Brenhin Keller

Graphic that says I'm supporting PRI today because it's where my type specimen is with a picture of a Vermicularia (snail) apex. The PRI logo is in the bottom right and text reads www.priweb.org/donate

This #givingtuesday please consider donating to the Paleontological Research Institution/Museum of the Earth

PRI is a major US fossil collection and education center
& has been struggling after a major donor was unable to fulfill a pledge but is almost out of the woods, any support helps!
🦑⚒️🧪🐌🐚

That's old!!

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!

Pyritised, metamorphosed, and faulted #Archean microbial mats from South Africa. I love the colours on this one. #geology #paleontology

A really nice alluvial fan

Here’s a really nice alluvial fan I thought you should see

It's kind of wild that the ultramafics are competent enough to make up one of the highest peaks in the region!

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....

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

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.

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

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

I'm hoping that's sarcastic and these don't exist?

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

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.

That's wild

That's with juliac I assume? Not too bad!

That sounds like a confusing choice

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.

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...

1/ An ongoing thread on the devastating M7.7 Mandalay (Myanmar) earthquake, 28 March 2025.

This GIS map is from USGS Pager.

#geographyteacher

We are assuming this was a planetary scientist traveling to the Lunar and Planetary Science Conference

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...

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...

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.

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.

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...

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

Coming soon to TidierFiles.jl for #JuliaLang: reading Google sheets as DataFrames.

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

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

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 😄

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

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):

Figure comparing automatic differentiation (AD) and automatic sparse differentiation (ASD). (a) Given a function f, AD backends return a function computing vector-Jacobian products (VJPs). (b) Standard AD computes Jacobians row-by-row by evaluating VJPs with all standard basis vectors. (c) ASD reduces the number of VJP evaluations by first detecting a sparsity pattern of non-zero values, coloring orthogonal rows in the pattern and simultaneously evaluating VJPs of orthogonal rows. The concepts shown in this figure directly translate to forward-mode, which computes Jacobians column-by-column instead of row-by-row.

You think Jacobian and Hessian matrices are prohibitively expensive to compute on your problem? Our latest preprint with @gdalle.bsky.social might change your mind!
arxiv.org/abs/2501.17737
🧵1/8

Nominations for the M. Lee Allison Award for excellence in Geoinformatics are open. This award is granted annually by GSA Geoinformatics and Data Science Division. Review of nominations will begin on March 1st, 2025. Please spread the word! Here is the nomination form: forms.office.com/r/CEBjb4kWZk

Fresh & dense picrite, fresh aphyric 'a'a, basalts with infilled vesicles, and basalts with sharp flow contacts. just a few of the #hawaiian lavas cored well below modern sea level on #IODP #exp389 are showing a surprising range of #volcanic textures... all in the first site we've examined thus far.

For any earth science grad students looking for a postdoc next year! ⚒️🧪