Antoine Lucas

French National Centre for Scientific Research | CNRS · Institut de Physique du Globe de Paris

Within the Valles Marineris region on Mars, a huge system of interconnected valleys interpreted as flood channels reveals the presence of braided channels and strong incisions into the bedrock. We focus our study on Ganges Chasma, where two examples of outflow channels lie on the Valles Marineris plateau and take source in depressions. These channe...

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 occurren...

In May 1965, a main landslide occurred in a deeply incised valley of Piton de la Fournaise volcano, in Réunion Island. This event occurred one day after heavy rainfalls and was consequently interpreted as a mud/debris flow. We take advantage of several sets of historical photographs to reappraise this event. They show that the collapse of a large p...

We develop a phenomenological model of suspended sediment transport on the basis of data acquired in the Capesterre river, which drains a small tropical catchment in Guadeloupe. The model correctly represents the concentration of suspended sediment during floods, provided that the relation between concentration and water level forms a counterclockw...

On December 15th 1952, at approximately 14:00 local time a mass of 5.9 × 10⁶ m³ of permafrozen talus deposits failed in a landslide close to the Niiortuut mountain on the south coast of the Nuussuaq peninsula, central West Greenland. Between 1.8 and 4.5 × 10⁶ m³ of the material entered the sea and generated a tsunami that propagated through the Vai...

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) seism...

To monitor the effects of rapid changes in climate and land use on sediment export from erodible environments, it is crucial to accurately quantify highly fluctuating suspended sediment concentrations (SSCs) in contrasted river systems that drain small to mesoscale catchments. To this end, we investigate the turbidity-based quantification of SSCs i...

Extreme precipitation events play a pivotal role in shaping Earth’s surface through their influences on hillslope processes and sediment transport in rivers. In this study, we focus on understanding the implications of such events on sediment transport, using Réunion Island as a natural laboratory due to its intense tropical rainfall regime. Throug...

The evergrowing amount of planetary LiDAR data has enabled extensive Inter-Planetary Comparative Studies (IPCS) where feature extraction is a vital task. GPU-based parallelism can efficiently handle such data, yet existing solutions fail to extract (1) user-customizable and (2) multi-scale features. In this paper, we propose a GPU-based feature ext...

The S1222a marsquake detected by InSight on 4 May 2022 was the largest of the mission, at MwMa ${M}_{w}^{Ma}$ 4.7. Given its resemblance to two other large seismic events (S1000a and S1094b), which were associated with the formation of fresh craters, we undertook a search for a fresh crater associated with S1222a. Such a crater would be expected to...

Motivation: On May 5, 2022, the martian SEIS seismometer recorded an unprecedented M Ma W 4.7 Marsquake. The epicenter is located at 3.0 • S, 171.9 • E. The areas is barely flat with only a few N-S tectonic-like features. Most unfilled impact craters and ridges show dust avalanches (a.k.a. Slope streaks). We investigate the post-seismic outcomes in...

Potential dust avalanches as aftermaths of the seismic event of S1222a detected by the SEIS/InSight seismometer are investigated. Orbital observations emphasize that the area around the estimated location shows rather flat topography with North-South ridge structures. Thermal inertia data attests that the surface is essentially composed of granular...

During the last four years, the InSight mission has recorded more than 1,300 seismic events on Mars. The first surprising observation was the detection of a localized seismic activity along one of the youngest structures around the landing site: Cerberus Fossae. We jointly present results of a tectonic analysis of this giant fracture network of ~12...

p>In recent decades, with the placement of LiDAR remote sensing instruments in orbit, we now have global coverage of the bare-ground elevation on the Earth, Mars and beyond. Encoded in such planetary LiDAR data are interesting landscape features that promise to further our knowledge of planetary topography. However, discovery of such features entai...

When the Hale impact crater penetrated the martian cryosphere 1Ga, landforms indicating post-impact volatile mobilisation were generated. We have found landforms in the ejecta blanket of Hale Crater similar to ‘permafrost molards’ found in periglacial environments on Earth, and probably related to the past or present presence of volatiles at/near t...

p>In recent decades, with the placement of LiDAR remote sensing instruments in orbit, we now have global coverage of the bare-ground elevation on the Earth, Mars and beyond. Encoded in such planetary LiDAR data are interesting landscape features that promise to further our knowledge of planetary topography. However, discovery of such features entai...

p>In recent decades, with the placement of LiDAR remote sensing instruments in orbit, we now have global coverage of the bare ground elevation on the Earth, Mars and beyond. Encoded in such planetary LiDAR data are interesting landscape features that promise to further our knowledge of planetary topography. However, discovery of such features comes...

We develop a phenomenological model of suspended-sediment transport on the basis of data acquired in the Capesterre river, which drains a small tropical catchment in Guadeloupe. The model correctly represents the transport of suspended sediment during floods, provided that the relation between concentration and water-level forms a counterclockwise...

The Selk crater region is the future landing site of NASA’s Dragonfly mission to Titan. The region was imaged by the Cassini RADAR at incidence angles from 5° to 72° and at various polarization angles. Using this data set, we mapped six terrain units and assembled a backscatter curve for each, providing normalized backscatter cross section ( σ ⁰ )...

Since early 2019, the InSight mission has proven that Mars is seismically active, with more than 900 seismic events recorded. Among them, several events have characteristics close to terrestrial tectonic earthquakes. Most of these events are located on the major graben system of Cerberus Fossae and, a little further north, on the secondary system o...

Titan's rich and dense atmosphere, composed mainly of methane and nitrogen, maintains a methane cycle that shapes its surface, like the water cycle on Earth. Methane precipitations erodes Titan's surface and forms complex river networks observed at all latitudes by the Cassini-Huygens mission. However, precipitation rates are poorly constrained and...

The NASA InSight mission to Mars successfully landed on 26 November 2018 in Elysium Planitia. It aims to characterize the seismic activity and aid in the understanding of the internal structure of Mars. We focus on the Cerberus Fossae region, a giant fracture network ∼1,200 km long situated east of the InSight landing site where M ∼3 marsquakes wer...

In response to ESA’s “Voyage 2050” announcement of opportunity, we propose an ambitious L-class mission to explore one of the most exciting bodies in the Solar System, Saturn’s largest moon Titan. Titan, a “world with two oceans”, is an organic-rich body with interior-surface-atmosphere interactions that are comparable in complexity to the Earth. T...

The rate of occurrence of High Frequency (HF) marsquakes, as recorded by InSight at Homestead Hollow, Elysium Planitia, increased after about LS=33∘, and ceased almost completely by LS=187∘, following an apparently seasonal variation with a peak rate near aphelion. We define seismic rate models based on the declination of the Sun, annual solar tide...

div> On the seasonal time scale, for accessible locations and when manpower is available, direct observations and field survey are the most useful and standard approaches. However very limited studies have been conducted on direct observation at the decennial to century time-scale due to observational constrains. Here, we present an open and repr...

On the seasonal time scale, for accessible locations and when manpower is available, direct observations and field survey are the most useful and standard approaches. However very limited studies have been conducted on direct observation at the decennial to century time-scale due to observational constrains. Here, we present an open and reproducibl...

In response to ESA Voyage 2050 announcement of opportunity, we propose an ambitious L-class mission to explore one of the most exciting bodies in the Solar System, Saturn largest moon Titan. Titan, a "world with two oceans", is an organic-rich body with interior-surface-atmosphere interactions that are comparable in complexity to the Earth. Titan i...

div> On the seasonal time scale, for accessible locations and when manpower is available, direct observations and field survey are the most useful and standard approaches. However very limited studies have been conducted on direct observation at the decennial to century time-scale due to observational constrains. Here, we present an open and repr...

div> On the seasonal time scale, for accessible locations and when manpower is available, direct observations and field survey are the most useful and standard approaches. However very limited studies have been conducted on direct observation at the decennial to century time-scale due to observational constrains. Here, we present an open and repr...

div> On the seasonal time scale, for accessible locations and when manpower is available, direct observations and field survey are the most useful and standard approaches. However very limited studies have been conducted on direct observation at the decennial to century time-scale due to observational constrains. Here, we present an open and repr...

div> On the seasonal time scale, for accessible locations and when manpower is available, direct observations and field survey are the most useful and standard approaches. However very limited studies have been conducted on direct observation at the decennial to century time-scale due to observational constrains. Here, we present an open and repr...

Context. The effects of space weathering and other alteration processes on the upper surface of Saturn’s icy moons are yet to be explored. Aims. We present a thermophysical model parametrised by way of regolith properties such as porosity, grain size, and composition, as well as the local topography. The modelled surface temperature and apparent em...

Landslides are common features found on steep slopes on Mars and the role of water in their formation is an open question. Our study focuses on three young martian landslides whose mechanism of formation is unknown and knowing their formation mechanism could give us key information on recent martian climate and/or tectonics. They are less than 5 km...

For the 2007 International Forum on Landslide Disaster Management framework, our team performed several numerical simulations on both theoretical and natural cases of granular flows. The objective was to figure out the ability and the limits of our numerical model in terms of reproduction and prediction. Our benchmarking exercises show that for alm...

We report the aeolian changes observed in situ by NASA's InSight lander during the first 400 sols of operations: Granule creep, saltation, dust removal, and the formation of dark surface tracks. Aeolian changes are infrequent and sporadic. However, on sols, when they do occur, they consistently appear between noon to 3 p.m., and are associated with...

Depth‐averaged thin‐layer models are commonly used to model rapid gravity‐driven flows such as debris flows or debris avalanches. However, the formal derivation of thin‐layer equations for general topographies is not straightforward. The curvature of the topography results in a force that maintains the velocity tangent to the topography. Another cu...

Statistische Analyse der zeitlichen Verteilung von High Frequency Marsquakes, nachweis einer zeitlich variablen eventrate und quantitatives ranking möglicher physikalischer mechanismen.

EP023-08 The NASA InSight mission on Mars is a unique opportunity to study atmospheric processes both from orbit and in situ observations. We use post-landing high-resolution satellite images (HiRISE) to monitor dust devil activity during almost one martian year. We detected and mapped newly formed dust devil tracks and analyze their characteristic...

River valleys have been observed on Titan at all latitudes by the Cassini‐Huygens mission. Just like water on Earth, liquid methane carves into the substrate to form a complex network of rivers, particularly stunning in the images acquired near the equator by the Huygens probe. To better understand the processes at work that form these landscapes,...

A key point of landslide hazard assessment is the estimation of their runout. Empirical relations linking angle of reach to volume can be used relatively easily, but they are generally associated with large uncertainties as they do not consider the topographic specificity of a given study site. On the contrary, numerical simulations provide more de...

A new 1.5 m diameter impact crater was discovered on Mars only ~40 km from the InSight lander. Context camera images constrained its formation between 21 February and 6 April 2019; follow‐up High Resolution Imaging Science Experiment images resolved the crater. During this time period, three seismic events were identified in InSight data. We derive...

The NASA InSight mission on Mars is a unique opportunity to study atmospheric processes both from orbit and in situ observations. We use post-landing high-resolution satellite images to monitor dust devil activity during the first eight months of the mission. We perform mapping and semi-automatic detection of newly formed dust devil tracks and anal...

Mass wasting erodes hillslopes and supplies sediments to catchment rivers (Schuster & Highland, 2007). To assess sediment transports in drainage networks, it is crucial to (1) estimate the volume of sediment delivered to the drainage network, and (2) evaluate the time needed and processes involved in rivers to evacuate these sediments out of the wa...

The InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) mission landed in Elysium Planitia on Mars on 26 November 2018 and fully deployed its seismometer by the end of February 2019. The mission aims to detect, characterize and locate seismic activity on Mars, and to further constrain the internal structure, comp...

The atmosphere of Mars is thin, although rich in dust aerosols, and covers a dry surface. As such, Mars provides an opportunity to expand our knowledge of atmospheres beyond that attainable from the atmosphere of the Earth. The InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) lander is measuring Mars’s atmosph...

The atmosphere of Mars is thin, although rich in dust aerosols, and covers a dry surface. As such, Mars provides an opportunity to expand our knowledge of atmospheres beyond that attainable from the atmosphere of the Earth. The InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) lander is measuring Mars’s atmosph...

Die Aktivität der sog. High Frequency Marsbeben (Ereignisse mit einem Frequenzgehalt dominant oberhalb von 2.4 Hz) nahm von Mai bis August 2019 zunächst stark zu, hielt dann (während des Nord-Sommers) auf hohem Niveau an und klang im Frühjahr 2020 fast vollständig ab. Es ist vorgeschlagen worden (Manga et al., 2019, https://doi.org/10.1029/2019GL08...

Mountainous landscape evolution under tropical and alpine environments is mainly dictated by climatic forcing which influences underlying mechanisms of geomorphic transport (e.g., soil formation, river dynamics, slope stability and mass wasting). The time scale over which this influence acts ranges from seasonal to decennial time span. On the seaso...

The texture, composition, and morphology of dunes observed in the equatorial regions of Titan may reflect present and/or past climatic conditions. Determining the physio‐chemical properties and the morphodynamics of Titan's dunes is therefore essential to understanding of the climatic and geological history of the largest moon of Saturn. We quantit...

InSight landed on Mars on November 26, 2018 in western Elysium Planitia. The Mars crust beneath the lander is subject to complex geologic history next to the great topographic and crustal dichotomy of Mars. Understanding this part of the Martian crust in the subsurface would aid future investigations of the internal structure of the planet based on...

The texture, composition, and morphology of dunes observed in the equatorial regions of Titan may reflect present and/or past climatic conditions. Determining the physio‐chemical properties and the morphodynamics of Titan's dunes is therefore essential to understanding of the climatic and geological history of the largest moon of Saturn. We quantit...

Supplementary Information of manuscript Texture and composition of Titan's equatorial sand seas inferred from Cassini SAR data: Implications for aeolian transport and dune morphodynamics A. Lucas, S. Rodriguez, F. Lemonnier*, A. Le Gall, S. MacKenzie, C. Ferrari, Ph. Paillou, C. Narteau Accepted for JGR-E, 2019JE005965, pre-print is available on ar...

In this white paper, we present a cross-section of important scientific questions that remain partially or completely unanswered, ranging from Titan exosphere to the deep interior, and we detail which instrumentation and mission scenarios should be used to answer them. Our intention is to formulate the science goals for the next generation of plane...

Titan, Saturn’s largest moon, hosts lakes and seas of liquid hydrocarbons at its poles¹. General circulation models demonstrate that regional evaporation and precipitation rates of methane are likely to change with the seasons (Titan’s year is 29.5 Earth years) and evolve on a geological timescale (~10⁵ Earth years)2–4. Cassini observations suggest...