https://cdn.earthdata.nasa.gov/conduit/upload/5182/KeywordsCommunityGuide_Baseline_v1_SIGNED_FINAL.pdf 23.8 2026-04-29T10:52:37.449Z https://gcmd.earthdata.nasa.gov/KeywordViewer/scheme/sciencekeywords/096f466a-a86a-42ac-93f7-05a799910817 ISOTOPES Date=2024-10-24 User Id=tstevens Entity=WeightedRelation Operation=INSERT System Note=insert WeightedRelation New Value=id: null related concept uuid: a0358b3e-0926-4b17-8b32-c1b15a73cba5 relationship type: null relationship value: null generated by: null Date=2024-10-24 User Id=tstevens Entity=Definition Operation=UPDATE Field=reference System Note=update Definition Old Value=GISP2 Ice core (Greenland) and Climate Change: http://www.gisp2.sr.unh.edu/GISP2/MoreInfo/Ice_Cores_Past.html New Value=GISP2 Ice core (Greenland) and Climate Change: http://www.gisp2.sr.unh.edu/GISP2/MoreInfo/Ice_Cores_Past.html Date=2024-10-24 User Id=tstevens Entity=WeightedRelation Operation=INSERT System Note=insert WeightedRelation New Value=id: null related concept uuid: 7557eddd-db2a-4f39-b1e2-91162f4fc92e relationship type: null relationship value: null generated by: null Date=2024-10-24 User Id=tstevens Entity=WeightedRelation Operation=INSERT System Note=insert WeightedRelation New Value=id: null related concept uuid: 61f57065-8f47-45c7-8319-f6115153a6ad relationship type: null relationship value: null generated by: null Date=2024-10-24 User Id=tstevens Entity=WeightedRelation Operation=INSERT System Note=insert WeightedRelation New Value=id: null related concept uuid: 441ce068-91f2-4412-8893-c0096d8f9079 relationship type: null relationship value: null generated by: null Date=2024-10-24 User Id=tstevens Entity=WeightedRelation Operation=INSERT System Note=insert WeightedRelation New Value=id: null related concept uuid: 4d5f7ae1-3368-468b-825b-e72c1df24508 relationship type: null relationship value: null generated by: null Date=2024-10-24 User Id=tstevens Entity=WeightedRelation Operation=INSERT System Note=insert WeightedRelation New Value=id: null related concept uuid: f0d4b06b-c498-4760-bc92-877e28f3a098 relationship type: null relationship value: null generated by: null The isotopic record found in ice cores reveal direct information about the pastclimate. d18O (delta oxygen-18), 16O and 18O are isotopes of oxygen with slightdifferences in atomic weight. Depending on the temperature of evaporation andhow far the water has had to travel before it fell as snow, the ratio of 18O to16O will vary. This ratio, known as d18O, can be measured very accurately usinga mass spectrometer. Over short time scales the change in temperature fromsummer to winter produces a very clear oscillation in the 18O/16O ratio. Thisoscillation is used to determine the age of the core at different depths,simply by counting the oscillations. Over longer time periods, this ratioindicates the average temperature of the regions between the evaporation siteand the coring site. Investigators in Greenland and Antarctica are alsoanalyzing for the ratio of 1H/2H (Hydrogen to deuterium) which will allow evenfiner detail about source temperature and condensation history to be obtained. 2024-10-24 08:54:28.0