About: http://webisa.webdatacommons.org/186979896

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	How the isotopes vary over time can be measured by looking at such things as tree rings, which absorb carbon-14, and ice cores, which accumulate beryllium-10.
http://www.w3.org/ns/prov#wasQuotedFrom	washingtonpost.com