Publications by authors named "R Widmer-Schnidrig"
Article Synopsis
- * In September 2023, researchers detected a significant seismic signal from East Greenland that corresponded to a rock-ice avalanche leading to a tsunami in Dickson Fjord.
- * The study reveals that the tsunami transformed into a 7-meter-high long-duration seiche, demonstrating the interplay between glacial melting and geological hazards, emphasizing the dangerous effects of climate change on these environments.
Seismic detection of a deep mantle discontinuity within Mars by InSight.
Proc Natl Acad Sci U S A
October 2022
Article Synopsis
- Scientists are studying the inside of Mars to learn how it formed and changed over time, focusing on its deep mantle where certain minerals change under pressure.
- They found evidence of a special boundary in Mars' mantle using data from NASA's InSight Mission, which helps understand its temperature and composition.
- Their research suggests that the Martian mantle is colder and contains more iron than Earth's, and they’ve narrowed down possible compositions that match the boundary they observed.
The Seismic Experiment for Interior Structure (SEIS) of the mission to Mars, has been providing direct information on Martian interior structure and dynamics of that planet since it landed. Compared to seismic recordings on Earth, ground motion measurements acquired by SEIS on Mars are made under dramatically different ambient noise conditions, but include idiosyncratic signals that arise from coupling between different sensors and spacecraft components. This work is to synthesize what is known about these signal types, illustrate how they can manifest in waveforms and noise correlations, and present pitfalls in structural interpretations based on standard seismic analysis methods.
View Article and Find Full Text PDFFor 2 years, the InSight lander has been recording seismic data on Mars that are vital to constrain the structure and thermochemical state of the planet. We used observations of direct ( and ) and surface-reflected (, , , and ) body-wave phases from eight low-frequency marsquakes to constrain the interior structure to a depth of 800 kilometers. We found a structure compatible with a low-velocity zone associated with a thermal lithosphere much thicker than on Earth that is possibly related to a weak -wave shadow zone at teleseismic distances.
View Article and Find Full Text PDFArticle Synopsis
- Dark matter might consist of compact dark objects (CDOs) that interact weakly with normal matter and can move within the Earth.
- A CDO in the Earth's inner core has a roughly 55-minute orbital period, which could create time-varying signals detectable by gravimeters.
- Current data from superconducting gravimeters suggest CDOs can only exist inside the Earth if their mass and orbital radius are extremely small, specifically if their product is less than 1.2×10^{-13} times the mass and radius of Earth.