MARINE & SUBSURFACE GEOCHEMISTRY
McDermott Lab
The McDermott Lab investigates the aqueous, volatile, and biogeochemical processes that govern energy flow and elemental cycling in reducing environments of the deep ocean and the subsurface. We focus on hydrothermal vents, warm springs, seafloor seeps, and ancient fracture waters accessed through deep mines, settings where water–mineral reactions, redox gradients, and thermodynamics shape the chemical foundations of life. These systems link fundamental geological and biological processes that sustain the deep subsurface biosphere and serve as modern analogues for the early Earth, when abiotic and biotic chemistry first converged.
Our work is inherently interdisciplinary, bridging geochemistry, geology, biology, and engineering to understand how chemical energy and fluid–rock interactions fuel ecosystems in extreme environments. We integrate field observations, isotopic and thermodynamic analyses, and modeling to trace the origins and transformation of carbon-, sulfur-, and metal-bearing compounds in hydrothermal and subsurface fluids.
A central goal is to couple geochemical measurements with emerging technologies for in situ sampling and analysis. In collaboration with engineers and molecular biologists, we deploy pressure-retaining samplers, sensors, and environmental ‘omics tools to capture transient events, preserve redox-sensitive chemical species, and quantify energy transfer from abiotic compounds to ecosystems. Together, these efforts expand our ability to observe, understand, and predict biogeochemical processes in the deep ocean.
Current Members
Jill McDermott
Center Director
Principal Investigator
F. Hook Associate Professor
Jill is a Chemical Oceanographer trained at the Massachusetts Institute of Technology, the Woods Hole Oceanographic Institution and the University of New Hampshire.
Jessica Rodgers
Graduate Researcher
Jess is interested in hydrothermal vents, marine biogeochemistry, inorganic and organic geochemistry, the origin of life, and life in extreme environments. Before joining the lab, Jess was a Research Assistant at the Woods Hole Oceanographic Institution.
Jada Siverand
NSF Graduate Research Fellow
Jada investigates subseafloor fluid circulation patterns, hydrothermal metals export, and viable conditions for venting off-axis of MOR spreading centers.
Esmira Bibaj
Graduate Researcher
Esmira is interested in examining the biogeochemistry of hydrothermal vent systems.
Amanda Pearson
Undergraduate Researcher
Amanda is pursuing a B.S. in Chemistry and a minor in Earth and Environmental Sciences.
Former Members
William Dowd
Graduate Researcher
William graduated with a Ph.D. from Lehigh University and went to work as an Environmental Chemist at Gradient in Boston, Massachusetts.
Connor Downing
Graduate Researcher
Connor graduated with a Masters from Lehigh University and went to work at Cooper Environmental.
Susan Ambrose
Graduate Researcher
Susan graduated with a Masters from Lehigh University and went to work as an Environmental Chemist at M.J. Reider Associates
Tiffany Baumann
Undergraduate Researcher
Tiffany went on to pursue a Masters in Earth and Environmental Science at Lehigh University
Talia Rodkey
Undergraduate Researcher
Talia went to work as an Applications and Support Engineer at Bruker Alicona
Grant Loescher
Undergraduate Researcher
Grant went on to pursue a Masters in Geological Science at the Arizona State University
Kelden Pehr
Postdoctoral Research Fellow
Kelden went to work as a tenure-track Assistant Professor at the University of North Dakota
Henry Price
Undergraduate Researcher
After obtaining a NSF GRFP, Henry went to pursue a Ph.D. in Material Science and Engineering at MIT
Fieldwork
From the deep ocean, to deep within the Earth's crust.
Oceanographic Research Expeditions
2025 R/V Atlantis, HOV Alvin, expedition (AT50-42) to the Juan De Fuca Ridge, Canada.
2025 R/V Atlantis/HOV Alvin and AUV Sentry expedition (AT50-33) to 9°50’N East Pacific Rise.
2024 R/V Atlantis/HOV Alvin and AUV Sentry expedition (AT50-21) to 9°50’N East Pacific Rise.
2023 R/V Falkor (too)/ROV Subastian expedition (FKt230812) to the Eastern Galapagos Spreading Center.
2023 R/V Atlantis/HOV Alvin and AUV Sentry expedition (AT50-07) to 9°50’N East Pacific Rise.
2021 R/V Roger Revelle/ROV Jason and AUV Sentry expedition (RR2102) to 9°50’N East Pacific Rise.
2019 R/V Manta/AUV Mesobot to the Gulf of Mexico.
2019 R/V Pelican/ROV Global Explorer to the Gulf of Mexico
2018 R/V JOIDES Resolution (Expedition #376) to Brothers Arc Volcano
2017 E/V Nautilus/ROV Hercules to Pescadero Basin
2016 R/V Polarstern/HROV Nereid Under Ice to Gakkel Ridge
2013 R/V Falkor/HROV Nereus expedition (FK008) to Mid-Cayman Rise
2012 R/V Atlantis/ROV Jason II expedition (AT18-16) to Mid-Cayman Rise
2011 R/V Okeanos Explorer/ROV Little Hercules expedition to Mid-Cayman Rise (link; via tele-presence)
2009 R/V Cape Hatteras/HROV Nereus expedition to Mid-Cayman Rise
2007 R/V Atlantis/DSV Alvin expedition (AT15-27) to 9°50’N East Pacific Rise (starboard observer on Alvin dive #4380)
2006 R/V Atlantis/DSV Alvin expedition (AT15-13) to 9°50’N East Pacific Rise (starboard observer on Alvin dive #4279)
2006 R/V Atlantis/DSV Alvin expedition (AT15-06) to 9°50’N East Pacific Rise
Land Research Expeditions
2022 Fluid and gas sampling at Soudan Mine Underground State Park, MN, USA
2019 Fluid and gas sampling at Soudan Mine Underground State Park, MN, USA
2016 Rock and gas sampling expedition at gold mine in Preissac, QC, Canada
2016 Rock and fluid sampling expedition at base metal mine in Sudbury, ON, Canada
2015 Rock, fluid and gas sampling expedition at base metal mine in Timmins, ON, Canada
2015 Rock core and fluid sampling campaign at Grimsel Test Site, Switzerland
2014 Borehole fluid and gas sampling expedition at base metal mine in Sudbury, ON, Canada
Publications
Wu J.-N., Parnell-Turner R., Fornari D.J., Barreyre T., McDermott J.M. (2025). Quantifying widespread hydrothermal chimneys on the East Pacific Rise flanks between 9°43′–57′N. Science Advances, 11(45), eadv0788. https://doi.org/10.1126/sciadv.adv0788
McCartin L., Govindarajan A., McDermott J.M., Herrera S. (2025). Limited dispersal of benthic environmental DNA from a subtropical mesophotic shelf-edge bank. Environmental DNA, 7, e70204. https://doi.org/10.1101/2023.10.26.564240
Barreyre T., Olive J.-A., Fornari D.J., McDermott J.M., Parnell-Turner R., Moutard K., Wu J.-N., Marjanović M. (2025). Hydrothermal vent temperatures track magmatic inflation and forecast eruptions at the East Pacific Rise. Proceedings of the National Academy of Sciences, 122(42), e2510245122. https://doi.org/10.1073/pnas.2510245122
Commentary: Chadwick W.W. (2025). Warming waters herald a submarine eruption. Proceedings of the National Academy of Sciences, 122(46), e2526455122. https://doi.org/10.1073/pnas.2526455122
Albers E., Diehl A., Fitzsimmons J.N., Jensen L.T., Klein F., McDermott J.M., Purser A., Seewald J.S., Walter M., Wegener G., Bach W., Boetius A., German C.R. (2025). Ultramafic-influenced submarine venting on basaltic seafloor at the Polaris site, 87°N, Gakkel Ridge. Earth & Planetary Science Letters, 651, 119166. https://doi.org/10.1016/j.epsl.2024.119166
Schuler C.J., Patsis A., Alexander S.C., Hsu D., Dowd W.S., Lee W., Matzen S.L., Marcus M.A., Sheik C.S., McDermott J.M., Kang P.K., Santelli C.M., Toner B.M. (2024). Densely populated biofilms and linked iron and sulfur cycles in the fractured-rock continental subsurface. Geochimica et Cosmochimica Acta, 375, 229–246. https://doi.org/10.1016/j.gca.2024.04.019
Berrios-Rivera N., Gee J.S., Parnell-Turner R., Maher S., Wu J.-N., Fornari D.J., Tivey M., Marjanović M., Barreyre T., McDermott J.M. (2023). Significance of short-wavelength magnetic anomaly low along the East Pacific Rise axis, 9°50′N. Geochemistry, Geophysics, Geosystems, 24(5), e2023GC010875. https://doi.org/10.1029/2023GC010875
Wu J.-N., Parnell-Turner R., Fornari D.J., Berrios-Rivera N., Barreyre T., McDermott J.M. (2023). The role of on- and off-axis faults and fissures during eruption cycles and crustal accretion at 9°50′N, East Pacific Rise. Geochemistry, Geophysics, Geosystems, 24(4), e2022GC010794. https://doi.org/10.1029/2022GC010794
Govindarajan A.F., McCartin L., Adams A., Allan E., Belani A., Francolini R., Fujii J., Gomez-Ibanez D., Kukulya A., Marin F., Tradd K., Yoerger D.R., McDermott J.M., Herrera S. (2022). Improved biodiversity detection using a large-volume environmental DNA sampler with in situ filtration and implications for marine eDNA sampling strategies. Deep-Sea Research Part I: Oceanographic Research Papers, 103871. https://doi.org/10.1016/j.dsr.2022.103871
Dowd W.S., Schuler C.J., Santelli C.M., Toner B.M., Sheik C.S., Pehr K., McDermott J.M. (2022). Potential energy sources for the deep continental biosphere in isolated anoxic brines. Earth & Planetary Science Letters, 595, 117720. https://doi.org/10.1016/j.epsl.2022.117720
McDermott J.M., Parnell-Turner R., Barreyre T., Herrera S., Downing C.C., Pittoors N., Pehr K., Vohsen S.A., Dowd W.S., Wu J.-N., Marjanović M., Fornari D.J. (2022). Discovery of active off-axis hydrothermal vents at 9°54′N, East Pacific Rise. Proceedings of the National Academy of Sciences, 119(30), e2205602119. https://doi.org/10.1073/pnas.2205602119
Commentary: Seyfried W.E., & Karson J.A. (2022). Surprising discovery of off-axis hydrothermal venting on the East Pacific Rise. Proceedings of the National Academy of Sciences, 119(31), e2210175119. https://doi.org/10.1073/pnas.2210175119
McCartin L.J., Vohsen S.A., Ambrose S.W., Layden M., McFadden C.S., Cordes E.E., McDermott J.M., Herrera S. (2022). Temperature controls eDNA persistence across physicochemical conditions in seawater. Environmental Science & Technology. 56, 8629−8639.
https://doi.org/10.1021/acs.est.2c01672
Pereira S.I., Diehl A., McDermott J.M., Pape T., Klose L., Strauss H., Bohrmann G., Bach W. (2022). Geochemistry of hydrothermal fluids from the E2-segment of the East Scotia Ridge: Magmatic input, reaction zone processes, fluid mixing regimes and bioenergetic landscapes. Frontiers in Marine Science, 9, 765648. https://doi.org/10.3389/fmars.2022.765648
Wu J.-N., Parnell-Turner R., Fornari D.J., Kurras G., Berrios-Rivera N., Barreyre T., McDermott J.M. (2022). Extent and volume of lava flows erupted at 9°50′N, East Pacific Rise in 2005–2006 from autonomous underwater vehicle surveys. Geochemistry, Geophysics, Geosystems, 23, e2021GC010213. https://doi.org/10.1029/2021GC010213
Sherwood Lollar B., Heuer V.B., McDermott J.M., Tille S., Warr O., Moran J.J., Telling J., Hinrichs K.-U. (2021). A window into the abiotic carbon cycle—Acetate and formate in fracture waters in 2.7 billion-year-old host rocks of the Canadian Shield. Geochimica et Cosmochimica Acta, 294, 295–314. https://doi.org/10.1016/j.gca.2020.11.026
McDermott J.M., Sylva S.P., Ono S., German C.R., Seewald J.S. (2020). Abiotic redox reactions in hydrothermal mixing zones: Decreased energy availability for the subsurface biosphere. Proceedings of the National Academy of Sciences, 117(34), 20453–20461. https://doi.org/10.1073/pnas.2003108117
Wygel C., Peters S., McDermott J.M., Sahagian D. (2019). Bubbles and dust: Experimental results of dissolution rates of metal salts and glasses from volcanic ash deposits in terms of surface area and human health impacts. GeoHealth, 3, 338-355.
https://doi.org/10.1029/2018GH000181
de Ronde C.E.J., Humphris S.E., Höfig T.W., Reyes A.G., and the IODP Expedition 376 Scientists (including Brandl P.A., Cai L., Cai Y., Caratori Tontini F., Deans J.R., Farough A., Jamieson J.W., Kolandaivelu K.P., Kutovaya A., Labonté J., Martin A.J., Massiot C., McDermott J.M., McIntosh I.M., Nozaki T., Pellizari V.H., Roberts S., Rouxel O., Schlicht L.E.M., Seo J.H., Straub S.M., Strehlow K., Takai K., Tanner D., Tepley III F.J., Zhang C.) (2019). Critical role of caldera collapse in the formation of seafloor mineralization: The case of Brothers volcano. Geology, 47(8), 762–766. https://doi.org/10.1130/G46047.1
McDermott J.M., Sylva S.P., Ono S., German C.R., Seewald J.S. (2018). Geochemistry of fluids from Earth’s deepest ridge-crest hot springs: Piccard hydrothermal field, Mid-Cayman Rise. Geochimica et Cosmochimica Acta, 228, 95–118. https://doi.org/10.1016/j.gca.2018.01.021
Wang D.T., Reeves E.P., McDermott J.M., Seewald J.S., Ono S. (2018). Clumped isotopologue constraints on the origin of methane at seafloor hot springs. Geochimica et Cosmochimica Acta, 223, 141–158. https://doi.org/10.1016/j.gca.2017.11.030
Warr O., Sherwood Lollar B., Fellowes J., Sutcliffe C.N., McDermott J.M., Holland G., Mabry J.C., Ballentine C.J. (2018). Tracing ancient hydrogeological fracture network age and compartmentalization using noble gases. Geochimica et Cosmochimica Acta, 222, 340–362. https://doi.org/10.1016/j.gca.2017.10.022
Anderson R.E., Reveillaud J.C., Reddington E., Delmont T.O., Eren A.M., McDermott J.M., Seewald J.S., Huber J.A. (2017). Genomic variation in natural microbial populations inhabiting the marine seafloor. Nature Communications, 8, 1114. https://doi.org/10.1038/s41467-017-01228-6
Michel A.P.M., Wankel S.D., Beaulieu S., Soule S.A., Mullineaux L., Coleman D., Escobar-Briones E., Gaytan-Caballero A., McDermott J.M., Mills S., Speth D., Zierenberg R. (2017) Biogeochemical exploration of the Pescadero Basin vents. Oceanography, Suppl. 31(1), 42–43. https://escholarship.org/uc/item/0hx54268
Li L., Wing B.A., Bui T.H., McDermott J.M., Slater G.F., Wei S., Lacrampe-Couloume G., Sherwood Lollar B. (2016). Sulfur mass-independent fractionation in subsurface fracture waters indicates a long-standing sulfur cycle in Precambrian rocks. Nature Communications, 7, 13252. https://doi.org/10.1038/ncomms13252
Reveillaud J.C., Reddington E., McDermott J.M., Algar C., Meyer J.L., Sylva S.P., Seewald J.S., German C.R., Huber J.A. (2016). Subseafloor microbial populations in hydrogen-rich vent fluids from the Mid-Cayman Rise. Environmental Microbiology, 18(6). https://doi.org/10.1111/1462-2920.13173
McDermott J.M., Seewald J.S., German C.R., Sylva S.P. (2015). Pathways for abiotic organic synthesis at submarine hydrothermal fields. Proceedings of the National Academy of Sciences, 112(25), 7668–7672. https://doi.org/10.1073/pnas.1506295112
McDermott J.M., Ono S., Tivey M.K., Seewald J.S., Shanks III W.C., Solow A.R. (2015). Identification of sulfur sources and isotopic equilibria in submarine hot springs using multiple sulfur isotopes. Geochimica et Cosmochimica Acta, 160, 169–187. https://doi.org/10.1016/j.gca.2015.02.016
Reeves E.P., McDermott J.M., Seewald J.S. (2014). The origin of methanethiol in midocean ridge hydrothermal fluids. Proceedings of the National Academy of Sciences, 111(15), 5474–5479. https://doi.org/10.1073/pnas.1400643111
Bennett S.A., Statham P.J., Green D.R.H., Le Bris N., McDermott J.M., Prado F., Rouxel O.J., Von Damm K.L., German C.R. (2011). Dissolved and particulate organic carbon in hydrothermal plumes from the East Pacific Rise, 9°50′N. Deep-Sea Research Part I: Oceanographic Research Papers, 58(9), 922–931. https://doi.org/10.1016/j.dsr.2011.06.010
German C.R., Bowen A., Coleman M.L., Honig D.L., Huber J.A., Jakuba M.V., Kinsey J.C., Kurz M.D., Leroy S., McDermott J.M., Mercier de Lépinay B., Nakamura K., Seewald J.S., Smith J., Sylva S.P., Van Dover C.L., Whitcomb L.L., Yoerger D.R. (2010). Diverse styles of submarine venting on the ultra-slow spreading Mid-Cayman Rise. Proceedings of the National Academy of Sciences, 107(32), 14020–14025. https://doi.org/10.1073/pnas.1009205107
