Skip to main content Accessibility help
×
×
Home

Time-Dependent Factors Inherent in the Age Equation for Determining Residence Times of Groundwater Using 14C: A Procedure to Compensate for the Past Variability of 14C in Atmospheric Carbon Dioxide, with Application to the Wairau Deep Aquifer, Marlborough, New Zealand

  • Claude B Taylor (a1)

Abstract

The radiocarbon concentration of dissolved inorganic carbon in groundwater is most logically and completely represented as the product of 5 time-variable factors; these are mutually independent, and all must be considered and evaluated to determine a groundwater residence time. In the case of one factor, the 14C/(12C+13C) ratio of atmospheric CO2, its time variability can be side-stepped by assuming it to be constant at the pre-bomb 1950 value, and assigning an apparent half-life in the radioactive decay term. Apparent half-lives are calculated here for 5 separate periods extending back to 24,000 BP, working from the INTCAL98 atmospheric calibration. This approach can be extended further back in time when the necessary atmospheric calibrations are updated with greater certainty. The procedure is applied to the recently-explored Wairau Deep Aquifer, underlying central areas of the coastal Wairau Plain, Marlborough. The evolution of dissolved inorganic carbon concentration for this river-recharged groundwater is apparent from distinct trends in 13C, and is confirmed by hydrochemical modelling. Extension to the 14C concentrations yields minimum/maximum limits for groundwater residence times to 3 wells. In all 3 cases, the maximum is uncertain due to present uncertainty of the apparent half-life applicable before 24,000 BP. Residence times for the 2 wells closest to the recharge area are at least 17,400 yr, while that for a well further down the aquifer is at least 38,500 yr. Recharge, therefore, occurred during the Otiran glaciation, while the present-day near-surface fluvioglacial deposits of the Wairau Plain were accumulating. Drawdown-recovery records over 3 yr indicate a permeable connection to compensating recharge, enabling limited exploitation for vineyard irrigation.

    • Send article to Kindle

      To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

      Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

      Find out more about the Kindle Personal Document Service.

      Time-Dependent Factors Inherent in the Age Equation for Determining Residence Times of Groundwater Using 14C: A Procedure to Compensate for the Past Variability of 14C in Atmospheric Carbon Dioxide, with Application to the Wairau Deep Aquifer, Marlborough, New Zealand
      Available formats
      ×

      Send article to Dropbox

      To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

      Time-Dependent Factors Inherent in the Age Equation for Determining Residence Times of Groundwater Using 14C: A Procedure to Compensate for the Past Variability of 14C in Atmospheric Carbon Dioxide, with Application to the Wairau Deep Aquifer, Marlborough, New Zealand
      Available formats
      ×

      Send article to Google Drive

      To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

      Time-Dependent Factors Inherent in the Age Equation for Determining Residence Times of Groundwater Using 14C: A Procedure to Compensate for the Past Variability of 14C in Atmospheric Carbon Dioxide, with Application to the Wairau Deep Aquifer, Marlborough, New Zealand
      Available formats
      ×

Copyright

References

Hide All
Beck, JW, Richards, DA, Edwards, RL, Silverman, BW, Smart, PA, Donahue, DJ, Herrara-Osterheld, S, Burr, GS, Calsoyas, L, Jull, AJT, Biddulph, D. 2001. Extremely large variations of atmospheric 14C concentration during the last glacial period. Science 292:2453–8.
Brown, LJ. 1981a. Late Quaternary geology of the Wairau Plain, Marlborough, New Zealand. New Zealand Journal of Geology and Geophysics 24:477–90.
Brown, LJ. 1981b. Water well data, Northern Marlborough. New Zealand Geological Survey Report NZGS93. 126 p.
Coplen, TB. 1994. Reporting of stable hydrogen, carbon and oxygen abundances. Pure and Applied Chemistry 66:2423–44.
Craig, H. 1965. The measurement of oxygen isotope paleotemperatures. In: Tongiorgi, E, editor. Stable Isotopes in Oceanographic Studies and Paleotemperatures. Pisa: Consiglio Nazionale delle Recherche, Laboratorio di Geologia Nucleare, Pisa. p 161–82.
Cunliffe, JJ. 1988. Water and Soil Resources of the Wairau. Water Resources Vol. 2. Blenheim: Marlborough Catchment Board and Regional Water Board. 107 p.
Kitigawa, H, van der Plicht, J. 1998. Atmospheric radiocarbon calibration to 45,000 yr BP: late glacial fluctuations and cosmogenic isotope production. Science 279:1187–90.
Rae, SN, editor. 1987. Water and Soil Resources of the Wairau. Water Resources Vol. 1. Blenheim: Marlborough Catchment Board and Regional Water Board. 301 p.
Salinger, MJ. 1988. New Zealand climate: past and present. In: Climate Change—The New Zealand Response. Proceedings of a workshop in Wellington, 29–30 March 1988. New Zealand Ministry for the Environment. p 1724.
Stuiver, M, Reimer, P, Bard, E, Beck, JW, Burr, GS, Hughes, KA, Kromer, B, McCormac, G, van der Plicht, J, Spurk, M. 1998. INTCAL98 radiocarbon age calibration 24,000–0 cal BP. Radiocarbon 40(3):1041–83.
Stuiver, M, Polach, HA. 1977. Reporting of 14C data. Radiocarbon 19(3):355–63.
Suggate, RP. 1965. Late pleistocene geology of the northern part of the South Island, New Zealand. New Zealand Geological Survey Bulletin 77. 91 p.
Suggate, RP. 1985. The glacial/interglacial sequence of north Westland, New Zealand. New Zealand Geological Survey Record 7. 22 p.
Taylor, CB. 1968. A comparison of tritium and strontium-90 fallout in the Southern Hemisphere. Tellus 20:559–76.
Taylor, CB, Roether, W. 1982. A uniform scale for reporting low-level tritium measurements in water. International Journal of Applied Radiation and Isotopes 33:377–82.
Taylor, CB. 1990. Stable isotopic concentrations of monthly precipitation samples collected in New Zealand and Rarotonga. Physical Sciences Report 3, Department of Scientific and Industrial Research, Lower Hutt, New Zealand. 92 p.
Taylor, CB, Brown, LJ, Cunliffe, JJ, Davidson, PW. 1992. Environmental tritium and oxygen-18 applied in a hydrological study of the Wairau Plain and its contributing mountain catchments, Marlborough, New Zealand. Journal of Hydrology 138:269319.
Taylor, CB. 1994. Hydrology of the Poverty Bay flats aquifers, New Zealand: recharge mechanisms, evolution of the isotopic composition of dissolved inorganic carbon and ground water ages. Journal of Hydrology 158:151–85.
Taylor, CB, Fox, VJ. 1996. An isotopic study of dissolved inorganic carbon in the catchment of the Waimakariri River and deep ground water of the Canterbury Plains, New Zealand. Journal of Hydrology 186:181–90.
Taylor, CB. 1997. On the isotopic composition of dissolved inorganic carbon in rivers and shallow groundwater: a diagrammatic approach to process identification and a more realistic model of the open system. Radiocarbon 39(3):251–68.
Taylor, CB, Evans, CM. 1999. Isotopic indicators for groundwater hydrology in Taranaki, New Zealand. Journal of Hydrology 38:237–70.
Taylor, CB, Trompetter, VJ, Brown, LJ, Bekesi, G. 2001. The Manawatu aquifers, North Island, New Zealand: clarification of hydrogeology using a multidisciplinary tracer approach. Hydrological Processes 15: 3269–86.
Vogel, JC. 1970. Carbon-14 dating of groundwater. In: Isotope Hydrology. Vienna: International Atomic Energy Agency, Vienna Symposium Proceedings. p 225–39.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Radiocarbon
  • ISSN: 0033-8222
  • EISSN: 1945-5755
  • URL: /core/journals/radiocarbon
Please enter your name
Please enter a valid email address
Who would you like to send this to? *
×

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed