Application of carbon 14 dating
Ocean sediment C-14 data The Lamont-Doherty Earth Observatory of Columbia University has compiled 974 C-14 dates from 309 ocean sediments cores, covering the period from 40,000 years BP to the present worldwide. The USGS Bear Lake Project aims to create records of past climate change for the Bear Lake region,including changes in precipitation patterns during the last 10,000 years and how the size of Bear Lake has varied in the past, to assess the possibility of future flooding and drought.Much of the information presented in this section is based upon the Stuiver and Polach (1977) paper "Discussion: Reporting of C14 data". 1890 wood was chosen as the radiocarbon standard because it was growing prior to the fossil fuel effects of the industrial revolution.Carbon-14 is a radioactive isotope used to date organic material.Its consistent rate of decay allows the age of an object to be determined by the proportion of carbon-14 to other carbon isotopes. Carbon-14 is also used as a radioactive tracer for medical tests.This inconsistent amount of carbon-14 renders the test less accurate but opens up testing possibilities not available for older samples.For example, it is possible to determine the age of a person born after the 1940s using the carbon-14 content of teeth.Obviously, this activity is additional and must be removed from calculations.In order to make allowances for background counts and to evaluate the limits of detection, materials which radiocarbon specialists can be fairly sure contain no activity are measured under identical counting conditions as normal samples.
Because organisms stop taking in carbon-14 at death, the age of the material can be precisely determined by this ratio of carbon isotopes.According to Stuiver and Polach (1977), all laboratories should report their results either directly related to NBS Oxalic acid or indirectly using a sub-standard which is related to it.It is vital for a radiocarbon laboratory to know the contribution to routine sample activity of non-sample radioactivity.Carbon-14 dating is a way of determining the age of certain archeological artifacts of a biological origin up to about 50,000 years old.It is used in dating things such as bone, cloth, wood and plant fibers that were created in the relatively recent past by human activities.