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Reposted by Mathieu Lapôtre

Stanford Doerr School of Sustainability @stanforddoerr.bsky.social · 9d

Over 100 planetary scientists from around the Bay Area recently gathered at Stanford to connect and discuss their research. Highlights:

📸 Laura Schaefer and Michelle Hill

View from the back of a large room with a person presenting slides at the front

Two people smiling holding lunar meteorites

A person presents their research during a poster session

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Reposted by Mathieu Lapôtre

Stanford Doerr School of Sustainability @stanforddoerr.bsky.social · 19d

“I’m doing something that’s merging geology and geochemistry with spacecraft. This is something I’ve been interested in since I was a kid. A lot of people in my field are obsessed with aliens, but I always was obsessed with rocks and planetary bodies.”
Meet Eva L. Scheller, new assistant professor:

Shaping planetary sciences at Stanford

Eva Scheller designs and plans spacecraft instruments, including Mars rovers and satellites, and analyzes the data to understand the formation, evolution, and habitability of planetary bodies.

stanford.io

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Reposted by Mathieu Lapôtre

Alexandra Delbot @alexandradelbot.bsky.social · 29d

Jusqu’ici, les géologues pensaient que les plantes avaient fait naître les rivières en méandres - ces grands cours d'eau en forme de S. Une nouvelle étude montre qu’elles existaient déjà avant : la végétation a seulement modifié leur façon de bouger 🌱

Explications avec du GIF végétal ⬇️

La végétation a sculpté la forme des rivières

Jusqu’ici, les géologues pensaient que les plantes avaient fait naître les rivières en méandres - ces grands cours d'eau en forme de S. Une nouvelle étude montre qu’elles existaient déjà avant : la vé...

www.radiofrance.fr

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Reposted by Mathieu Lapôtre

Stanford Doerr School of Sustainability @stanforddoerr.bsky.social · Aug 25

Findings from a recent study could upend the conventional view of how rivers have shaped continents over time.

It’s “a significant revision to our understanding of the history of the Earth,” said lead author Michael Hasson.
@marslogander.bsky.social

The rise of plant life changed how rivers move, study shows

Research reveals that unvegetated meandering rivers can geologically masquerade as braided rivers, suggesting they were much more common in the first 90 percent of Earth’s history than previously thou...

stanford.io

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Mathieu Lapôtre @marslogander.bsky.social · Aug 22

So proud of Michael!! 😎

This work was a collaboration with @alvitello.bsky.social at @unipd.bsky.social and A. Ielpi and @ubcokanagan.bsky.social

Check also:

- Perspective by J. Pizzuto: doi.org/10.1126/scie...

- Stanford’s press release: sustainability.stanford.edu/news/rise-pl...

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Mathieu Lapôtre @marslogander.bsky.social · Aug 22

Plants change how river bends move - paper by PhD student Michael Hasson out as First Release in #Science!!

Paper: doi.org/10.1126/scie...

Before #plants, #meanders did not grow laterally as much but translated downstream, making them look like braided rivers in rocks.

@stanforddoerr.bsky.social

Vegetation changes the trajectory of river bends

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 directi...

doi.org

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Carlos A. Alvarez @calvarez03.bsky.social · Jun 2

Our results suggest that on Mars, values of the aerodynamic roughness length may reach up to 1 cm—up to two orders of magnitude larger than typically assumed. #NASA Ames, @stanforddoerr.bsky.social, @marslogander.bsky.social

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Carlos A. Alvarez @calvarez03.bsky.social · Jun 2

Excited to share our latest publication in @natcomms.nature.com, where we analyze the aerodynamic roughness length over equilibrated rippled sand beds with active saltation under atmospheric pressures intermediate between those of Earth and Mars.
www.nature.com/articles/s41...

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

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 order...

www.nature.com

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Mathieu Lapôtre @marslogander.bsky.social · May 7

Best wishes to you and your family, Laurie!

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Mathieu Lapôtre @marslogander.bsky.social · Mar 27

Postdoc Carlos Alvarez shows that Mars’s large #aeolian #ripples are not impact ripples through low-pressure #wind tunnel experiments at #NASA Ames. Very excited about this one!
@stanforddoerr.bsky.social

www.nature.com/articles/s41...

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

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 t...

www.nature.com

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Mathieu Lapôtre @marslogander.bsky.social · Mar 5

New paper by PhD student @mcolinmarvin.bsky.social uses #patterns formed by #dunes to better understand sources, pathways, and sinks of #sand on #Titan. Spoiler: #Xanadu has outsized influence on #eolian sediments, and sand travels far!!

@stanforddoerr.bsky.social

M. Colin Marvin @mcolinmarvin.bsky.social · Mar 4

Check out our paper in @agu.org where we provide evidence for a continuous transport pathway around Titan’s equatorial dune fields, only interrupted by the Xanadu region (with implications for the nature of Titan’s sand grains!) agupubs.onlinelibrary.wiley.com/doi/full/10....

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Reposted by Mathieu Lapôtre

Jupiter Hansen (Cheng) @jupforjupiter.bsky.social · Feb 3

I'm giving a talk at Stanford tomorrow! If you're around, come join us. I think Zoom is an option too—details here:
events.stanford.edu/event/earth-...

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Mathieu Lapôtre @marslogander.bsky.social · Jan 16

Congrats @jtuttlekeane.bsky.social !!!!!

Mathieu Lapôtre @marslogander.bsky.social · Dec 10

Final stop with postdoc Carlos Alvarez on the "Aerodynamic #roughness of rippled beds under active #saltation at low atmospheric #pressure" (EP54A-03, 146 B).

Fr 4:20-4:30 pm.

#Wind tunnel work reveals impact of #bedforms and #saltation on #Mars.

#AGU24

(10/10)

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Mathieu Lapôtre @marslogander.bsky.social · Dec 10

Back to #Mars with PhD student Claire Blaske asking "Were #boulder fields along Mars' putative #ocean paleoshoreline deposited by a #tsunami?" (EP51B-06, 146
B).

Fr 9:25-9:35 am.

Or perhaps #floods? #glaciers? #impacts?

#AGU24

(9/10)

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Mathieu Lapôtre @marslogander.bsky.social · Dec 10

Collaborator @alvitello.bsky.social from U. Padua next will show that " #Vegetation leaves measurable imprints on the #morphodynamics or #meandering #rivers"
(EP51F-1434).

Fr 8:30 am-12:20 pm.

All about how #plants affect #meander shape!

#AGU24

(8/10)

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Mathieu Lapôtre @marslogander.bsky.social · Dec 10

PhD student Timmy Lui will take us to #Mars for his " #Segmentation of #dune crestlines using #convolutional #neural #networks"
(EP51D-1378, hall B-C).

Fr 8:30 am-12:20 pm.

A challenging task with potential to reveal much about #Mars #climate!

#AGU24

(7/10)

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Mathieu Lapôtre @marslogander.bsky.social · Dec 10

Kicking off Fr, PhD student Vittorio Colicci will present his MS work at MIT, "Examining the influence of early #tree #root geometry on #soil cohesion and anchoring strength using 3D-printed reconstructions" (EP51F-1439, hall B-C)

Fr 8:30 am-12:20 pm

#AGU24

(6/10)

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Mathieu Lapôtre @marslogander.bsky.social · Dec 10

Alternatively, undergrad Brian Amaro will talk about his "Automatic characterization of the size distribution of small #rocks on the #Moon and implications for orbiter-based extrapolations" (P44C-06, Liberty M at Marriott).

Th 4:52-5:02 pm.

#AGU24

(5/10)

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Mathieu Lapôtre @marslogander.bsky.social · Dec 10

Then former postdoc @agunn.bsky.social (now faculty at Monash) and recipient of #AGU24 's Luna Leopold award will deliver the Sharp lecture (Ballroom B). #Dunes galore on the horizon!

Th 4-5:30 pm.

(4/10)

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Mathieu Lapôtre @marslogander.bsky.social · Dec 10

Next: #Precambrian #Earth with PhD student @mcolinmarvin.bsky.social, with "Zircon microtextures: A record of Earth's earliest surface environments" (EP43F-03, 146 C).

Th 2:30-2:40 pm.

Tiny scratches pack much info on first ~90% of Earth's history!

#AGU24

(3/10)

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Mathieu Lapôtre @marslogander.bsky.social · Dec 10

First stop: #Earth with PhD student Michael Hasson for " #Vegetation alters the migration trajectory of #meander bends"
(EP41E-1245, hall B-C).

Th 8:30 am-12:20 pm.

Cool implications for river evolution in the #Paleozoic!

#AGU24

(2/10)

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Mathieu Lapôtre @marslogander.bsky.social · Dec 10

#Rivers, #winds, #waves, and #impacts are all on the program for Stanford EPSP at #AGU24! Come along with us to explore #landscapes through #space (#Earth, #Moon, #Mars) and #time ( #Archean / #Hesperian to #future)

All times EST.

(1/10)

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Mathieu Lapôtre @marslogander.bsky.social · Feb 26

Last but not least, @stanforddoerr PhD student @mhasson7 will present a new depositional model for meandering #rivers that form in landscapes devoid of vegetation on Fr pm. Critical to deciphering rock record and paleoenvironments of the early #Earth and #Mars! EP56A-06 (6/6).

Mathieu Lapôtre @marslogander.bsky.social · Feb 26

Th pm, @stanforddoerr #SURGE student Emiliano Gonzalez will show how rock type influences sizes and distribution of boulders created by meteor impacts on the #Moon, and how they degrade through time, with implications for cratering mechanics and dating. P45A-04 (5/6)

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