About

Mathieu Lapôtre is an Assistant Professor of Earth and Planetary Sciences at Stanford University, with courtesy appointments in Geophysics and Civil and Environmental Engineering. He leads the Earth & Planetary Surface Processes group, focusing his research on the physics behind sedimentary and geomorphic processes that shape planetary surfaces, including Earth's. His work aims to understand what sedimentary rocks reveal about the past hydrology, climate, and habitability of planets. Dr. Lapôtre holds a Ph.D. in Geology from the California Institute of Technology, obtained in 2017, and has earned multiple master's degrees in planetary science, geophysical engineering, and environmental science & engineering from Caltech, Ecole & Observatoire des Sciences de la Terre, and Université de Strasbourg, respectively. His educational background and research focus are centered on planetary surface processes, sedimentology, and geomorphology, contributing to the understanding of planetary environments and their histories.

Research topics

• Earth science
• Geology
• Astrobiology
• Computer Science
• Artificial Intelligence
• Paleontology
• Physics
• Environmental science
• Geography
• Ecology
• Geophysics
• Geomorphology
• Astronomy
• Physical geography

Selected publications

• Data (detected boulders, rock abundance maps, and more) for the manuscript "Effect of boulder-size distributions on thermally derived rock abundances on the Moon"

  Zenodo (CERN European Organization for Nuclear Research) · 2026-01-06 · 1 citations

  datasetOpen accessSenior author
  PublisherDOI

• Effect of Boulder‐Size Distributions on Thermally Derived Rock Abundances on the Moon

  Journal of Geophysical Research Planets · 2026-03-01

  articleOpen accessSenior author

  Abstract Rock abundance, defined as the surface's fractional area covered by rocks, is used to characterize the Moon's regolith, decipher its impact history, and assess potential landing sites. By definition, it should be agnostic to rock‐size distributions. However, it has been suggested that rock abundances, derived from surface temperatures measured by the Lunar Reconnaissance Orbiter (LRO) Diviner radiometer, are not. Systematic analyses of the effect of rock‐size distributions on Diviner‐derived rock abundances have been hindered by the laborious nature of manually mapping individual boulders from optical images. Here, we conduct such an analysis from automated boulder detections in high‐resolution LRO Narrow Angle Camera images using BoulderNet, a boulder segmentation machine‐learning model. We present a comparison of BoulderNet‐ and Diviner‐derived rock abundances and find that, although both data sets are strongly correlated, rock abundances derived from thermophysical modeling are underestimated in areas with a greater proportion of smaller rocks relative to larger ones.

  PublisherDOI

• Remote Compositional Analyses of Space-weathered Lunar Maria

  The Planetary Science Journal · 2026-01-01

  articleOpen access

  Abstract Visible-to-shortwave infrared (VSWIR) reflectance spectroscopy has revolutionized our understanding of planetary surface compositions. However, space-weathering processes on airless bodies complicate quantitative compositional analyses. Here, we present a framework to isolate the signatures of space weathering in VSWIR spectra of lunar maria by leveraging radiative transfer modeling under the assumptions that (i) a space-weathered target can be expressed as a mixture of fresh and fully space-weathered components and (ii) remaining signatures can be modeled by including agglutinates as an end-member component. We first validate this approach against laboratory spectra of space-weathered Apollo mare soils of known mineral compositions using a probabilistic Markov Chain Monte Carlo implementation of the Hapke radiative transfer model. Second, we illustrate how this approach can be applied to orbital Moon Mineralogy Mapper data. The proposed space-weathering correction workflow for lunar maria could be expanded to other lunar lithologies and applied to existing and future data sets.

  PublisherDOI

• Aerodynamic roughness of rippled beds under active saltation at Earth-to-Mars atmospheric pressures

  Nature Communications · 2025-06-02 · 5 citations

  articleOpen access

  As winds blow over sand, grains are mobilized and reorganized into bedforms such as ripples and dunes. In turn, sand transport and bedforms affect the winds themselves. These complex interactions between winds and sediment render modeling of windswept landscapes challenging. A critical parameter in such models is the aerodynamic roughness length, z0, defined as the height above the bed at which wind velocity predicted from the log law drops to zero. In aeolian environments, z0 can variably be controlled by the laminar viscous sublayer, grain roughness, form drag from bedforms, or the saltation layer. Estimates of z0 are used on Mars, notably, to predict wind speeds, sand fluxes, and global circulation patterns; yet, no robust measurements of z0 have been performed over rippled sand on Mars to date. Here, we measure z0 over equilibrated rippled sand beds with active saltation under atmospheric pressures intermediate between those of Earth and Mars. Extrapolated to Mars, our results suggest that z0 over rippled beds and under active saltation may be dominated by form drag across a plausible range of wind velocities, reaching values up to 1 cm—two orders of magnitude larger than typically assumed for flat beds under similar sediment transport conditions. Low-pressure wind tunnel experiments suggest that the aerodynamic roughness length on Mars, over rippled beds and under active saltation, may be dominated by form drag, reaching values up to two orders of magnitude larger than typically assumed.

  PublisherOA PDFDOI

• Vegetation changes the trajectory of river bends

  Science · 2025-08-21 · 10 citations

  articleSenior author

  A primary axiom in geoscience is that the evolution of plants drove global changes in river dynamics. Notably, the apparent sinuosity of rivers, derived from the variance of sediment accretion direction measured in rocks, substantially increased when land plants evolved, around 425 million years ago. This led to the hypothesis that the rise of vegetation triggered river meandering. Recent studies of barren, meandering rivers challenge this notion, but the Paleozoic shift in the geometry of river deposits remains unexplained. Here, we suggest that it occurred because vegetation changes how river bends move through space. Using satellite images to monitor river migration, we found that bank vegetation alters the orientation of point bar accretion, resulting in a 62% increase in the inferred variance of flow direction. These results explain why meandering rivers have been underrecognized in prevegetation stratigraphy.

  PublisherDOI

• Microtextural analyses of detrital zircon for paleoenvironmental interpretations of metasedimentary rocks

  Geology · 2025-10-15 · 1 citations

  articleOpen accessSenior author

  Abstract Sedimentary rocks archive the history of Earth’s surface. However, alteration by diagenesis, weathering, deformation, and metamorphism makes interpretating Earth’s earliest environments challenging and ambiguous. We show that detrital zircon grains preserve an unaltered account of transport history, even in billion-year-old sedimentary rocks. We systematically document microscopic features on modern zircon sand grains (“microtextures”) from three continental environments—aeolian, fluvial, and beach foreshore—in modern sediment and Phanerozoic sedimentary rocks of independently known transport history. Our statistical analysis reveals that microtextural assemblages can be used to diagnose transport settings in detrital zircon grains, including recycled grains. Finally, we demonstrate the applicability of zircon microtextural analyses to Precambrian metasedimentary rocks of independently but poorly constrained transport histories. Detrital zircon grains preserve an untapped account of early surface environments, expanding the applicability of sand microtextural analyses to the first 90% of Earth’s history.

  PublisherOA PDFDOI

• Archean eolian dynamics, deposits, and indicators of other weather phenomena: Lessons from Earth and Mars

  Elsevier eBooks · 2025-12-05

  book-chapter1st authorCorresponding
  PublisherDOI

• Sticking Together: Turbulent Flocculation of Tholins to Create Saltatable Dune Sand on Titan.

  Abstracts with programs - Geological Society of America · 2025-01-01

  article
  PublisherDOI

• From Xanadu Around and Back: A ca. 11,000 km Journey of Windblown Sand Revealed by Global Dune Patterns on Titan

  Geophysical Research Letters · 2025-03-04 · 2 citations

  articleOpen access

  Abstract Extensive dune fields nearly encircle the equatorial regions of Titan, Saturn's largest moon. Dunes evolve in response to environmental change, offering a record of recent geologic and climate history. A global analysis reveals that Titan's dunes become more narrowly spaced and increasingly more regular along a continuous eastward transport path, starting east of the Xanadu region, around the equator, and terminating abruptly at Xanadu's western margin. Xanadu is a rugged, tectonically active, water‐ice‐rich region with low topography and a thin layer of atmospherically deposited organic‐rich material. Our results demonstrate that windblown grains must withstand long transport distances. Furthermore, environmental conditions along the eastern margin of Xanadu set a template over which dunes evolve, only gradually modified as sediment supply or availability increases downwind. Together, these results highlight the oversized impact that Xanadu has on Titan's dune fields, which in turn play a critical role in regulating Titan's sedimentary and carbon cycles.

  PublisherOA PDFDOI

• Ripples formed in low-pressure wind tunnels suggest Mars’s large windblown ripples are not impact ripples

  Nature Communications · 2025-03-26 · 8 citations

  articleOpen access

  Sand ripples record interactions between planetary surfaces and environmental flows, providing paleoenvironmental archives when preserved into rocks. Two main ripple types form in sand: drag ripples, common in water, and impact ripples, exclusive to windblown surfaces. Enigmatic meter-scale aeolian ripples on Mars have been assumed to be impact ripples, though ground and orbiter-based observations suggest they may be drag ripples instead. Here, we report on low-pressure wind tunnel experiments in which large ripples formed and evolved from a flat bed. Observations demonstrate that impact and large ripples grow from distinct mechanisms. Large-ripple size aligns with predictions from drag-ripple theory, and associated sand fluxes are greater than predicted for impact ripples. These findings are inconsistent with an impact-ripple origin and instead suggest that large martian ripples are drag ripples. Windblown drag ripples constitute an untapped record of atmospheric evolution on planetary bodies with tenuous or ephemeral atmospheres across the Solar System. Low-pressure wind tunnel experiments suggest that large sand ripples on Mars are drag ripples, not impact ripples. Windblown drag ripples constitute an untapped record of atmospheric evolution under tenuous atmospheres across the Solar System.

  PublisherOA PDFDOI

Frequent coauthors

• Christy Swann

  Environmental Earth Sciences

  110 shared

• D. M. Burr

  Northern Arizona University

  105 shared

• S. Diniega

  Jet Propulsion Laboratory

  104 shared

• D. A. Williams

  Arizona State University

  101 shared

• Ian J. Walker

  101 shared

• D. Banfield

  Ames Research Center

  101 shared

• R. C. Ewing

  Texas A&M University

  75 shared

• Alessandro Ielpi

  Okanagan University College

  46 shared

Labs

• Mathieu Lapôtre's LabPI

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Education

• PhD Geology, Geological & Planetary Sciences

  California Institute of Technology

  2017

• MS Planetary Science, Geological & Planetary Sciences

  California Institute of Technology

  2014