{"thcode":2,"term":{"code":1721,"name":"magnetic storms","parent":451,"scope":"A period of time during which the earth's magnetic field varies rapidly.  During magnetic storms, satellite electronics can be damaged through the build up and subsequent discharge of static electric charges and astronauts and high-altitude pilots can be subjected to increased levels of radiation."},"uf":[{"name":"geomagnetic storms","usewith":false}],"bt":[{"code":451,"name":"geologic processes","parent":101,"scope":"All types of processes involving geological structures."},{"code":101,"name":"biological and physical processes","parent":1174,"scope":"All continuing activities, functions, and phenomena associated with organisms and non-living matter."},{"code":1174,"name":"topics","parent":1,"scope":"Themes, subjects, and concerns for which USGS information resources are relevant."},{"code":1,"name":"Categories","parent":null,"scope":"Thematic terms for categorizing information resources.  This thesaurus is intended to support finding and understanding scientific information."}],"nt":[],"rt":[{"code":531,"name":"hazards","parent":1174,"scope":"Potential dangers from both natural processes (e.g., earthquakes, floods, and climate change) and human impacts on the environment."},{"code":677,"name":"magnetic field (earth)","parent":287,"scope":"The magnetic region surrounding earth.  It is generated by the dipolar characteristic of earth's core whereby earth itself acts as a great spherical magnet with poles near, but not exactly at, the North and South poles."}]}