A luxuriant field of tubeworms (left) was obliterated by lava (right) during a seafloor eruption.
Research by Sasha Wagner and colleagues is featured in an article by Paul Voosen in Science News describing their once-in-a-lifetime encounter with mid-ocean ridge volcanism and its unexpected effects on the deep ocean.
The erosion of petrogenic (fossil) organic carbon from exposed rocks links lithology, climate, and the evolution of atmospheric CO2 over geologic timescales. When liberated, some fractions of petrogenic organic carbon are rapidly oxidized to CO2 and others are passively translocated from land to sea via rivers. Black carbon is one of these passive fractions of organic carbon and comes in a variety of forms like charcoal, soot, petroleum, and graphite-like materials that are relatively unreactive, stable on short and long timescales, and is environmentally long-lived.
Shale outcrop near the confluence of the upper Hudson and Mohawk Rivers at Peebles Island.
For the first time, we show particulate black carbon to be derived from the weathering and erosion of shales within the Hudson River basin. The amount and proportion of black carbon from shales increases with river flow. During peak flows, the composition of particulate black carbon is similar to that of shale rocks collected from within the upper Hudson and Mohawk subcatchments.
Crumbling shale at an outcrop near Amsterdam, NY.
This study was led by Alex Collins and was a collaborative effort of an all-RPI team of researchers! Together, our data show that underlying lithology has a first order control on particulate black carbon in river systems, and may be more important than historic wildfire activity in catchments underlain by organic-rich shales. We also suggest that particulate black carbon as a conservative tracer for petrogenic organic carbon, which is preferentially mobilized under moderate-to-high flow conditions, solidifying a link between short- and long-term carbon cycles.
This work is entitled “Substantial export of shale-derived particulate black carbon in the Hudson River indicated by compound-specific stable carbon isotopes (New York, United States)“ and was published in the journal Earth Surface Processes and Landforms.
Congratulations to Julia Hubbard who was awarded a $500 travel grant to attend the Deep Submergence Science Committee (DeSSC) New User Program in New Orleans, Louisiana ahead of the AGU Annual Meeting. At the conference, Julia will present her work on hydrothermal graphite and links between vent chimney mineralogy and dissolved black carbon in the deep ocean.
The DeSSC is a University-National Oceanographic Laboratory System (UNOLS) committee providing advisory responsibilities for the National Deep Submergence Facility.
Congratulations to Maddy Miller who was awarded a $1000 AGU Student Travel Grant! Funds will be used to support her travel to AGU Annual Meeting, where she will present her work on the influence of hydrology and recent wildfires on dissolved black carbon export behavior in the Yukon River, Alaska.
The AGU Student Travel Grants provide funds to assist students with a combination of costs associated with attending the AGU Annual Meeting.
Earlier this year, the Wagner lab had two students successfully defend their research – Congratulations to Dr. Riley Barton and Dr. Alex Collins!
Riley graduated this past spring and the title of her dissertation is “Hydrologic and spatiotemporal controls on pyrogenic carbon export from fire-affected, coastal California streams”. Riley’s work has tested long-standing hypotheses that challenge and expand our understanding of the effects of wildfire on carbon cycling in local waterways, with Earth system scale implications. Riley is now a postdoc with Kevin Bladon at Oregon State University.
Riley and Sasha at a site burned during the 2020 CZU Lightning Complex Fire.
Riley and collaborator, Lauren Giggy (UC Santa Cruz), at a stream sampling site at the Blue Oak Ranch Reserve.
Alex graduated this past summer and the title of his dissertation is “Investigating the dynamics of organic matter in the Hudson River catchment across spatial, temporal, and hydrologic regimes”. Alex’s work revealed the significant effect of damming and other impoundments on the composition and fate of organic matter in the Hudson River. His research on shale-derived inputs to the Hudson River have major implications for the source and age of black carbon observed in rivers globally. Alex is now a postdoc with Jake Hosen at Purdue University.
Alex collects shale from a roadcut within the Mohawk River catchment.
Alex teaches a class about carbon cycling in the greater Hudson River watershed.
In addition to their impactful research and academic successes, both Riley and Alex are exceptional mentors to other early career researchers and undergraduate students. This is the kind of stuff that is not reflected in resumes and CVs but makes a huge difference in collaborative success, impact on others, and the science itself. I am exceptionally lucky and thankful for the opportunity to work with both Riley and Alex. I have learned so much from them and wish them nothing but the best in their future endeavors.
There are approximately 126,000 petroleum-contaminated groundwater sites in the United States alone. Plumes of petroleum-contaminated groundwater carry a mixture of native (background) dissolved organic matter, petroleum hydrocarbons, and their degradation products. The environmental persistence of oil spills is of emerging concern because many of the petroleum degradation byproducts are not regulated, even though there is a large body of evidence to indicate they are harmful to mammals, aquatic invertebrates, amphibians, fish, and aquatic plants.
The molecular complexity of crude oils and their differing reactivity and environmental accumulation makes their behavior difficult to predict. Sasha Wagner has teamed up with David Podgorski at the University of New Orleans to investigate links between oil degradation products at contaminated groundwater sites to their petroleum source. They will also assess intrinsic and extrinsic controls on the environmental persistence of oil degradation byproducts. The analytically unresolved complex mixture is of particular interest, which defies characterization and quantification by traditional gas chromatography-based methods.
Alicia DiNovo collects groundwater samples.
Sampling of oil-contaminated soils.
This past summer, students from UNO and RPI traveled to Bemidji, Minnesota to sample petroleum-contaminated groundwater and soils at the site of a legacy oil spill that occurred in 1979. The remaining oil continues to be a source of contaminants to the aquifer and has been monitored as part of the USGS National Crude Oil Spill Fate and Natural Attenuation Research Site for the last 40 years. Our group has actively collected data from this site several times within the last decade, which will allow us to evaluate the mobility and persistence of crude oil fractions over time.
Processing groundwater samples - From left to right: Yahminiy Ganesh (UNO), Alicia DiNovo (RPI), Hunter Lee (UNO), and Savanna Grip (RPI).
Project funding information: National Science Foundation – Environmental Engineering (EnvE). Collaborative Research: Identification and Characterization of Petrogenic Compounds that Persist in Aquatic Environments. Award No. 2428602. D. Podgorski (PI), S. Wagner (PI).
During our expedition to the East Pacific Rise, our sampling site erupted! It is the first time humans have ever witnessed an active underwater eruption along a mid-ocean ridge, a string of volcanoes circling the globe like seams on a baseball. One day, we were exploring a living, vibrant community of fish, crabs, tubeworms, and mussels … the next day, the area was completely paved over by hardened black lava.
The exciting event was first covered by the New York Times and there was a press release from the Woods Hole Oceanographic Institution. Once we returned home, the RPI contingent shared their experience and perspective with the Times Union. The videos here show footage from the human-operated submarine, Alvin.
During oxidation of black carbon samples to produce benzenepolycarboxylic acids, pressure buildup within glass ampules can cause them to explode, resulting in sample loss, injury to ovens, or a "domino-effect" where breakage of one ampule shatters adjacent ones.
Here we provide schematics and detailed instructions for the manufacturing of The Aluminum Nitric-acid Keg, or TANK. This apparatus was designed to isolate individual samples during black carbon sample prep and to stop the domino-effect, decreasing sample loss and limiting the release of nitric acid fumes. Since it’s development, TANK also seems to reduce the occurrence of explosions overall, likely due to more consistent heating of samples in the aluminum block.
Riley and Maddy drill holes into TANK.
Early drawings of the apparatus.
TANK was designed and manufactured by students Maddy Miller, Riley Barton, and Alex Collins, with shop resources and guidance from Morgan Schaller. CAD files and blueprints are publicly available at protocols.io.
This spring, Sasha Wagner, Julia Hubbard, and Veronica Nowak sailed more than 1,000 miles west of Costa Rica to the East Pacific Rise in search of evidence that hydrothermal vents are a globally important source of long-lived organic carbon in the deep ocean. Some photos below of our 5-week voyage at sea! See more at our blog: Vent-uring into the Deep.
Departing Costa Rica - From left to right: Veronica Nowak, Julia Hubbard, and Sasha Wagner.
Science party gathering in the Main Lab on the R/V Atlantis.
The submersible, Alvin, emerges from it’s hangar.
Julia gets into Alvin for her second dive to the deep sea!
Amazing views of giant mussels, tubeworms, fish, and other macrofauna from inside Alvin.
Sasha in Alvin at the bottom of the ocean!
Hydrothermal vent chimney rock recovered from Tica.
Julia carefully recovers a chimney rock from the Alvin basket once back on deck.
Julia holds a chimney rock encrusted with tubeworm shells.
Our local Hudson River watershed includes a mix of forested and agricultural landscapes and flat and high relief areas. The frequency and intensity of storm events have been increasing in the northeastern United States, due to climate change. In some areas of the Hudson River catchment, water flow is restricted by dams and other impoundments. Together, these features also leave an imprint on the dissolved organic matter in the Hudson River.
Upper Hudson river in the evening.
This study was led by Alex Collins, who used optical measurements to evaluate the combined effects of these environmental features on dissolved organic matter dynamics in the Hudson River. He discovered that damming and hydrologic management, rather than land cover, had a greater effect on the type of dissolved organic matter in-stream. Furthermore, expected rainfall‐runoff impacts on dissolved organic matter were muted in areas where dams are prevalent. However, overall, storm events resulted in the export of more and browner dissolved organic matter to downstream areas.
Water is released over the Conklingville Dam - Times Union
This work is entitled “Hydrologic management convolutes expected spatiotemporal patterns of dissolved organic matter in the Hudson River” and was published in the Journal of Geophysical Research: Biogeosciences.
Dr. Sasha Wagner
Rensselaer Polytechnic Institute
Department of Earth and Environmental Sciences
110 8th Street, Troy, NY 12180
Contact: wagnes3@rpi.edu