Geothermal Energy Resource Characterization and Development

Geothermal energy is a renewable resource that relies on Earth’s internal heat to generate electricity. With post-doctoral expertise in geothermal geochemistry, our subject matter experts apply industry-proven geochemistry methods to assist development projects throughout the world. We recognize that each situation has unique characteristics. Our team is equipped with cutting-edge geochemical modeling tools and has experience in developing geochemical techniques to suit each situation. Our portfolio of experience includes project work on prospects located in the western USA, Indonesia, the Philippines, the Caribbean, and Central America. We support projects during all stages of development, including resource characterization through to scaling potential assessments. We partner with organizations to identify and implement sampling programs that generate quality data, providing confidence to our clients when making critical decisions. Our project experience and expertise includes:

  • Due diligence review of geochemistry resource characterization studies.
  • Conceptual model development.
  • Exploration sampling program development.
  • Scaling prediction assessments.
  • Water quality assessments.
  • Traditional geothermometer and multi-component geothermometry interpretation.
  • Environmental compliance and contamination assessments and mitigation.

Relevant Staff Publications:

  1. Herman, S., A. Fowler, and S. Alexander. (2026, June 8–11). Multicomponent thermodynamic geothermometry and geochemical modeling of submarine hot springs in northern Dominica. World Geothermal Congress, Calgary, Canada.
  2. Herman, S., A. Fowler, and S. Alexander. (2025). Multicomponent Thermodynamic Geothermometry of Submarine Hot Springs in Northern Dominica. Latin American Geothermal Congress, El Salvador.
  3. Alexander, K., J. Gilliland, S. Herman, and A. Fowler. (2025, November 11–13). Geochemical Assessment of the Picard River Geothermal Prospect in Northern Dominica. Proceedings 47th New Zealand Geothermal Workshop, Rotorua, New Zealand.
  4. Alexander, K., P. Aguilar, D. Steven, J. Gilliland, S. Herman, and A. Fowler. (2025). Resource Assessment of the Picard River Geothermal Prospect in Northern Dominica. GRC Transactions, 49.
  5. Ong, C., A. Fowler, W.E. Seyfried Jr, T. Sun, and Q. Fu. (2021, September). Organic compounds in vent fluids from Yellowstone Lake, Wyoming. Organic Geochemistry, 159, 104275. https://doi.org/10.1016/j.orggeochem.2021.104275
  6. Tudor, A., A. Fowler, D.I. Foustoukos, B. Moskowitz, L. Wang, C. Tan, and W.E. Seyfried Jr. (2021, June). Geochemistry of vapor-dominated hydrothermal vent deposits in Yellowstone Lake, Wyoming. Journal of Volcanology and Geothermal Research, 414, 107231. https://doi.org/10.1016/j.jvolgeores.2021.107231
  7. Zierenberg, R.A., G.Ó. Friðleifsson, W.A. Elders, P. Schiffman, and A. Fowler. (2021, November 19). Active basalt alteration at supercritical conditions in a seawater‐recharged hydrothermal system: IDDP‐2 drill hole, Reykjanes, Iceland. Geochemistry, Geophysics, Geosystems, 2022. https://doi.org/10.1029/2021GC009747
  8. Tan, C., A. Fowler, A. Tudor, and W.E. Seyfried Jr. (2020, November 1). Heat and mass transport in sublacustrine vents in Yellowstone Lake, Wyoming: In-situ chemical and temperature data documenting a dynamic hydrothermal system. Journal of Volcanology and Geothermal Research, 405. https://doi.org/10.1016/j.jvolgeores.2020.107043
  9. Friðleifsson, G.Ó., W.A. Elders, R.A. Zierenberg, A. Fowler, T.B. Weisenberger, K.G. Mesfin, Ó. Sigurðsson, S. Níelsson, G. Einarsson, F. Óskarsson, and E.Á. Guðnason. (2020). The Iceland Deep Drilling Project at Reykjanes: Drilling into the root zone of a black smoker analog. Journal of Volcanology and Geothermal Research, 391. https://doi.org/10.1016/j.jvolgeores.2018.08.013
  10. Fowler, A., Q. Liu, Y. Huang, C. Tan, M. Volk, W.C. Shanks III, and W. Seyfried Jr. (2019, November 15). Pyrite δ34S and Δ33S constraints on sulfur cycling at sublacustrine hydrothermal vents in Yellowstone Lake, Wyoming, USA. Geochimica et Cosmochimica Acta, 265. https://doi.org/10.1016/j.gca.2019.09.004
  11. Fowler, A., C. Tan, K. Luttrell, A. Tudor, P. Scheuermann, W.C. Shanks III, and W. Seyfried Jr. (2019, November 15). Geochemical heterogeneity of sublacustrine hydrothermal vents in Yellowstone Lake, Wyoming. Journal of Volcanology and Geothermal Research, 386. https://doi.org/10.1016/j.jvolgeores.2019.106677
  12. Fowler, A., C. Tan, P. Scheuermann, and W. Seyfried Jr. (2019, June 20). Titanium hydrothermal reactors for redox-sensitive experimentation at extreme T-P conditions: The effect of dissolved salt on H2 activity-concentration relations. Chemical Geology, 515, 87–93. https://doi.org/10.1016/j.chemgeo.2019.04.008
  13. Fowler, A., C. Cino, C. Tan, P. Scheuermann, M.R. Volk, W.C. Shanks III, and W. Seyfried Jr. (2019, March 1). Vapor-driven sublacustrine vents in Yellowstone Lake, Wyoming, USA. Geology, 47(3), 223–226. https://doi.org/10.1130/G45577.1
  14. Fowler, A., R.A. Zierenberg, M.H. Reed, and J. Palandri. (2018, January 1). Rare earth element systematics in boiled fluids from basalt-hosted geothermal systems. Geochimica et Cosmochimica Acta, 244, 129–154. https://doi.org/10.1016/j.gca.2018.10.001
  15. Friðleifsson, G.Ó., W.A. Elders, R.A. Zierenberg, A. Fowler, T.B. Weisenberger, K.G. Mesfin, Ó. Sigurðsson, S. Níelsson, G. Enarsson, G. Guðnason, F. Óskarsson, E. Á. Guðnason, H. Tulinius, K. Hokstad, G. Benoit, F. Nono, D. Loggia, F. Parat, S.B. Cichy, D. Escobedo, and D. Manprice. (2020, February). The Iceland Deep Drilling Project at Reykjanes: Drilling into the root zone of a black smoker analouge. Journal of Volcanology and Geothermal Research, 391. https://doi.org/10.1016/j.jvolgeores.2018.08.013
  16. Fowler, A., C. Ferguson, C. Cantwell, R.A. Zierenberg, J. McClain, N. Spycher, and P. Dobson. (2018, March 15). A conceptual geochemical model of the geothermal system at Surprise Valley, California. Journal of Volcanology and Geothermal Research, 353, 132–148. https://doi.org/10.1016/j.jvolgeores.2018.01.019
  17. Dobson, P., E. Gasperikova, N. Spycher, N. Lindsey, T.R. Guo, W.S. Chen, C.H. Liu, C. Wang, S. Chen, and A. Fowler. (2018). Conceptual model of the Tatun geothermal system, Taiwan. Geothermics, 74, 273–297. https://doi.org/10.1016/j.geothermics.2018.01.001
  18. Zierenberg, R., A. Fowler, G.Ó. Friðleifsson, W.A. Elders, and T.B. Weisenberger. (2017) Preliminary description of rocks and alteration in IDDP-2 drill core samples recovered from the Reykjanes geothermal system, Iceland. GRC Transactions, 41. https://publications.mygeoenergynow.org/grc/1033823.pdf
  19. Friðleifsson, G.Ó., W.A. Elders, R.A. Zierenberg, A. Stefánsson, A. Fowler, T.B. Weisenberger, and B.S. Harðarson. (2017, November 30). The Iceland Deep Drilling Project 4.5 km deep well, IDDP-2, in the Reykjanes geothermal field in SW Iceland has successfully reached its supercritical target. Scientific Drilling, 23, 1–12. https://doi.org/10.5194/sd-23-1-2017
  20. Fowler, A., N. Spycher, R.A. Zierenberg, and C. Cantwell. (2017, May). Identification of blind geothermal resources in Surprise Valley, CA, using publicly available groundwater well water quality data. Applied Geochemistry, 80, 24–48. https://doi.org/10.1016/j.apgeochem.2017.03.001
  21. Siler, D., Y. Zhang, N. Spycher, P. Dobson, J. McClain, E. Gasperikova, R. Zierenberg, P. Schiffman, C. Ferguson, A. Fowler, and C. Cantwell. (2017, September). Play-fairway analysis for geothermal resources and exploration risk in the Modoc Plateau region. Geothermics, 69, 15–33. https://doi.org/10.1016/j.geothermics.2017.04.003
  22. Fowler, A. and Zierenberg, R.A. (2016, November 7). Elemental changes and alteration recorded by basaltic drill core samples recovered from in-situ temperatures up to 345°C in the active, seawater-recharged Reykjanes geothermal system, Iceland. Geochemistry, Geophysics, Geosystems, 17. https://doi.org/10.1002/2016GC006595
  23. Fowler, A. and Zierenberg, R.A. (2016). Geochemical bias in drill cutting samples versus drill core samples returned from the Reykjanes Geothermal System, Iceland. Geothermics, 62, 48–60. https://doi.org/10.1016/j.geothermics.2016.02.007
  24. Fowler, A. and Zierenberg, R. (2015, April 19–25). Rare earth element concentrations in geothermal fluids and epidote from the Reykjanes geothermal system, Iceland. Proceedings of the World Geothermal Congress, Melbourne, Australia.
  25. Fowler, A., R.A. Zierenberg, P. Schiffman, N. Marks, and G.Ó. Friðleifsson. (2015, September 1). Evolution of fluid-rock interaction in the Reykjanes geothermal system, Iceland: Evidence from Iceland Deep Drilling Project core RN-17B. Journal of Volcanology and Geothermal Research, 302, 47–63. https://doi.org/10.1016/j.jvolgeores.2015.06.009
  26. Fowler, A., C. Cantwell, N. Spycher, P. Dobson, D. Siler, M. and Kennedy. (2015, January 26–28). Integrated geochemical investigations of Surprise Valley thermal springs and cold well waters. Proceedings of the Fortieth Workshop on Geothermal Reservoir Engineering, Stanford University, Stanford, California.
  27. McClain, J., P. Dobson, C. Cantwell, M. Conrad, C. Ferguson, A. Fowler, E. Gasperikova, W. Glassley, S. Hawkes, P. Schiffman, D. Siler, N. Spycher, C. Ulrich, Y. Zhang, R. Zierenberg. (2015). Geothermal play fairway analysis of potential geothermal resources in NE California, NW Nevada, and Southern Oregon: A transition between extension-hosted and volcanically-hosted geothermal fields. GRC Transactions, 39, 739–742. https://publications.mygeoenergynow.org/grc/1032214.pdf
  28. Cantwell, C. and Fowler, A. (2014, February 24–26). Fluid geochemistry of the Surprise Valley geothermal system. Proceedings of the Thirty-Ninth Workshop on Geothermal Reservoir Engineering, Stanford University, Stanford, California.

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