Marine reservoir effect

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The marine reservoir effect is a phenomenon affecting radiocarbon dating. Because much of the carbon consumed by organisms in the ocean is older than that consumed by organisms on land, samples from marine life and from organisms that consumed a lot of sea-based foods while alive may appear older when tested than they truly are. [1] It is necessary to account for changes in the Earth's oceans to correct for the marine reservoir effect. [2] The level of the effect on a particular sample varies significantly, depending on the body of water, and more locally on depths, upwelling currents, and freshwater discharges. [3]

Typically, affected radiocarbon dates appear c. 400 14C years older than they would if unaffected. But the effect is highly variable in space and time, and can reach 800 to 1200 14C years in Arctic regions. [2] In 2013, archaeologists at the Gottorp Castle Museum tested the effects of fish prepared in a newly made clay vessel on their ability to accurately measure carbon-14 in the clay pottery. After making the clay vessel fish was prepared in the vessel over a fire. The archaeologists made sure some of the fish stuck to the pot. The pot and some of the burnt crust at the bottom were tested which showed a Carbon-14 14C age of 700 years old. Felix Riede estimated at the time the use of the Carbon-14 method maybe off by 2,000 years. [4]

Notable cases

Since its initial discovery in the 1980s, a Viking burial site in England confounded archeologists. It contained coins and other physical materials associated with the late 800s CE, the time of the Great Danish Army, but the radiocarbon dating placed the roughly 300 bodies at a variety of different dates spanning centuries. In February 2018, a team out of the University of Bristol published a study attributing this to the large amounts of sea-based foods eaten by Vikings and placed the burial site in the late 800s. [1] [5]

Related Research Articles

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<span class="mw-page-title-main">Carbon-14</span> Isotope of carbon

Carbon-14, C-14, 14
C or radiocarbon, is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons. Its presence in organic materials is the basis of the radiocarbon dating method pioneered by Willard Libby and colleagues (1949) to date archaeological, geological and hydrogeological samples. Carbon-14 was discovered on February 27, 1940, by Martin Kamen and Sam Ruben at the University of California Radiation Laboratory in Berkeley, California. Its existence had been suggested by Franz Kurie in 1934.

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The variation in the 14
C/12
C ratio in different parts of the carbon exchange reservoir means that a straightforward calculation of the age of a sample based on the amount of 14
C it contains will often give an incorrect result. There are several other possible sources of error that need to be considered. The errors are of four general types:

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References

  1. 1 2 University of Bristol (February 2, 2018). "Radiocarbon dating reveals mass grave did date to the Viking age". Eurekalert. Retrieved February 4, 2018.
  2. 1 2 Philippa Ascough; Gordon Cook; Andrew Dugmore (December 1, 2005). "Methodological approaches to determining the marine radiocarbon reservoir effect" (PDF). Progress in Physical Geography: Earth and Environment. 29 (4): 532–547. Bibcode:2005PrPG...29..532A. doi:10.1191/0309133305pp461ra. S2CID   13472555.
  3. ↑ "Marine Reservoir Effect, Corrections to Radiocarbon Dates". Carbon Dating Service, AMS Miami - Beta Analytic. 2015-04-16. Retrieved 2022-02-19.
  4. ↑ Neils Ebdrup (14 March 2013). "Fish corrupt Carbon-14 dating". Science Nordic. Retrieved 27 November 2020.
  5. ↑ Catrine L. Jarman; Martin Biddle; Tom Higham; Christopher Bronk Ramsey (February 2, 2018). "The Viking Great Army in England: new dates from the Repton charnel" (PDF). Antiquity. 92 (361): 183–199. doi: 10.15184/aqy.2017.196 . Retrieved February 2, 2018.
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