Geochemistry – Geobites

July 16, 2024July 29, 2024

Podemos encontrar microorganismos del mar profundo reposando en tumbas que ellos mismos construyeron

Imagen principal: Alvin – un vehículo de ocupación humana (VOH) sumergible diseñado para permitir la recolección de datos a profundidades hasta 6,500 m por debajo de la superficie del océano. Imágen principal cortesía de John Magyar, Caltech.

Artículo: Precipitación de sílice inducida por microorganismos en un consorcio de oxidadores anaeróbicos de metano e implicaciones para la preservación de fósiles microbianos

Autores: Daniela Osorio-Rodriguez, Kyle S. Metcalfe, Shawn E. McGlynn, Hang Yu, Anne E. Dekas, Mark Ellisman, Tom Deerinck, Ludmilla Aristilde, John P. Grotzinger, and Victoria J. Orphan

Tal vez un fin de semana en tu vida, te encuentres apilado en un vehículo todoterreno a las 6 de la mañana con otros siete estudiantes, registrando intermitentemente el dron de un profesor de geología demasiado entusiasta cuya clase tomaste para llenar un requisito de tu programa. Si es así, en ese vehículo con certeza se pronunció la proclamación “el presente es la clave del pasado”. Un estudio reciente conducido por Daniela Osorio-Rodriguez y colaboradores epitomiza el poder de esas palabras.

May 24, 2024July 8, 2024

We may find deep-sea microbes resting in tombs they built themselves

Featured Image: Alvin – a submersible Human Occupancy Vehicle (HOV) designed to allow data collection at depths up to 6,500 m below the ocean surface. Featured image courtesy of John Magyar, Caltech.

Paper: Microbially induced precipitation of silica by anaerobic methane-oxidizing consortia and implications for microbial fossil preservation

Authors: Daniela Osorio-Rodriguez, Kyle S. Metcalfe, Shawn E. McGlynn, Hang Yu, Anne E. Dekas, Mark Ellisman, Tom Deerinck, Ludmilla Aristilde, John P. Grotzinger, and Victoria J. Orphan

Maybe one weekend in your life, you found yourself piling into an SUV at 6 AM with seven other students, intermittently registering the drone of an overenthusiastic geology professor whose course you took to fulfill a degree requirement. If so, in that vehicle, the proclamation that “the present is the key to the past” was certainly uttered. A recent study conducted by Daniela Osorio-Rodriguez and collaborators epitomizes the power of those words.

February 7, 2023February 7, 2023

Microscopic Miners: How invisible forces create tropical caves

Featured Image: Scientist Ceth Parker moving through a passageway within an iron formation cave. Photo courtesy of the University of Akron.

Paper: Enhanced terrestrial Fe(II) mobilization identified through a novel mechanism of microbially driven cave formation in Fe(III)-rich rocks

Authors: Ceth W. Parker, John M. Senko, Augusto S. Auler, Ira D. Sasowsky, Frederik Schulz, Tanja Woyke, Hazel A. Barton

Consider this: microscopic creatures literally moving tons of rock before your very eyes. It seems too fantastical, but maybe not if you’re in the Brazilian tropics. In new work, scientists have detailed these stealthy and microscopic processes, naming a new cave generation pathway called exothenic biospeleogenesis, or “behind-wall life-created” caves.

August 25, 2022August 31, 2022

One Sailors’ Legend Down, Many More To Go – Multiple Milky Sea Events Detected by Satellite

Processed satellite images showing a milky sea event in Java, 2019.

Featured image: Processed satellite images showing a milky sea event and its components in Java, 2019. From Miller et al, 2021 (figure 5).

Paper: Miller, S.D., Haddock, S.H.D., Straka, W.C. et al. Honing in on bioluminescent milky seas from space. Sci Rep 11, 15443 (2021). https://doi.org/10.1038/s41598-021-94823-z

Sailors see a lot of, well, stuff while they’re far from land. And they’re known for telling unbelievable tales, some of which later turn out to be more or less true. Milky seas are one of those: a horizon-to-horizon sea that glows white like the snow in the moonlight. In a 2021 paper, Dr. Steven Miller of Colorado State University and colleagues used satellites to look for these systems in hopes of understanding how and why these glowing patches form.

The first satellite detection of a milky sea event was also the work of Dr. Miller, in a 2005 paper that detected just a single event by combing ships’ logs and satellite archives from the preceding decade. Now, Miller’s research team has refined the algorithm that he’d previously developed for modern satellite records. Today’s satellite technology is better able to ‘see’ these events due to higher resolution of their images and can pick out the bioluminescent glow of microbes in the ocean better than the last generation of satellites.

January 27, 2022January 27, 2022

The surprising effects rivers have on our atmosphere

Featured Image: Rio Bermejo meeting up with the Paraguay River, on the boarder of Formosa and Chaco Provinces. Image by Mapio. Used with permision.

Paper: Fluvial organic carbon cycling regulated by sediment transit time and mineral protection

Authors: Marisa Repasch, Joel S. Scheingross, Niels Hovius, Maarten Lupker, Hella Wittmann, Negar Haghipour, Darren R. Gröcke, Oscar Orfeo, Timothy I. Eglinton, and Dirk Sachse

In our current era of rapid climate change, it is critical we understand how every aspect of the Earth system affects carbon cycling. New work by Marisa Repasch and colleagues shows that rivers, under the right conditions, might be able to sequester more carbon in the sediments than released into the atmosphere. However, these findings may reveal how human impacts to rivers will likely increase the amount of carbon released to the atmosphere.

December 14, 2021December 14, 2021

Metal-Eating Microbes Who Breathe Methane

Featured Image: Murky pond in Alaska with “rusty” iron-filled sediments. Image courtesy Jessica Buser. Used with permission.

Paper: Sulfate- and iron-dependent anaerobic methane oxidation occurring side-by-side in freshwater lake sediment

Authors: Alina Mostovaya, Michael Wind-Hansen, Paul Rousteau, Laura A. Bristow, Bo Thamdrup

The table has been set and the food is all prepared. But this is no ordinary dinner party, it’s a microbe party! The guests sit down and proceed to dig into the main course; sulfur, rusty iron, and methane. Curiously, the guests are feeding each other, not themselves! This image seems pretty weird to us humans, but it’s a delight to these microbes. This collaborative method of eating occurs in pond and lake mud all around the world. In a new study, Mostovaya and colleagues describe one such feast in Danish Lake Ørn, that is not only collaborative but may mitigate climate change.

October 12, 2021October 12, 2021

Ancient trees tell the story of modern climate change

Featured Image: Larch trees. Image courtesy North Cascades National Park, used with permission.

Paper: Spring arctic oscillation as a trigger of summer drought in Siberian subarctic over the past 1494 years

Authors: Olga V. Churakova Sidorova, Rolf T. W. Siegwolf, Marina V. Fonti, Eugene A. Vaganov, Matthias Saurer

Seemingly straight out of a fairytale, ancient trees are able to convey details about Earth’s complex history to the scientists willing and able to listen. Deep in the Siberian Arctic lie the secrets of past weather events, ocean currents, and droughts that occurred thousands of years ago, locked away in petrified wood and in the oldest living larch trees. We often hear in the news how the Siberian forest is victim to extreme drought and fire—something that is new as of the recent century. But how “new” are these events, and what exactly is perpetuating this new cycle?

June 17, 2021June 17, 2021

Mercury on the Move

Featured image: Gravel and rocks crushed by the Greenland Ice Sheet. Image courtesy PennStateNews, used with permission.

Paper: Large subglacial source of mercury from the southwestern margin of the Greenland Ice Sheet

Authors: Jon R. Hawkings, Benjamin S. Linhoff, Jemma L. Wadham, Marek Stibal, Carl H. Lamborg, Gregory T. Carling, Guillaume Lamarche-Gagnon, Tyler J. Kohler, Rachael Ward, Katharine R. Hendry, Lukáš Falteisek, Anne M. Kellerman, Karen A. Cameron, Jade E. Hatton, Sarah Tingey, Amy D. Holt, Petra Vinšová, Stefan Hofer, Marie Bulínová, Tomáš Větrovský, Lorenz Meire, Robert G. M. Spencer

The Greenland Ice Sheet is melting at an astounding rate as our planet continues to warm. Mercury levels in the glacial meltwater traveling into the ocean are the highest levels ever measured in natural systems and rival heavily polluted rivers in Asia. By measuring and tracing mercury in the meltwater, Hawkings and coworkers estimated that the Greenland Ice Sheet contributes up to 10% of all mercury found in Earth’s Oceans today. Where is this mercury coming from within the Greenland Ice Sheet? It is not actually coming from the ice itself, but rather the rocks that have been crushed under the immense weight of the Ice Sheet over thousands of years.

May 6, 2021May 6, 2021

Antarctic seafloor oxygen is diminishing–and glaciers may be to blame

Featured Image: Iceberg floating through thin sea ice. Image courtesy NASA ICE, used with permission.

Paper: Glacial melt disturbance shifts community metabolism of an Antarctic seafloor ecosystem from net autotrophy to heterotrophy

Authors: Ulrike Braeckman, Francesca Pasotti, Ralf Hoffmann, Susana Vázquez, Angela Wulff, Irene R. Schloss, Ulrike Falk, Dolores Deregibus, Nene Lefaible, Anders Torstensson, Adil Al-Handal, Frank Wenzhöfer, Ann Vanreusel

Nothing compares to the ethereal beauty of a clear lake. Looking down, you can see a whole world flourishing below: plants, fish, and critters. Compare that to a cloudy, or turbid, lake and suddenly you may feel very small, worried about what’s lurking beneath you. New research shows that the Antarctic ocean is transitioning from clear to turbid water, with big implications for ocean ecosystems.

April 28, 2021April 28, 2021

Rust to the Rescue?

Featured Image: Shewanella putrefaciens CN-32 (a microbe capable of eating iron) on hematite (a rock containing iron). Image courtesy Environmental Molecular Sciences Laboratory (EMSL). Used with permission.

Paper: Organic matter mineralization in modern and ancient ferruginous sediments

Authors: André Friese, Kohen Bauer, Clemens Glombitza, Luis Ordoñez, Daniel Ariztegui Verena B. Heuer, Aurèle Vuillemin, Cynthia Henny, Sulung Nomosatryo, Rachel Simister Dirk Wagner, Satria Bijaksana, Hendrik Vogel, Martin Melles, James M. Russell, Sean A. Crowe, Jens Kallmeyer

Just as a crow may use a rock to crack a nut, certain microbes can use solid iron to crack open methane. This consumption limits the amount of methane lost from lakes into the atmosphere, making it a crucial process in mitigating production of greenhouse gasses. These microbes are abundant in freshwater sediments, and their specialized mechanism for cracking open methane is most likely one of the oldest metabolisms on Earth, providing a modern-day window into the past.