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Maria Prokopenko

Visiting Assistant Professor of Geology
With Pomona Since: 2014
  • Expertise

    Expertise

    My research is driven by questions of how the processes occurring in the ocean are shaped by interactions between the three major components of the Earth system: the bio-, hydro- and geo-spheres. I look to identify and characterize the links between biologically driven fluxes and physical processes in the oceans on a variety of spatial and temporal scales. I study the distribution of various biogeochemical tracers, such as nutrient concentrations and stoichiometries, dissolved gases (N2, O2 and Ar), as well as nitrogen (δ15N) and oxygen (δ18O and δ17O) isotope ratios. I apply this information to quantify the rates of the biogeochemical N, O and C cycling constructing simple geochemical models. The magnitude, as well as spatial and temporal dynamics of the biogeochemical fluxes is comparable to a chemical heartbeat of Earth’s ecosystems, and can be used to diagnose the influence of various environmental factors. Such information is crucial for our ability, as a society, to predict potential consequences of the ongoing rapid environmental change on marine ecosystems.

    Research Interests

    • Application of stable isotope methods in studies of marine biogeochemical cycles
    • Nitrogen cycling in the modern and ancient oceans
    • Biological productivity and marine oxygen cycle
  • Work

    Work

    Papers (within last 6 years):

    * denotes student author

    Wang X.T.*, Sigman D.M., Prokopenko M.G., Adkins J.F., Robinson L.F., Hines* S.K., Chai J. Studer A.S., Martinez-Garcia A., Chen T. , Haug G.H. (2017) “Deep-sea coral evidence for lower Southern Ocean surface nitrate concentrations during the last ice age”

    William Z. Haskell II*, Maria G. Prokopenko, Douglas E. Hammond, Rachel H. R. Stanley, Zoe O. Sandwith (2017) “Annual cyclicity in export efficiency in the inner Southern California Bight” DOI: 10.1002/2016GB005561

    Haskell, W.Z.*, Prokopenko, M.G., Hammond, D.E., Stanley, R.H.R., Berelson, W.M., Baronas, J.J.*, Fleming, J.C. and Aluwihare, L.  (2016) “An organic carbon budget for coastal Southern California determined by estimates of vertical nutrient flux, net community production and export,” Deep Sea Research Part I: Oceanographic Research Papers, 116: 49-76.

    Haskell, W.Z., Prokopenko, M.G., Stanley, R.H.R. and Knapp, A.N. (2016) “Estimates of vertical turbulent mixing used to determine a vertical gradient in net and gross oxygen production in the oligotrophic South Pacific Gyre,” Geophysical Research Letters, 43(14): 7590-7599

    Angela N. Knapp, Karen L. Casciotti, William M. Berelson, Maria G. Prokopenko, and Douglas G. Capone (2016) “Low rates of nitrogen fixation in eastern tropical South Pacific surface waters,” Proceedings of the National Academy of Sciences, vol.113, n. 16, 4398-4404

    Haskell, William, Z.*, Hammond, Douglas E., Prokopenko, Maria G. (2015) “A dual-tracer approach to estimate upwelling velocity in coastal Southern California,” Earth and Planetary Science Letters, 422, 138-149

    Yeung, Laurence Y.; Berelson, William M.; Hammond, Douglas E.; Prokopenko, Maria G.; Wolfe, Christa*; Rollins, Nick (2015) “Upper-ocean gas dynamics for biogeochemical applications using radon profiles in the Eastern Tropical South Pacific,” Deep Sea Research Part I, vol. 99, pp. 35-45

    Tems, Caitlin E.*, Berelson, William M., Prokopenko, Maria G. (2015) “δ15N in laminated marine sediments provide a proxy for mixing between the California Undercurrent and the California Current: A proof of concept,” Geophysical Research Letters, DOI: 10.1002/2014GL061993

    Berelson, WM; Haskell II, WZ*; Prokopenko, M; Knapp, AN; Hammond, DE; Rollins, N; Capone, DG, (2015) “Biogenic particle flux and benthic remineralization in the Eastern Tropical South Pacific,” Deep Sea Research Part I: Oceanographic Research Papers, DOI:10.1016/j.dsr.2014.12.006

    Haskell, William Z.II*, Kadko, David, Hammond, Douglas E., Knapp, Angela N., Prokopenko, Maria G., Berelson, William M., Capone, Douglas G. (2015) “Upwelling velocity and eddy diffusivity from 7Be measurements used to compare vertical nutrient flux to export POC flux in the Eastern Tropical South Pacific,” 2015, Marine Chemistry, 168, pp. 140-150

    Townsend-Small, A., Prokopenko, M.G., Berelson W.M.  (2014), “Nitrous oxide cycling in the water column and sediments of the oxygen minimum zone, eastern subtropical North Pacific, Southern California, and Northern Mexico (23° N–34° N),” Journal of Geophysical Research: Oceans, 119 (5), pp.3158-3170

    Morales, L.V.*; Granger, J.; Chang, B. X.; Prokopenko, M. G. ; Plessen, B.; Gradinger, R.; Sigman, D.M. (2014), “Elevated 15N/14N in particulate organic matter, zooplankton, and diatom frustule-bound nitrogen in the ice-covered water column of the Bering sea eastern shelf,” Deep Sea Research Part II: Topical Studies in Oceanography       

    Wang, X. T.*; Prokopenko, M. G.; Sigman, D. M.; Adkins, J. F.; Robinson, L.F.; Ren, H.; Oleynik, S.; Williams, B.; Haug, G. H. (2014), “Isotopic composition of carbonate-bound organic nitrogen in deep-sea scleractinian corals: A new window into past biogeochemical change,” Earth and Planetary Science Letters, 400, 243-250

    Prokopenko, M.G., M.B. Hirst*, L. De Brabandere, W.M. Berelson, D.J. Lawrence*, J. Granger, B. X. Chang, S. Dawson., E.J. Crane, L. Chong*, B. Thamdrup , A. Townsend-Small, D.M. Sigman (2013) “Syntrophy between anammox bacteria and Thioploca drives nitrogen losses in anoxic marine sediments,” Nature, v. 500, pp. 194-198, doi:10.1038/nature12365

    Granger, J., Prokopenko, M.G., Mordy, C.W. and Sigman, D.M. (2013) “The proportion of remineralized nitrate on the ice-covered eastern Bering Sea shelf evidenced from the oxygen isotope ratio of nitrate,” Global Biogeochemical Cycles, 27(3), pp. 962-971.

    *Chong, L., Prokopenko, M.G., Berelson, W.M., Townsend-Small, A., McManus, J. (2012) “Nitrogen cycling within suboxic and anoxic marine sediments from the continental margin of Western North America,” Marine Chemistry, v. 128, pp. 13-25, doi:10.1016/j.marchem.2011.10.007

    Yeung, L.Y., W. M. Berelson, E. D. Young, M.G. Prokopenko,  N. Rollins, V.J. Coles, J. P. Montoya,  E. J. Carpenter, and P. L. Yager (2012) “Impact of diatom-diazotroph associations on carbon export in the Amazon River plume,” Geophysical Research Letters, 39, 6, doi: L18609 10.1029/2012gl053356

    Sañudo-Wilhelmy S.A., L. Cutter, R. Durazo, E. Smail*, L. Gomez-Consarnau, E. A. Webb, M. Prokopenko, D.M. Karl and W. M. Berelson (2012) “Multiple B-vitamin deficiency in large areas of the coastal ocean,”,PNAS, doi:10.1073/pnas.1208755109

    Ren, H., Sigman, D.M., Thunnel, R.C., Prokopenko, M.G., “Nitrogen isotopic composition of planktonic foraminifera from the modern and recent sediments,” (2012) Limnology and Oceanography, 57(4), 1011-1024, doi: 10.4319/lo.2012.57.4.1011

    Silver, Bianca J.*, Raymond, R., Sigman, D.,  Prokopenko, M.,  Sherwood Lollar, B.,  Lacrampe-Couloume, G.,  Fogel, M., Pratt, L., Lefticariu, L., Onstott, T. (2012)The origin of NO3- and N2 in deep subsurface fracture water of South Africa,” Chemical Geology, v. 294-295, pp. 51-62, doi:10.1016/j.chemgeo.2011.11.01

    Prokopenko, M.G., Sigman, D.M., Berelson, W.M., Hammond, D.E., Barnett, B., Chong, L*, Townsend-Small, A. (2011) “Denitrification in anoxic sediments supported by biological nitrate transport,” Geochimica et Cosmochimica Acta, doi:10.1016/j.gca.2011.09.023

    Prokopenko, M.G., Pauluis, O. M., Granger, J., Yeung, L. Y. (2011) “Exact evaluation of gross photosynthetic production from the oxygen triple-isotope composition of O2: Implications for the net-to-gross primary production ratios,” Geophys. Res. Letters, 38, doi:10.1029/2011GL047652

    Granger, J., Prokopenko, M.G., Sigman, D. , Mordy C., Morse, Z., Morales, L*., Sambrotto, R., Plessen B. (2011) “Nitrification-coupled denitrification in sediment of the eastern Bering Sea shelf leads to 15N-enrichment of fixed N in shelf waters,”  Journal of Geophysical Research –Oceans, doi:10.1029/2010JC006751

  • Education

    Education

    B.S., Moscow State University, Geology

    B.A., Moscow Institute of Foreign Languages, English

    M.S., University of Cincinnati, Geology

    Ph.D., University of Southern California (USC), Los Angeles, Earth Sciences

    Postdoc, Princeton University, Stable Isotope Geochemistry

    Postdoc, University of Southern California, Geochemistry/Oceanography

    Recent Courses Taught

    • Global Biogeochemical Cycles: Past and Present
    • Introduction to Geochemistry
    • Intro to Geology: Oceanography