Research Themes

Some of the driving motivations to my research involve the curiosity towards questions like

(i) What is the role of methane cycling in aquatic and sedimentary carbon cycling? How has it changed over the geological past? And how will it change in the future?

(ii) How do carbon and associated elements cycle through different geosystems, especially the aquatic and shallow sedimentary regimes? How do these processes link together in our climate system over short and long (geological) time scales?

(iii) How can we use sediment/rock records to evaluate these biogeochemical processes in the geological past and further the possibility of such processes in other habitable planets/moons?

(iv) How can we channel our understanding of biogeochemical complexities in the Earth system towards sustainability goals under rapid global change?

A few recent research projects involve:

(i) Methane-carbon cycling in ocean margins and inland waters (especially stratified lakes).

(ii) Carbon and associated elemental budgets in lacustrine and marine settings

(iii) Biogeochemical impacts of offshore hydrocarbon and methane seep on the shallow marine sediments-seafloor-water column-atmosphere system.

(iv) Role of methane-derived authigenic carbonates (MDAC) on the marine carbon budget at present and over the geological history

(v) Bottom-up perspective of ocean acidification - the role of benthic carbon flux to the water column and how it affects the carbonate chemistry of the water (marine and inland waters).

(v) Geological signatures of microbial life and their implication to Astrobiology

“I have had my results for a long time, but I do not yet know how I am to arrive at them” - Carl Friedrich Gauss

Research Projects

Theme: Marine Methane Cycling and Authigenic Carbonates

This line of research aims to better understand the dynamics of deep-sea settings impacted my subsurface methane and hydrocarbon transport. My particular focus has been in developing carbon budgets at these sites, understand the authigenic carbonate precipitation pathways, and to decode the sedimentary imprints of these dynamic biogeochemical interactions.

Selected reading:

Outreach Articles:

Deep sea rocks as unique story tellers: https://shorturl.at/fsnFS

US Ocean Carbon Biogeochemistry outreach on methane-carbon cycling: https://www.us-ocb.org/a-methane-charged-carbon-pump-in-shallow-marine-sediments/

Manuscripts:

Akam, S.A., Swanner, E. D., Yao, H., Hong, W.-L., and Peckmann, J., 2023, Methane-derived authigenic carbonates – A case for a globally relevant marine carbonate factory. Earth-Science Reviews, p. 104487. https://doi.org/10.1016/j.earscirev.2023.104487 (pdf)

Akam, S.A., Lyons, T.W., Coffin, R.B., McGee, D., Naehr, T.H., Bates, S.M., Clarkson, C. and Reese, B.K., 2021. Carbon-sulfur signals of methane versus crude oil diagenetic decomposition and U-Th age relationships for authigenic carbonates from asphalt seeps, southern Gulf of Mexico. Chemical Geology, p.120395. https://doi.org/10.1016/j.chemgeo.2021.120395 (pdf)

Akam, S.A., Coffin, R.B., Abdulla, H.A.N., and T.W Lyons (2020). A Dissolved Inorganic Carbon Pump in Methane Charged Shallow Marine Sediment Systems: State of the Art and New Model Perspectives, Frontiers in Marine Science, 7:206, https://doi.org/10.3389/fmars.2020.00206 (pdf)

In progress:

I/Ca dynamics of Methane seep carbonates

Biomarker patterns on methane-impacted sediments

Theme: Earth's Early Biogeochemistry

This line of research aims to understand the biogeochemical interactions in early Earth, especially in Archaean earth (4 to 2.5 billion years ago), which were pivotal for Earth's habitability. I explore the plausible paleoenvironmental conditions and microbial processes that were occurring in Earth's earliest oceans to better inform us about the factors that lead to life's early evolution on our planet. I have been exploring the biogeochemical processes, especially the one's pertaining to carbon, methane, iron, and sulfur cycling, in certain lake systems which are established analog to address some of these research questions.

Selected Reading:

Outreach Articles:

A Minneapolis Lake Providing a Scientific Window to Study Earth’s Early History : https://shorturl.at/HS364

Akam, S. A., Chuang, P. C., Katsev, S., Wittkop, C., Chamberlain, M., Dale, A. W., ... & Swanner, E. D. (2024). Methane-carbon budget of a ferruginous meromictic lake and implications for marine methane dynamics on early Earth. Geology, 52(3), 187-192. https://doi.org/10.1130/G51713.1

Gilleaudeau, G.J., Chen, X., Romaniello, S.J., Akam, S.A., Wittkop, C., Katsev, S., Anbar, A.D. and Swanner, E.D., 2025. Uranium isotope systematics of a low-productivity ferruginous ocean analog: Implications for the uranium isotope record of early Earth. Geochimica et Cosmochimica Acta. https://doi.org/10.1016/j.gca.2025.01.011

Theme: Lake Biogeochemistry and Hydrology

This line of work explores general geology, geochemistry, and hydrology of lake systems.

Kniptash, R., Akam, S.A., Swanner, E.D., Meyer, J.R., Local-scale hydrogeologic controls on groundwater discharge areas to a ferruginous, meromictic kettle lake (accepted to Hydrogeology)

Smith, E.S., Harding, C., Akam, S.A, Lascu, I., Ledesma, G., Poudel, P., Sun, H., Duncanson, S., Bandy, K., Branham, A…and Bryant-Tapper, L., 2024. Thermal stratification and meromixis in four dilute temperate zone lakes, Biogeosciences; https://doi.org/10.5194/bg-21-1549-2024

Stay tuned for more!