Geothermal Springs is a Renewable Resource

Geothermal activities around the world provide opportunities for oil and gas exploration, groundwater-sourced heating and cooling, and water pollution assessment.

Uniform Geothermal Gradient

Location: Qiongdongnan and Pearl River Mouth Basins, China

Yuan et al. used a uniform geothermal gradient to find temperature distribution. Oil and gas exploration surveys measure the thermal conductivity, radioactive heat production, geothermal gradient values and heat flow values.

Geothermal Resources

Location: Khachmaz and Sabir-Oba, Azerbaijan

Nabiye et al. measured temperature and pressure to calculate the following properties in characterizing geothermal resources:

• From temperature (T) and pressure (P):
  • Empirical correlation for density (ρ),
    • Isothermal compressibility (β_T),
    • Isobaric thermal expansibility (β_P), and
    • Difference in isobaric and isochoric heat capacities (C_P and C_V).

  Open-Loop Well-Doublet Schemes

  Banks assessed thermal plume effects from open-loop well-doublets. Well-doublets abstract water from the ground, perform heat transfer and injects used water into the ground. This temperature difference in water affects sensitive species and pollution to downstream users. Backwash injected water may mix with cold abstracted water over time to render the system useless. The open-loop system is an improvement on the original idea to make the scheme economically viable.

  Groundwater Systems

  Location: Cape Verde, West Africa

  Heilweil, Solomon, Gingerich, and Verstraeten investigated groundwater systems using stable radioactive isotopes. The water source was rain at high elevation. Geothermal activity did not affect the groundwater. Seven sites had water residence time for over half a century, such as the Ribeira Faj Basin at So Nicolau Island. Mosteiro Basin at Fogo Island and Ribeira Paul Basin at Santo Anto Island were found to be at risk from surface contamination and salination.

  The Urban Heat Island Effect

  Location: Istanbul, Turkey

  Urbanization causes elevated groundwater temperature. The sources could be heat loss and energy absorbed by developed land. Yalcin and Yetemen found South Istanbul groundwater temperature 3.5^oC higher than North Istanbul. They suggested geothermal energy using heat pump for recovery is one of the alternative to fossil fuel energy.

  Geothermal Drainage

  Location: Yellowstone National Park

  Planer-Friedrich, Fisher, Hollibaugh, Suss, and Wallschlager found microorganisms related to Thermocrinis rubber breaks down trithioarsenate to arsenate in the alkaline, sufide-containing geothermal springs. This microbial catalysis is 40-500 times faster than laboratory oxidation. This natural phenomenon could be used to develop arsenic remediation.

  References

  
  

  Yuan, Y., Zhu, W.L., Mi, L.J., Zhang, G.C., Hu, S.B. & He, L.J. (2009). "Uniform geothermal gradient" and heat flow in the Qiongdongnan and Pearl River Mouth Basins of the South China Sea. Marine and Petroleum Geology, 26(7), 1152-1162. DOI:10.1016/j.marpetgeo.2008.08.008

  
  

  Nabiyev, N.D., Bashirov, M.M., Safarov, J.T., Shahverdiyev, A.N. & Hassel, E.P. (2009). Thermodynamic properties of the geothermal resources (Khachmaz and Sabir-Oba) of Azerbaijan. Journal of Chemical and Engineering Data, 54(6), 1799-1806. DOI:10.1021/je800840m

  
  

  Banks, D. (2009). Thermogeological assessment of open-loop well-doublet schemes: A review and synthesis of analytical approaches. Hydrogeology Journal, 17(5), 1149-1155. DOI:10.1007/s10040-008-0427-6

  
  

  Heilweil, V.M., Solomon, D.K., Gingerich, S.B. & Verstraeten, I.M. (2009). Oxygen, hydrogen and helium isotopes for investigating groundwater systems of the Cape Verde Islands, West Africa. Hydrogeology Journal 17(5) 1157-1174. DOI:10.1007/s10040-009-0434-2

  
  

  Yalcin, T. & Yetemen, O. (2009). Local warming of groundwaters caused by the urban heat island effect in Istanbul, Turkey. Hydrogeology Journal, 17(5), 1247-1255. DOI: 10.1007/s10040-009-0474-7

  
  

  Planer-Friedrich, B., Fisher, J.C., Hollibaugh, J.T., Suss, E. & Wallschlager, D. (2009). Oxidative transformation of trithioarsenate along alkaline geothermal drainages: Abiotic versus microbially mediate processes. Geomicrobiology Journal, 26(5), 339-350. DOI:10.1080/01490450902755364
  
  Inspiration: Hot Springs Around the World from gosmiley.com