Brenhin Keller
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brenhinkeller.bsky.social
Brenhin Keller
@brenhinkeller.bsky.social
1.3K followers 810 following 130 posts
Assistant Prof. of Earth Sciences, Dartmouth College
Geochronology | Petrology | Earth History |
Computational Science | HPC | #julialang | he/they
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brenhinkeller.bsky.social
Brenhin Keller @brenhinkeller.bsky.social · Dec 22
New paper on glacial erosion rates and the Sadler effect that came out of a @dartmouthears.bsky.social grad seminar class just out now in Sci Adv! doi.org/10.1126/scia...
Limits to timescale dependence in erosion rates: Quantifying glacial and fluvial erosion across timescales
Globally, glacial erosion rates outpace fluvial, with limits to the biases introduced by measuring across different timescales.
doi.org
brenhinkeller.bsky.social
That's old!!
October 29, 2025 at 1:29 AM
Reposted by Brenhin Keller
dartmouthears.bsky.social
We are looking to hire a full-time tenure-track Assistant Professor in the general areas of stable isotope biogeochemistry and/or geobiology! For more information and to apply see apply.interfolio.com/176517 -- review begins November 15!
Apply - Interfolio {{$ctrl.$state.data.pageTitle}} - Apply - Interfolio
apply.interfolio.com
October 28, 2025 at 8:59 PM
Reposted by Brenhin Keller
geologyjohnson.bsky.social
Pyritised, metamorphosed, and faulted #Archean microbial mats from South Africa. I love the colours on this one. #geology #paleontology
Photo of a rock with alternative wrinkly dark green and light green layers. There is a layer in the middle composed of brass colored polygonal pyrite crystals. A white scale bar shows that the rock is about 2 cm wide.
October 18, 2025 at 9:07 PM
Reposted by Brenhin Keller
permafrostee.bsky.social
Here’s a really nice alluvial fan I thought you should see
A really nice alluvial fan
September 4, 2025 at 6:14 PM
brenhinkeller.bsky.social
It's kind of wild that the ultramafics are competent enough to make up one of the highest peaks in the region!
August 16, 2025 at 12:32 AM
brenhinkeller.bsky.social
Ah, that's probably the same ultramafics that make up Monte Disgrazia, just above/east of the roof contact of the Bergell pluton - doi.org/10.1029/97JB01510
Fossil crust‐to‐mantle transition, Val Malenco (Italian Alps)
An exhumed, undisturbed fossil lower crust to upper mantle section is preserved in Val Malenco, Italian Alps, and is now exposed along the boundary between Penninic and Austroalpine nappes. Lower-cru....
doi.org
August 15, 2025 at 7:17 PM
Reposted by Brenhin Keller
geophotographer.org
Check out these photos of the Tracy Arm Landslide to help get an idea of just how big it is.

📷 © Jacek Maselko and posted by AEC, taken at 3,500ft elevation on Tuesday, August 12th.

AEC page
earthquake.alaska.edu

AEC Facebook post
www.facebook.com/share/1Fzmxn...
🧪⚒️🌊
#alaska
#tsunami
#landslide
The image depicts a mountainous landscape with steep cliffs prominently visible in the foreground. The rock faces are textured with varying shades of gray, brown, and areas of green vegetation. A small body of water with a frothy surface lies at the base of the cliffs. In the background, a range of snow-capped mountains stretches across the horizon under a sky filled with thin, layered clouds. The overall scene has a rugged and expansive natural beauty. The image depicts a rugged mountain landscape featuring towering, snow-capped peaks under partly cloudy skies. The mountains are steep and rocky with patches of green vegetation on the lower slopes. A mixture of brown and gray rock is visible, contrasting with the white snow. At the base of the mountains lies a glacial area, showing large, sharp ice formations with a distinct blue tint. A small lake of muddy water is surrounded by chunks of ice. The foreground features green foothills. The overall setting is vast and remote, evoking a sense of untouched wilderness. The image depicts a mountainous landscape with steep, rocky peaks partially covered in snow. A glacier is visible in a valley between the mountains, flowing towards a body of water peppered with chunks of ice. The water is a mix of murky brown and icy blue, suggesting it is glacial runoff. The foreground is a contrast of vibrant green vegetation, displaying a dense forest at the bottom. The sky above is partly cloudy. The photo captures the natural beauty and ruggedness of the terrain. The image captures an aerial view of a vast glacial landscape. The foreground shows a rugged, uneven expanse of gray and white ice with visible crevasses, characteristic of a glacier. To the left, a wing of the aircraft is partially visible, indicating the perspective of the photo. Beyond the glacier, steep, rocky mountains rise dramatically, their surfaces marked with patches of green vegetation and some snow at the peaks. In the background, another glacier winds through a valley, bordered by more mountainous terrain. The sky is mostly clear, allowing sunlight to illuminate the scene.
August 14, 2025 at 9:35 PM
Reposted by Brenhin Keller
fossilsndcoffee.bsky.social
For Day50 of photoshopping @lastweektonight.com's John Oliver with fossils in the hopes that he saves the Paleontological Research Institution

Celebrating 90yrs of mollusk research at PRI! John is joined by a number of other H. sapiens who love science (and fun)-tag them all! 🧪🦑⚒️🐌 #fossils #savePRI
A case showing mollusk research at PRI including the logo, Ecphora, Turritellids, oysters, clams, and turrids. Text explains that PRI is one of the most important fossil collections in the US, especially for mollusks with well over 1 million mollusk specimens and 7 million total specimens in collections.
June 17, 2025 at 1:46 AM
brenhinkeller.bsky.social
I'm hoping that's sarcastic and these don't exist?
April 30, 2025 at 2:15 PM
Reposted by Brenhin Keller
clarkeocrinus.bsky.social
I sometimes take advantage of the analytical equipment at my real job. This is a Cambrian arthropod (probably not a Beckwithia) from the Wheeler shale of Utah. I used the XRF (X-ray fluorescence) to highlight iron and phosphorus. This is a 500 Ma digestive system.

#FossilFriday
April 18, 2025 at 9:56 PM
Reposted by Brenhin Keller
ljelkins.bsky.social
I am pleased to announce that my department (EAS at Nebraska) is hiring a teaching postdoc for AY 2025-2026 in the area of Earth Materials! I'm not on the committee but am spreading the word to my mineralogy/petrology networks on behalf of the committee. See ad for more details.
Postdoctoral Teaching Associate
The Department of Earth and Atmospheric Sciences (https://eas.unl.edu) at the University of Nebraska-Lincoln (UNL) has an opening for a Postdoctoral Teaching Associate in Earth Sciences. We are seekin...
employment.unl.edu
April 16, 2025 at 10:41 PM
brenhinkeller.bsky.social
That's wild
April 4, 2025 at 8:09 PM
brenhinkeller.bsky.social
That's with juliac I assume? Not too bad!
April 4, 2025 at 7:27 PM
brenhinkeller.bsky.social
That sounds like a confusing choice
April 4, 2025 at 7:21 PM
Reposted by Brenhin Keller
jeffgreene.bsky.social
Unsurprisingly, @tressiemcphd.bsky.social is spot-on in this analysis: “A.I.’s most revolutionary potential is helping experts apply their expertise better and faster. But for that to work, there has to be experts.”
www.nytimes.com/2025/03/29/o...
Opinion | Actually, A.I. Is Pretty Mid (Gift Article)
A.I. is just what we need in the post-fact era: less research and more predicting what we want to hear.
www.nytimes.com
March 29, 2025 at 11:30 AM
Reposted by Brenhin Keller
ahamill.bsky.social
1/ An ongoing thread on the devastating M7.7 Mandalay (Myanmar) earthquake, 28 March 2025.

This GIS map is from USGS Pager.

#geographyteacher
March 29, 2025 at 8:07 AM
Reposted by Brenhin Keller
planetdr.bsky.social
We are assuming this was a planetary scientist traveling to the Lunar and Planetary Science Conference
paulecohen.bsky.social Paul Cohen @paulecohen.bsky.social · Mar 19
Le Monde reporting that a French scientist traveling to Houston to attend a conference was denied entry to US after a search of his phone & computer revealed messages critical of Trump's science cuts, "which [says CPB] conveyed hatred of Trump & could be qualified as terrorism". Computer confiscated
March 19, 2025 at 9:12 PM
Reposted by Brenhin Keller
goco.bsky.social
Who’s guilty of the discrepancy between minerals and whole-rock chemistry in plutons? Melt extraction might be innocent—mineral reequilibration is likely the real culprit! Fresh out on Pi Day by me, Brenhin @brenhinkeller.bsky.social, & Changqian! doi.org/10.1029/2024...
Amphibole Compositions Record Cold Post‐Emplacement Reequilibration in Plutons
Melts predicted from mineral compositions in arc plutonic rocks do not match bulk compositions, a discrepancy absent in volcanic rocks Neither bulk crystallization nor melt extraction can fully e...
doi.org
March 14, 2025 at 8:03 PM
Reposted by Brenhin Keller
byscottdance.com
New: A NOAA lab in Hawaii that is connected to the longest-running observation of global greenhouse gas concentrations is slated for closure in August, according to a list of lease terminations Democratic members of Congress shared with @washingtonpost.com.
Trump moves to close government lab that tracks planet-warming pollution
The lab is connected to the Mauna Loa Observatory, where scientists gather data to produce the Keeling Curve, a chart on the daily status of atmospheric carbon dioxide concentrations.
www.washingtonpost.com
March 14, 2025 at 6:23 PM
Reposted by Brenhin Keller
fontb.bsky.social
Playing a bit with our WaterLily.jl #CFD #JuliaLang solver and homogeneous isotropic decaying turbulence 🌀 128^3 grid running on my local #GPU ⚡ visualizing in real-time with @makie.org
github.com/WaterLily-jl...
March 12, 2025 at 10:47 PM
brenhinkeller.bsky.social
Ah so it's in skyfeed and was just set to the maximum search time (seven days), though it looks like they do now have a "remember posts" option that one can add as an extra "block" so we can try that
February 14, 2025 at 7:10 AM
Reposted by Brenhin Keller
tidierjl.bsky.social
Coming soon to TidierFiles.jl for #JuliaLang: reading Google sheets as DataFrames.
February 9, 2025 at 4:53 AM
Reposted by Brenhin Keller
carlzimmer.com
National Science Foundation suspends salary payments, leaving researchers unable to pay their bills www.statnews.com/2025/01/30/t...
Story by @ericboodman.bsky.social
National Science Foundation suspends salary payments, leaving researchers unable to pay their bills
An NSF online payment system remained down after the federal funding freeze was lifted, leaving early-career scientists scrambling to pay bills
www.statnews.com
January 30, 2025 at 10:53 PM
brenhinkeller.bsky.social
Possibly apocryphal, but I remember hearing something along the lines that in the very early days Jeff & co at some point considered something more like this as the default syntax for Julia. Maybe not too shocking given that Sussman was on Jeff's thesis committee 😄
January 31, 2025 at 2:41 AM
brenhinkeller.bsky.social
One of my favorite Julia factoids is that in addition to LispSyntax.jl there's also a not-much-discussed built-in S-expresssion syntax for Julia which is normally only used as an alternate way of viewing Julia `Expr`s but can be hacked into a REPL mode in twenty-some lines (code in alt text):
to_expr(x) = x to_expr(t::Tuple) = Expr(to_expr.(t)...) lisparse(x) = to_expr(eval(Meta.parse(x))) function lispmode() printstyled("\nlisp> ", color=:magenta, bold=true) l = readline() # READ while l !== "(:exit)" try # So we don't get thrown out of the mode result = eval(lisparse(l)) # EVAL if isa(result, Expr) # PRINT (Meta.show_sexpr(result); println()) elseif isa(result, Tuple) Meta.show_sexpr(:($(result...),)); println() else display(result) end catch e display(e) end printstyled("\nlisp> ", color=:magenta, bold=true) l = readline() # READ end end
January 31, 2025 at 2:27 AM