telescope or Cosmic Explorer. In this article, we provide first...
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...
Several seismic experiments were deployed on the Moon by astronauts during Apollo missions. The began in 1969 with 11, and continued 12, 14, 15, 16 17. Instruments at 17 remained operational until final transmission 1977. These remarkable provide a valuable resource. Now is good time to review this resource, since InSight mission returning data from Mars, missions Europa are development different space agencies. We present an overview of available four sets Moon: Passive Seismic Experiments,...
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...
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 crustal structure away InSight lander. The crust north of equatorial dichotomy had shear wave approximately 3.2 kilometers per second in 5- to 30-kilometer depth range, with little variation. This implies higher density than inferred beneath lander, suggesting either compositional differences or reduced porosity volcanic areas...
Abstract Since February 2019, NASA's InSight lander is recording seismic signals on the planet Mars, which, for first time, allows to observe ongoing tectonic processes with geophysical methods. A number of Marsquakes have been located in Cerberus Fossae graben system Elysium Planitia and further west, Orcus Patera depression. We present a study focal mechanisms three well‐recorded events (S0173a, S0183a, S0235b) determine dominating source region. infer all predominantly extensional...
Abstract The seismometer deployed on the surface of Mars as part InSight mission ( In terior Exploration using S eismic I nvestigations, G eodesy and H eat T ransport) has recorded several hundreds marsquakes in first 478 sols after landing. majority these are classified high‐frequency (HF) events frequency range from approximately 1 to 10 Hz Mars' surface. All HF excite a resonance around 2.4 show two distinct but broad arrivals seismic energy that separated by up 450 s. Based content...
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 NASA's InSight has detected a large magnitude seismic event, labeled S1222a. The event moment of 4.7, with five times more compared to the second largest event. is so that features are clearly observed were not seen in any previously events. In addition body phases and Rayleigh waves, we also see Love minor arc surface wave overtones, multi‐orbit waves. At long periods, coda exceeds 10 hr. locates close North‐South dichotomy outside tectonically active Cerberus Fossae region. S1222a...