Andrea M Erhardt

Short CV

Dr. Andrea Erhardt is an Associate Professor of Earth and Environmental Sciences at the University of Kentucky, USA.  She obtained her PhD in Geological Sciences from Stanford University, her Masters in Geology at the Colorado School of Mines, and her BSc in Environmental Engineering from Northwestern University. She did her postdoctoral research at the University of Cambridge, United Kingdom as a Canadian Institute for Advanced Research Postdoctoral Fellow. She is an isotope geochemist with a focus on using isotope chemistry tracers for environmental and climate change. As director of the Kentucky Stable Isotope Geochemistry Laboratory, she guides projects tracing climate-driven water cycle changes in precipitation and groundwater. Additionally, she uses isotope chemistry to reconstruct changing ocean chemistry over past climate events. She is active in advancing diversity, equity, and inclusivity initiatives, leading anti-racism initiatives, and supporting underrepresented students in the chemical and geosciences.

Selected Awards

• Using Deer Stable Isotope Data to Test A Niche Construction Hypothesis (2021)
• Outstanding Graduate Student Mentor Award, University of Kentucky (2020)
• IODP Expedition Support 378 (2020)                                                                
• Causes and extent of elevated groundwater methane concentrations in Eastern Kentucky Water Resources Research Institute (2018)
• Liquid Water Isotope Analyzer (Instrumentation Grant) (2018)
• Isotopic and geochemical analysis of fluid flow in a paleokarst system, San Andres Formation, West Texas (Pioneer Natural Resources) (2017-2020)
• Stable isotope analysis and paleooceanographic study of Wolfcamp Formation, West Texas (Pioneer Natural Resources) (2017-2019)

Research Interests

Isotopes as tracers of environmental change

Selected Publications

• *Avery, E., Samonina, O., Kryshtop, L., Vyshenska, I., Fryar, A.E., Erhardt, A.M., (2022). Precipitation patterns in Ukraine as derived for water isotope analysis. Isotopes in Environmental and Health Studies.
•  *Wilson, J.W., Erhardt, A.M. and Tobin, B.W., (2022). Using δ¹³C of dissolved inorganic carbon and dissolved organic carbon as tracers to characterize karst spring systems of the Shivwits Plateau at Grand Canyon National Park. Hydrogeology Journal,  https://doi.org/10.1007/s10040-022-02450-3
•  Erhardt, A.M., Douglas, G., Jacobson, A.D., Wimpenny, J., Yin, Q-Z., Paytan, A. (2021). Assessing sedimentary detrital Pb isotopes as a dust tracer in the Pacific Ocean. Paleoceanography and Paleoclimatology, 36 (4), e2020PA004144. DOI: 10.1029/2020PA004144
• Yao, W., Markovic, S., Paytan, A., Erhardt, A.M., Wortmann, U.G. (2021). Oxidation of sedimentary sulfides as a negative feedback to ice-sheet expansion. Earth and Planetary Science Letters, 568, 117015.  DOI: 10.1016/j.epsl.2021.117015
• de Wet, C.B., Erhardt, A.M., Sharp, W.D., Marks, N.E., Bradbury, H.J., Alexandra V. Turchyn, A.V., Xu, Y., Oster, J.L., (2021). Semi-quantitative estimates of rainfall variability during the 8.2kyr event in California using speleothem calcium isotope ratios. Geophysical Research Letters. e2020GL089154 DOI: 0.1029/2020GL089154
• Erhardt, A.M., Turchyn, A.V., Dickson, J.A.D., Sadekov, A.Y., Taylor, P.D., Wilson, M.A., Schrag, D.P. (2020). Carbonate hardgrounds suggest persistence of low Mg/Ca oceans over the Phanerozoic, Geochemistry, Geophysics, Geosystems, 21, e2019GC008448.
•  Erhardt, A.M, Turchyn, A.V., Bradbury, H.J., Dickson, J.A.D. (2020). The calcium isotopic composition of carbonate cements: A record of sedimentary carbonate precipitation and ocean chemistry? Chemical Geology, 540, 119490.  doi.org/10.1016/j.chemgeo.2020.119490
• *Reis, A., Erhardt, A.M., McGlue, M.M., Waite, L.  (2019). Evaluating the Effects of Post-Depositional Alteration of Carbonates on the Interpretation of δ¹³C_carb and δ¹⁸O_carb in a Mud-Rich Depositional Environment: A Case Study from the Midland Basin, USA. Chemical Geology, 524, 196-212. doi.org/10.1016/j.chemgeo.2019.06.021
• Erhardt, A.M., C.E. Reimers, D. Kadko, and A. Paytan, (2014). Records of trace metals in sediments from the Oregon hypoxic zone: Investigating the occurrence of hypoxia in the past hundreds to thousands of years. Chemical Geology, 382 32-43. DOI: 10.1016/j.chemgeo.2014.05.029
• Erhardt, A.M., H. Pälike, and A. Paytan, (2013). High-resolution record of export production in the eastern equatorial Pacific across the Eocene-Oligocene transition and relationships to global climatic records.  Paleoceanography 28 1-13. doi:10.1029/2012PA002347.

• *Avery, E., Samonina, O., Vyshenska, I., Fryar, A.E., Erhardt, A.M. 2022. Variation of tap-water isotope ratios and municipal water sources across Kyiv city, Ukraine. Discover Water. 2(1), 1-16. DOI: 10.1007/s43832-022-00021-x

• *Avery, E., Samonina, O., Kryshtop, L., Vyshenska, I., Fryar, A.E., Erhardt, A.M., 2022. Precipitation patterns in Ukraine as derived for water isotope analysis. Isotopes in Environmental and Health Studies. 1-22. DOI: 10.1080/10256016.2022.2131781