Alfredo Martínez García

Deglacial stratification of the polar Southern Ocean | PNAS www.pnas.org/doi/10.1073/...

Ice shield in the Southern Ocean

Antarctic ice melt 🧊🌍 changed global ocean circulation. Ice-sheet melt temporarily intensified Southern Ocean stratification.
👉 tinyurl.com/rvasrrnv

#SouthernOcean #Antarctica #OceanCirculation #ClimateScience #PaleoClimate

Thanks to all our co-authors Yair Rosenthal, Daniel Sigman, and @amglab.bsky.social, host institutes @rutgersupress.bsky.social @marine.rutgers.edu @unisouthampton.bsky.social @mpic.de @whoi.edu @princeton.edu, and funders @snsf.ch @maxplanck.de NSF, IODP, and Rutgers

Climate change fuels the Great Atlantic Sargassum Belt - Nature Geoscience Our oceans are changing rapidly, with climate-driven shifts in circulation and nutrient cycles reshaping marine ecosystems in profound ways. One of the most visible and disruptive outcomes is the expl...

www.nature.com/articles/s41... 🧪

Tightening the Sargassum belt - Nature Geoscience A belt of seaweed has formed across the tropical Atlantic nearly every year since 2011, despite reduction in its extent elsewhere. The causes of this growth are now coming into clearer focus.

www.nature.com/articles/s41... 🧪

Cosmic dust reveals dynamic shifts in central Arctic sea-ice coverage over the past 30,000 years Arctic sea-ice loss affects biological productivity, sustenance in coastal communities, and geopolitics. Forecasting these impacts requires mechanistic understanding of how Arctic sea ice responds to ...

Huge paper for the Arctic Ocean published today in @science.org - a new 30,000 year history of Arctic Ocean sea-ice cover reconstructed from the accumulation of cosmic dust-derived helium-3! www.science.org/doi/10.1126/... (1/n)

Equatorial upwelling of phosphorus drives Atlantic N2 fixation and Sargassum blooms - Nature Geoscience High near-surface nitrogen-fixation rates that promoted the recent growth of the Great Atlantic Sargassum Belt were tied to greater upwelling of phosphorus from the equatorial Atlantic, according to c...

Check out our latest work, led by Jon Jung, Ph.D. student in the @amglab.bsky.social at @mpic.de:

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

Here we show that the supply of excess phosphorous from accounts for the majority of observed Sargassum variability since 2011.

🌊 🧪 #Paleosky #CoralReefs

Persistent eastern equatorial Pacific Ocean upwelling since the warm Pliocene Upwelling generates a nutrient-rich “cold tongue” in the eastern equatorial Pacific Ocean (EEP), with impacts on global climate, oceanic biological productivity, and the carbon cycle. The cold tongue ...

Today, we published a study long in the making on how upper and subsurface tropical Pacific waters responded (and maybe will adjust) to warmer global climate. Here’s the story of how we got here after 15 years. many authors but shout out @jfarmersalmanac.bsky.social
🌊
www.science.org/doi/10.1126/...

Origins of the Nitrate 15N Depletion in the Mediterranean Sea Basin-wide depth profiles of nitrate δ15N and δ18O indicate a supply of low-δ15N N to the Mediterranean Sea Nitrate δ15N can be explained by modest rates of N2 fixation and/or anthropogenic N dep...

Another cool paper coming out of @amglab.bsky.social. Led by Tanja Wald, here we present basin-wide profiles of Mediterranean nitrate N/O isotopes, and show that this distribution can be explained by a combination of nitrogen fixation and anthropogenic nitrogen deposition: dx.doi.org/10.1029/2023...

Early Pliocene Shoaling of the Central American Seaway Reconstructed From Foraminifera‐Bound Nitrogen and Oxygen Isotopes Foraminifera-bound nitrogen isotopes trace the early Pliocene restriction of nutrient exchange across the Central American Seaway Geochemical data indicate four phases of seaway shoaling between ...

Just published open-access in @agu.org's Paleo Paleo: A new foraminifera-bound nitrogen isotope perspective on one of geology's evergreen mysteries: The history of the Central American Seaway agupubs.onlinelibrary.wiley.com/doi/full/10.... (1/a few)...

Recurrent humid phases in Arabia over the past 8 million years - Nature A climatic record from desert speleothems shows that the central Arabian interior experienced recurrent humid intervals over the past 8 million years, which likely facilitated mammalian dispersals bet...

(1/13) A thread on our new paper just published in Nature, ‘Recurrent humid phases in Arabia over the past 8 million years’. www.nature.com/articles/s41...

Reviews and syntheses: Review of proxies for low-oxygen paleoceanographic reconstructions Abstract. A growing body of observations has revealed rapid changes in both the total inventory and the distribution of marine oxygen over the latter half of the 20th century, leading to increased int...

A mammoth effort from all involved. Great to see this published. bg.copernicus.org/articles/22/...

El esmalte dental de los australopitecos demuestra que fueron vegetarianos Los australopitecos se alimentaban esencialmente de vegetales. Quizá comían carne de forma ocasional, pero lo hacían en cantidades pequeñas. Es la conclusión a la

www.lavanguardia.com/ciencia/2025...

Rising infections from a dusty devil, and nailing down when our ancestors became meat eaters On this week’s show: Climate change may be driving an expansion of Valley fever, a deadly fungal infection spread by desert-loving spores, and a look at <em>Australopithecus</em>’s diet 3 million year...

Listen to Tina Lüdecke explaining our latest @science.org
paper investigating the diet of our ancient hominin relatives Australopithecus on the Science Podcast:

www.science.org/content/podc...

Meat was not on the menu for human ancestor Australopithecus The incorporation of meat into the diet was a milestone for the human evolutionary lineage, a potential catalyst for advances such as increased brain size. But scientists have struggled to determine when meat consumption began and who did it.

www.reuters.com/science/meat...

Discovery of Laacher See eruption in speleothem record synchronizes Greenland and central European Late Glacial climate change A volcanic sulfur spike links the Laacher See eruption to Greenland ice cores and synchronizes the timelines to European records.

Excited to share our latest research published in @science.org #ScienceAdvances! 🎉
We've discovered the Laacher See eruption 🌋 in a speleothem from Germany, which allows to synchronize European and Greenland Late Glacial climate change.

Read more: www.science.org/doi/10.1126/...

A Thread ⬇️⬇️ 1/n

Australopithecus at Sterkfontein did not consume substantial mammalian meat Incorporation of animal-based foods into early hominin diets has been hypothesized to be a major catalyst of many important evolutionary events, including brain expansion. However, direct evidence of ...

Hot off the press, in a study published today in Science, we show that Australopithecus did not consume
substantial mammalian meat
www.science.org/doi/10.1126/...

You can find a link for free access to our latest Science paper (Decadal oscillations in the ocean’s largest oxygen-deficient zone) in my website (www.theamglab.com/publications)

The largest oxygen-poor region of the ocean is more variable than previously thought Analysis of nitrogen isotope ratio in skeletons shows strong decadal oscillations in the size of the world's largest oxygen-deficient zone (ODZ) over the last 80 years. These findings imply that this ...

www.mpic.de/5621752/larg...

Congrats to @climatereefs.bsky.social colleague Nic Duprey of the @amglab.bsky.social on his publication in Science

Lots of cool science on corals coming out of the @amglab.bsky.social at the moment, with #SPP2299 colleagues involved

More cool science on corals coming out of the @amglab.bsky.social at the moment, with #SPP2299 colleagues involved

Large‐Volume Injection and Assessment of Reference Standards for n‐Alkane δD and δ13C Analysis via Gas Chromatography Isotope Ratio Mass Spectrometry Rationale Compound-specific stable isotope analysis of hydrogen (δD) and carbon (δ13C) in organic compounds is a valuable tool in biogeochemical research. A key limitation of this method is the rela.....

Ever wanted to get just a little bit more out of your lipid extracts when measuring compound specific isotopes?

If yes, here's a new paper that might be of interested to you:

analyticalsciencejournals.onlinelibrary.wiley.com/doi/10.1002/...

with @amglab.bsky.social

Decadal oscillations in the ocean’s largest oxygen-deficient zone The impact of global warming on the ocean’s oxygen-deficient zones (ODZs) is uncertain, partly because of a lack of data on past changes. We report monthly resolved records of coral skeleton–bound nit...

www.science.org/doi/10.1126/...

Large‐Volume Injection and Assessment of Reference Standards for n‐Alkane δD and δ13C Analysis via Gas Chromatography Isotope Ratio Mass Spectrometry Rationale Compound-specific stable isotope analysis of hydrogen (δD) and carbon (δ13C) in organic compounds is a valuable tool in biogeochemical research. A key limitation of this method is the rela...

analyticalsciencejournals.onlinelibrary.wiley.com/doi/10.1002/...

Descubierta una de las primeras amistades entre especies diferentes La simbiosis entre corales y algas, observada en arrecifes fósiles de 385 millones de años, permitió una explosión de vida que da de comer a 500 millones de personas

elpais.com/ciencia/2024...

Coral photosymbiosis on Mid-Devonian reefs - Nature Nitrogen isotope evidence of Mid-Devonian photosymbiotic associations in certain types of corals suggests that&nbsp;autotrophic and heterotrophic corals co-existed on extinct reefs, as today, but in w...

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