Antoine Lucas

Institut de Physique du Globe de Paris
Planetary and Space Sciences group
External envelopes geochemistry group

CNRS research scientist

About me

My research is focused on understanding the evolution of surfaces and near surfaces of the Earth and other planets, including lakes on Titan, landslides on Mars and icy satellites as well as aeolian transport on Mars, Venus and Titan. Other planets allow us to test our understanding of geological and climate processes under a wide range of conditions. By combining observations from planetary exploration missions with image processing and numerical modeling, I try to understand what controls the evolution of continental surfaces (including planetary counterparts) and more specifically mass wasting (landslides, avalanches, debris flows…), aeolian and hydrology processes. I defined mysleft as a space-hacker, an astro-geologist, a landscape-analyst and a space avalancher.

Along with my scientific activites, I am also in charge of the Natural Hazard master program at IPGP since 2023.

Recent Publications

Evidence for Erosional Efficiency of Extreme Precipitation Events at a Multi-Decadal Time Scale

E. Gayer, A. Lucas, L. Michon, and M. Gougeon

Journal of Geophysical Research - Earth Surface, 2025.

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Extreme precipitation events play a pivotal role in shaping Earth’s surface through their influences on hillslope processes (triggering mass-wasting events) and on transport capacity and dynamics of rivers. This study investigates the impact of such events on sediment transport using Réunion Island as a natural laboratory due to its intense tropical rainfall regime. Through photogrammetric techniques using historical aerial images, we reconstructed nine DEMs of the entire canyon bed of the ephemeral Rivière des Remparts spanning six decades. Based on differences in DEMs and sediment volume estimates combined with cosmogenic 3 He measurements, we assessed the spatio-temporal evolution of the entire canyon bed and the drainage of products from major landslides and rock avalanches between 1950 and 2011. Results indicate that 50.2 ± 8.4 Mm 3 (145.5 ± 24.4 Mt) of sediment was transported out of the watershed over 62 years via bed load waves. We modeled the flow dates and showed that such an export of material occurred during only 391 days over the 62 years, at an average rate of 0.13 ± 0.02 Mm 3 /day (0.37 ± 0.06 Mt/day). Our investigation confirms that sediment transport coincides with officially recorded extreme meteorological events such as cyclones. Moreover, our findings reveal that sediment transport predominantly occurs on days corresponding to highpercentile rank precipitation events, demonstrating that all transport is concentrated during these intense rainfall periods. Finally, we underscore the extremely fast conveyance of material from slopes to deep-sea fans, facilitated in Réunion by the absence of a coastal platform.
Mapping the surface characteristics of the Asal-Ghoubbet rift by massive inversion of the Hapke model on Pleiades multiangular images

D.T. Nguyen, S Jacquemoud, A. Lucas, S. Douté, C. Ferrari, S. Coustance, S. Marcq, and A. Meygret

Remote Sensing of Environment, 2025.

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A massive inversion of the Hapke model is carried out over the Asal-Ghoubbet rift (Republic of Djibouti) using high-resolution multiangular Pleiades images. This is the first time that such an inversion is performed on Earth over an entire image, previous studies having focused on planetary surfaces. This work addresses challenges such as atmospheric and geometrical corrections of these images to produce parameter maps. The use of fast Bayesian inversion significantly reduces computation times thanks to efficient exploration of the parameter space and leads to improved prediction. The parameters of the Hapke model are also interpreted in terms of surface physical properties, thanks to field measurements. Single scattering albedo is the parameter extracted with the greatest reliability, although its validation is still difficult due to the absence of a simple formula linking it to surface reflectance. Our study reveals a close relationship between photometric roughness and single scattering albedo, indicating that accurate extraction of the former is highly dependent on values of the latter, which must be below 0.8 for reliable estimation. Finally, the correlation between phase function parameters and grain properties depends on surface type and material properties.
Inferring discharge from river geometry on Titan

C. Daudon, S. Rodriguez, E. Lajeunesse, A. Lucas, and S. Jacquemoud

Geophysical Research Letters, 2025.

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Titan’s dense atmosphere, composed mainly of methane and nitrogen, maintains a methane cycle that shapes its surface. Like water on Earth, methane precipitation erodes Titan’s surface, carving river networks at all latitudes, as revealed by the Cassini-Huygens mission. On Earth, it is well known that laboratory and natural rivers exhibit a power-law relationship between their bankfull geometry and water discharge, as described by the threshold theory. Here, we investigate this hydraulic-geometric relationship on two rivers on Titan, one near the equator and the other at the south pole. We hypothesize that this relationship can be applied to any river, and test it for the first time on extraterrestrial rivers. Having shown that Titan’s rivers are consistent with the threshold theory, we use this relationship to estimate river discharge from bankfull geometry. As a perspective, we then use these discharges to infer precipitation rates, which could help to better understand Titan’s climate.
A rockslide-generated tsunami in a Greenland fjord rang Earth for 9 days

Kristian Svennevig, Stephen P. Hicks, Thomas Forbriger, Thomas Lecocq, Rudolf Widmer-Schnidrig, Anne Mangeney, Clément Hibert, Niels J. Korsgaard, Antoine Lucas, Claudio Satriano, Robert E. Anthony, Aurélien Mordret, Sven Schippkus, Søren Rysgaard, Wieter Boone, and 53 more authors

Science, 2024.

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Climate change is increasingly predisposing polar regions to large landslides. Tsunamigenic landslides have occurred recently in Greenland (Kalaallit Nunaat), but none have been reported from the eastern fjords. In September 2023, we detected the start of a 9-day-long, global 10.88-millihertz (92-second) monochromatic very-long-period (VLP) seismic signal, originating from East Greenland. In this study, we demonstrate how this event started with a glacial thinning–induced rock-ice avalanche of 25 × 10^6 cubic meters plunging into Dickson Fjord, triggering a 200-meter-high tsunami. Simulations show that the tsunami stabilized into a 7-meter-high long-duration seiche with a frequency (11.45 millihertz) and slow amplitude decay that were nearly identical to the seismic signal. An oscillating, fjord-transverse single force with a maximum amplitude of 5 × 10^11 newtons reproduced the seismic amplitudes and their radiation pattern relative to the fjord, demonstrating how a seiche directly caused the 9-day-long seismic signal. Our findings highlight how climate change is causing cascading, hazardous feedbacks between the cryosphere, hydrosphere, and lithosphere.
Possibly seismically triggered avalanches after the S1222a Marsquake and S1000a impact event

A. Lucas, I.J. Daubar, M. Le Teuff, Clement Perrin, T. Kawamura, L. Posiolova, P. Lognonné, S. Rodriguez, D. Giardini, G. Sainton, A. Mangeney, and A. Mcewen

Icarus, 2024.

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Ground motion from seismic events detected by the SEIS/InSight seismometer on Mars could potentially trigger dust avalanches. Our research strongly suggests that the seismic event S1000a may have triggered a significant number of dust avalanches. In contrast, following the seismic event S1222a, there was only a modest increase in avalanche occurrences. Orbital observations of the area surrounding the projected location of the S1222a quake reveal notable topographic features, such as North-South ridges and impact craters. We utilize orbital imagery to evaluate the rate of avalanches and explore how the S1222a event might have influenced this rate. The S1222a event appears to be a plausible factor contributing to the observed increase in avalanches. Our further analysis of the epicenter location aims to clarify how it aligns with the avalanches’ spatial distribution, offering insights into the regional topography.