Featured image: Example of the rock type Pegmatite. Here, crystals of the mineral tourmaline (light-dark green color), and crystals of the mineral lepidolite (pink-purple color) can be seen, sourced from Wikipedia. This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.
Paper: Episodes of fast crystal growth in pegmatites
Authors: Patrick R. Phelps, Cin-Ty A. Lee, Douglas M. Morton
Anyone who has ever wandered along a pebble-ridden beach or a mountainous trail has likely picked up a rock or two, and maybe these rocks contained an array of different crystals (see image above). Perhaps these rocks then skipped along the surface of a still lake, or made their way into the pockets of a snack-ridden backpack, either to never be seen again or to be added to an ever-growing rock collection. Yet, these little pieces of Earth’s history have the potential to do so much more. With the right tools, the crystals within these rocks can be used to inform us of the geological processes that have shaped our planet Earth.
Continue reading “Cooking up crystals in record time”
Featured image: an aerial photograph of the Capitolias/Beit-Ras theater, courtesy of the Aerial Photographic Archive of Archaeology in the Middle East (APAAME), CC-BY-NC-ND 2.0
Paper: Two inferred antique earthquake phases recorded in the Roman theater of Beit-Ras/Capitolias (Jordan)
Authors: M. Al-Tawalbeh, R. Jaradat, K. Al-Bashaireh, A. Al-Rawabdeh, A. Gharaibeh, B. Khrisat, and M. Kázmér
One of the biggest questions in earthquake seismology is whether we can see into the future, to forecast seismic activity based on what we know about faults and how they behave. We’re about as likely to accurately predict earthquakes as we are to see the future in a crystal ball, but one way we can improve our forecasts of seismic hazard actually involves looking in the other direction: back into the past.
Continue reading “Shaken, rattled, and rolled”
Paper: Unraveling biogeochemical phosphorus dynamics in hyperarid Mars‐analogue soils using stable oxygen isotopes in phosphate
Authors: Jianxun Shen, Andrew C. Smith, Mark W. Claire, Aubrey L. Zerkle
Many geologists believe that ancient Mars, with its warmer temperatures and water-rich environment, may have been home to life. To test this hypothesis, astrobiologists must find signifiers of life that can survive the billions of years of hyperaridity experienced on the Martian surface. One such method could be identifying biotic alteration of the geochemical cycling of phosphorus, as was highly publicized during the recent discovery of phosphine in the atmosphere of Venus. Researchers have taken the first step in this search by characterizing biological phosphorus cycling in the analog environment of the Atacama Desert – an endeavor that has applied novel techniques in chemistry to provide insights about the movement of phosphorus in arid environments.
Continue reading “To P, not to P? That is (an oversimplification of) the biogeochemical question—”
Paper: High-latitude biomes and rock weathering mediate climate-carbon cycle feedbacks on eccentricity timescales.
Authors: David De Vleeschower, Anna Joy Drury, Maximilian Vahlenkamp, Fiona Rochholz, Diederik Liebrand & Heiko Pälike
Featured image: Benthic foraminifera collected from the North Sea in 2011. Image courtesy of Hans Hillewaert, licensed under CC BY-SA 4.0
Faced with a rapidly warming world, we all have the same questions on our collective minds: how will climate change restructure Earth and what can we do to adapt to those changes? One thing we do know is that the climate is intimately connected to the carbon cycle. When large amounts of carbon get moved between reservoirs (on land and in the ocean and atmosphere), changes in climate ensue. Currently, carbon stored on land is being moved to the atmosphere through anthropogenic CO2 emissions, causing global warming and its various cascading effects. What’s more, looking back in Earth’s history, researchers have established that moving carbon from the atmosphere to the ocean, or back onto land, has had a cooling effect. Just this past year, researchers from the University of Southampton investigated several factors affecting past carbon-climate connections, offering new understandings that could help address climate action moving forward.
Continue reading “It’s complicated; deciphering mixed signals of the carbon-climate relationship in Earth’s past”
Featured Image: Plumes of muddy, sediment-laden water at the Chesapeake Bay Bridge near Annapolis, MD. Photo courtesy of Jane Thomas/ IAN, UMCES.
Paper: Seabed Resuspension in the Chesapeake Bay: Implications for Biogeochemical Cycling and Hypoxia
Authors: Julia Moriarty, Marjorie Friedrichs, Courtney Harris
A memorable feature of the Chesapeake Bay, the largest estuary in the USA, is that the water is very murky and looks like chocolate milk. Former Senator Bernie Fowler has conducted public “wade-ins” over the past 50 years in one of the Bay’s tributaries, seeing how deep the water is before he can no longer see his white tennis shoes, and let’s just say it is never very deep. This is because of the high concentrations of sediment, or small particles of sand and organic material, in the water. Besides making it harder for seagrasses to grow and serving as food for the economically-important oyster, sediment impacts the biological processes that determine how much oxygen and nutrients are available in the water for algae and fish.
Continue reading “Muddy waters lead to decreased oxygen in Chesapeake Bay”
Featured Image: Small headwater stream in Oregon’s Mountains. Image courtesy Jessica Buser-Young, used with permission.
Paper: The River Continuum Concept
Authors: Robin L. Vannote, G. Wayne Minshall, Kenneth W. Cummins, James R. Sedell, Colbert E. Cushing
Perhaps last time you went for a hike, you stumbled upon a burbling spring pushing its way up through the leaf litter after a heavy rainfall, creating a tiny rivulet of water crisscrossing over your path before plunging back into the forest. What a find! Excitedly, you squatted down and gently uncovered the spring to notice gnats lazily floating away, some nearby fruiting mushrooms, and great clumps of decomposing twigs and leaves which you assume harbor uncountable numbers of microorganisms. This unique little ecosystem is profiting from the nutrients and water being pushed from the ground, using the opportunity to have a feast. But what happens to the nutrients and carbon that gets past these plants and animals?
Continue reading “Mosaics of Life Along a River”
Paper: Astronomical context of solar system formation from molybdenum isotopes in meteorite inclusions.
Featured image: Artistic impression of the protoplanetary disk. Image used with permission from Wikipedia (A. Angelich).
Authors: Gregory A. Brennecka, Christoph Burkhardt, Gerrit Budde, Thomas S. Kruijer, Francis Nimmo, Thorsten Kleine.
If you ask a cosmochemist what the oldest objects in the solar system are, they will swiftly answer the Calcium Aluminium Inclusions (CAIs), a small light-coloured inclusion within primitive meteorites known as Chondrites (see figure 2C). However, if you ask what event in the solar system evolution CAIs correspond to, it is a more challenging question. Previously, CAI formation was associated with the various evolutionary stages of our Sun. However, as the timescale of evolution of Sun, calculated to be around 1 million years by observing Sun like stars, is longer than the CAI forming period (~ 40,000 – 200,000 years), the association between CAI formation and the early stages of our Sun is not always clear. In a quest to put the CAI formation in an astronomical context, a recent study from Brennecka et al. analysed CAIs present within various Carbonaceous chondrite meteorites and linked the CAI formation to a specific stage in the Sun’s evolution.
Continue reading “Capturing Early Sun within meteorite inclusions”
Antarctic Krill under a microscope. Photo courtesy of Uwe Kils, CC-BY-SA 3.0
Paper: Manno et al. (2020)
The transfer of carbon from the surface ocean to the deep ocean, or carbon export, can strongly influence climate. The main pathway of carbon export in the ocean is through sinking particles, also known as the biological carbon pump. These sinking particles can include plankton biomass, aggregates of cells, and zooplankton feces and molts. Understanding what contributes to carbon export is important in understanding how this may change as temperatures warm due to climate change.
A recent study by Manno et al. found that Antarctic krill in the Southern Ocean may play a significant role in transporting carbon to the deep ocean through their carcasses, fecal material, and most notably their molts, or shedding of their shells. Exoskeletons are not only an important vehicle for carbon export but also provide food to animals living on the seafloor. This is the first study to investigate the contribution of krill molts to carbon export in the Southern Ocean.
Continue reading “Antarctic krill and their role in ocean carbon cycling”
Paper: Lightning-induced weathering of Cascadian volcanic peaks
Authors: Jonathan M. Castro, Franziska Keller, Yves Feisel, Pierre Lanari, Christoph Helo, Sebastian P. Mueller, C. Ian Schipper, Chad Thomas
The bright flashes followed by the loud thunderclaps of large storms are inherently transient, but a recent study by Castro et al proposes a new approach to investigating the history of storm activity and extreme weather events on Earth: through fossilized lightning strikes, or fulgurites.
Continue reading “When Lightning Strikes! Fulgurite Formation and Earth’s Weather”
Featured image: The Nirgal Vallis river valley on Mars as seen by the HRSC Camera onboard the European Space Agency’s Mars Express mission. Image credit: ESA/DLR/FU Berlin.
Paper: Valley formation on early Mars by subglacial and fluvial erosion.
Authors: Anna Grau Galofre, A. Mark Jellinek & Gordon R. Osinski.
“Some say the world will end in fire/ Some say in ice” begins the famous poem by Robert Frost. But what about how worlds begin? For years the theory of a “warm and wet” early Mars has been the conventional explanation for the vast valley networks formed billions of years ago that we can see on the surface today. Now, a new study suggests that at least some of these valleys could have formed under colossal ice sheets, in a distinctly more icy world.
Continue reading “How did valleys form on early Mars? Some say in ice…”