Explanipedia

Geochemical Phosphorus Sequestration in Tundra Soils Impedes Delivery of Bioavailable Phosphorus to the Kuparuk River, Alaska, USA: Implications for the Broader Arctic Region Open

Frederick W. Sutor, Eric D. Roy, Andrew W. Schroth, Alexander B. Michaud, David Emerson , et al. · 2025

Long‐term river monitoring of the Kuparuk River (North Slope, Alaska, USA) confirms significant increases in solutes that are indicative of active layer thickening due to thawing permafrost. However, there is no evidence of an increase in …

Feeding incremental amounts of the red seaweed Chondrus crispus: Effects on production performance, methane emissions, nutrient utilization, and ruminal and iodine metabolism in dairy cows Open

D.C. Reyes, João Paulo Sacramento, Charlotte T. C. Quigley, Benjamin S. Twining, Alexander B. Michaud , et al. · 2025

We investigated the effects of feeding incremental amounts (0%, 3%, and 6% of diet DM) of the red seaweed Chondrus crispus on DMI, milk yield and milk components, enteric CH₄ emissions, nutrient utilization, ruminal fermentation…

Dynamic subglacial meltwater history archived in Antarctic subglacial lake sediments Open

Timothy D. Campbell, Mark Skidmore, Molly O. Patterson, John E. Dore, David M. Harwood , et al. · 2025

There is a paucity of records on decadal to millennial scales archiving the evolution of the Antarctic subglacial hydrologic system, leaving a gap in our knowledge of the links between meltwater drainage and ice behavior. We employed a sui…

Phosphorus Interactions with Iron in Undisturbed and Disturbed Arctic Tundra Ecosystems Open

Matthew Berens, Alexander B. Michaud, Erin VanderJeugdt, Imtiaz Miah, Frederick W. Sutor , et al. · 2024

Phosphorus (P) limitation often constrains biological processes in Arctic tundra ecosystems. Although adsorption to soil minerals may limit P bioavailability and export from soils into aquatic systems, the contribution of mineral phases to…

A Cost Model for Ocean Iron Fertilization as a Means of Carbon Dioxide Removal That Compares Ship‐ and Aerial‐Based Delivery, and Estimates Verification Costs Open

David Emerson, Laura E. Sofen, Alexander B. Michaud, Stephen D. Archer, Benjamin S. Twining · 2024

We present a cost model for implementing a deployment scale effort for conducting ocean iron fertilization (OIF) for marine‐based carbon dioxide removal (CDR). The model incorporates basic oceanographic parameters critical for estimating t…

Trace element, rare earth element and trace carbon compounds in Subglacial Lake Whillans, West Antarctica Open

Clara Turetta, Elena Barbaro, Mark Skidmore, Andrea Gambaro, Alexander B. Michaud , et al. · 2023

Whillans Subglacial Lake (SLW) lies beneath 801 m of ice in the lower portion of the Whillans Ice Stream (WIS) in West Antarctica and is part of an extensive and active subglacial drainage network. Here, the geochemical characterization of…

Sediment oxygen consumption in <span>Antarctic</span> subglacial environments Open

Alexander B. Michaud, John C. Priscu · 2023

Oxygen consumption in aquatic sediments is an indicator of overall biological activity of the ecosystem. As such, rates of sedimentary oxygen utilization are well documented for much of the open oceans and freshwater lakes. However, there …

A cost model for ocean iron fertilization as a means of carbon dioxide removal that compares ship- and aerial-based delivery, and estimates verification costs. Open

David Emerson, Alexander B. Michaud, Stephen Archer, Laura Sofen, Benjamin S. Twining · 2023

This paper presents a cost model for implementing a deployment scale effort for conducting ocean iron fertilization (OIF) for marine-based carbon dioxide removal (CDR). The model incorporates basic oceanographic parameters critical for est…

Constraints on the Timing and Extent of Deglacial Grounding Line Retreat in West Antarctica Open

Ryan A. Venturelli, Brenna Boehman, Christina Davis, Jon Hawkings, Sarah Ellen Johnston , et al. · 2023

Projections of Antarctica's contribution to future sea level rise are associated with significant uncertainty, in part because the observational record is too short to capture long‐term processes necessary to estimate ice mass changes over…

The life and death of a subglacial lake in West Antarctica Open

Matthew R. Siegfried, Ryan A. Venturelli, Molly O. Patterson, William D. Arnuk, Timothy D. Campbell , et al. · 2023

Over the past 50 years, the discovery and initial investigation of subglacial lakes in Antarctica have highlighted the paleoglaciological information that may be recorded in sediments at their beds. In December 2018, we accessed Mercer Sub…

Data for Siegfried*, Venturelli*, et al., 2023, Geology Open

Matthew R. Siegfried, Ryan A. Venturelli, Molly O. Patterson, William D. Arnuk, Timothy D. Campbell , et al. · 2023

Datasets used in Siegfried*, Venturelli*, et al. (2023). The life and death of a subglacial lake in West Antarctica, Geology, doi: 10.1130/G50995.1. See top-level readme.md file for more information about the types of data and dat…

Data for Siegfried*, Venturelli*, et al., 2023, Geology Open

Matthew R. Siegfried, Ryan A. Venturelli, Molly O. Patterson, William D. Arnuk, Timothy D. Campbell , et al. · 2023

Datasets used in Siegfried*, Venturelli*, et al. (2023). The life and death of a subglacial lake in West Antarctica, Geology, doi: 10.1130/G50995.1. See top-level readme.md file for more information about the types of data and dat…

Biogeochemical and historical drivers of microbial community composition and structure in sediments from Mercer Subglacial Lake, West Antarctica Open

Christina Davis, Ryan A. Venturelli, Alexander B. Michaud, Jon Hawkings, Amanda M. Achberger , et al. · 2023

Ice streams that flow into Ross Ice Shelf are underlain by water-saturated sediments, a dynamic hydrological system, and subglacial lakes that intermittently discharge water downstream across grounding zones of West Antarctic Ice Sheet (WA…

Millennial scale marine incursion into an isolated environment fuels a contemporary subglacial microbial community beneath the West Antarctic Ice Sheet Open

Ryan A. Venturelli, B. E. Rosenheim, Christina Davis, Alexander B. Michaud, Brenna Boehman , et al. · 2023

Comment on tc-2022-68 Open

Alexander B. Michaud · 2022

Abstract. Glaciers and ice sheets possess layers of basal ice characterized by high amounts of entrained debris that can serve as sources of nutrients and organic matter, providing habitat for microorganisms adapted to the…

A dynamic saline groundwater system mapped beneath an Antarctic ice stream Open

Chloe Gustafson, Kerry Key, Matthew R. Siegfried, J. Paul Winberry, H. A. Fricker , et al. · 2022

Antarctica’s fast-flowing ice streams drain the ice sheet, with their velocity modulated by subglacial water systems. Current knowledge of these water systems is limited to the shallow portions near the ice-bed interface, but hypothesized …

Tight benthic-pelagic coupling drives seasonal and interannual changes in iron‑sulfur cycling in Arctic fjord sediments (Kongsfjorden, Svalbard) Open

Lisa C. Herbert, Alexander B. Michaud, Katja Laufer, Clara J. M. Hoppe, Qingzhi Zhu , et al. · 2021

Scientific access into Mercer Subglacial Lake: scientific objectives, drilling operations and initial observations Open

John C. Priscu, Jonas Kalin, John R. Winans, Timothy D. Campbell, Matthew R. Siegfried , et al. · 2021

The Subglacial Antarctic Lakes Scientific Access (SALSA) Project accessed Mercer Subglacial Lake using environmentally clean hot-water drilling to examine interactions among ice, water, sediment, rock, microbes and carbon reservoirs within…

Potentially bioavailable iron produced through benthic cycling in glaciated Arctic fjords of Svalbard Open

Katja Laufer, Alexander B. Michaud, Markus Maisch, James M. Byrne, Andreas Kappler , et al. · 2021

The Arctic has the highest warming rates on Earth. Glaciated fjord ecosystems, which are hotspots of carbon cycling and burial, are extremely sensitive to this warming. Glaciers are important for the transport of iron from land to sea and …

A ferrous wheel beneath the Antarctic Ice Sheet Open

Jon Hawkings, Mark Skidmore, John C. Priscu, Elizabeth Shoenfelt Troein, Christina Davis , et al. · 2021

Bioavailable iron produced through benthic cycling in glaciated Arctic fjords (Svalbard) Open

Katja Laufer, Alexander B. Michaud, Markus Maisch, J. R. Byrne, Andreas Kappler , et al. · 2020

The Arctic has the highest warming rates world-wide. Glaciated fjord ecosystems, which are known hotspots of carbon cycling and burial, are predicted to be extremely sensitive to this warming. Glaciers are important sources of iron, an ess…

Environmentally clean access to Antarctic subglacial aquatic environments Open

Alexander B. Michaud, Trista J. Vick‐Majors, Amanda M. Achberger, Mark Skidmore, Brent C. Christner , et al. · 2020

Subglacial Antarctic aquatic environments are important targets for scientific exploration due to the unique ecosystems they support and their sediments containing palaeoenvironmental records. Directly accessing these environments while pr…

Benthic Fe-cycling in fjord sediments enhances the reactivity of glacially derived Fe in Arctic fjords of Svalbard Open

Katja Laufer, Alexander B. Michaud, Hans Røy, Bo Barker Jørgensen · 2020

<p>Glacial runoff is a significant source of Fe to high-latitude marine environments. The amount and characteristics of glacially derived Fe depends on bedrock lithology, glacial comminution as well as glacier type. Because much of t…

Biogeochemical Connectivity Between Freshwater Ecosystems beneath the West Antarctic Ice Sheet and the Sub‐Ice Marine Environment Open

Trista J. Vick‐Majors, Alexander B. Michaud, Mark Skidmore, Clara Turetta, Carlo Barbante , et al. · 2020

Although subglacial aquatic environments are widespread beneath the Antarctic ice sheet, subglacial biogeochemistry is not well understood, and the contribution of subglacial water to coastal ocean carbon and nutrient cycling remains poorl…

GBASE_Exitation_Emission_Matrix Open

Alexander B. Michaud, John C. Priscu · 2020

This dataset contains the Exitation Emission Matrix data associated with GBASE: Geomicrobiology of Antarctic Subglacial Environments - Subglacial Lake Whillans.\n\nFor the dataset metadata, please see: https://ipt.biodiversity.aq/resource?…

GBASE_Exitation_Emission_Matrix Open

Alexander B. Michaud, John C. Priscu · 2020

This dataset contains the Exitation Emission Matrix data associated with GBASE: Geomicrobiology of Antarctic Subglacial Environments - Subglacial Lake Whillans. For the dataset metadata, please see: https://ipt.biodiversity.aq/resource?r=g…

Glacial influence on the iron and sulfur cycles in Arctic fjord sediments (Svalbard) Open

Alexander B. Michaud, Katja Laufer, Alyssa Findlay, André Pellerin, Gilad Antler , et al. · 2020

X-Ray Vision in the Arctic Tundra: Exploring How Redox Biogeochemistry Influences Ecosystem Processes Open

Elizabeth Herndon, Lauren Kinsman‐Costello, Alexander B. Michaud, David Emerson, William B. Bowden · 2020

Glacial controls on redox-sensitive trace element cycling in Arctic fjord sediments (Spitsbergen, Svalbard) Open

Lisa C. Herbert, Natascha Riedinger, Alexander B. Michaud, Katja Laufer, Hans Røy , et al. · 2019

Reactivity of Iron Minerals in the Seabed Toward Microbial Reduction – A Comparison of Different Extraction Techniques Open

Katja Laufer, Alexander B. Michaud, Hans Røy, Bo Barker Jørgensen · 2019

Dissimilatory iron reduction and sulfate reduction are the most important processes for anaerobic mineralization of organic carbon in marine sediments. The thermodynamics and kinetics of microbial Fe(III) reduction depend on the characteri…

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