https://cdn.earthdata.nasa.gov/conduit/upload/5182/KeywordsCommunityGuide_Baseline_v1_SIGNED_FINAL.pdf 23.7 2026-04-15T10:53:30.610Z https://gcmd.earthdata.nasa.gov/KeywordViewer/scheme/sciencekeywords/65ae8ab2-489b-44bf-bf5b-43cf957b70c0 MAGNETIC ANOMALIES Date=2013-02-18 User Id=tbs1979 Entity=BroaderRelation Operation=DELETE User Note=Move Concepts System Note=delete broader relation Old Value=MAGNETIC ANOMALIES [65ae8ab2-489b-44bf-bf5b-43cf957b70c0,63569] - GEOMAGNETISM [910013d7-1e6a-4d1a-9921-be32d792a290,61749] Date=2013-03-11 User Id=tbs1979 Entity=Definition Operation=UPDATE Field=reference System Note=update Definition New Value=U.S. Geological Survey Date=2013-03-11 User Id=tbs1979 Entity=Definition Operation=UPDATE Field=text System Note=update Definition Old Value=Pertaining to the use of variances in the Earth's magnetic field to determine the location of subsurface structures. New Value=Local variation in the Earth's magnetic field resulting from variations in the chemistry or magnetism of the rocks. Mapping of variation over an area is valuable in detecting structures obscured by overlying material. The magnetic variation in successive bands of ocean floor parallel with mid-ocean ridges is important evidence supporting the theory of seafloor spreading, central to plate tectonics. Date=2013-02-18 User Id=tbs1979 Entity=BroaderRelation Operation=INSERT User Note=Move Concepts System Note=add broader relation New Value=MAGNETIC ANOMALIES [65ae8ab2-489b-44bf-bf5b-43cf957b70c0,63569] - MAGNETIC FIELD [204b482b-449b-42c9-a5bb-f6da42bee3a4,63915] Local variation in the Earth's magnetic field resulting from variations in the chemistry or magnetism of the rocks. Mapping of variation over an area is valuable in detecting structures obscured by overlying material. The magnetic variation in successive bands of ocean floor parallel with mid-ocean ridges is important evidence supporting the theory of seafloor spreading, central to plate tectonics. 2013-03-11 15:06:32.0