{"thcode":2,"term":{"code":1750,"name":"sinkhole formation","parent":353,"scope":"Localized collapse of the land surface usually due to erosion of the underlying materials.  Most commonly occurring in karst areas, but similar effects occur due to physical erosion in other terranes."},"uf":[],"bt":[{"code":353,"name":"erosion","parent":451,"scope":"The process whereby materials of the earth's crust are loosened, dissolved, or worn away and simultaneously moved from one place to another."},{"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":2031,"name":"karst","parent":626,"scope":"Landscape characterized by dissolution features in carbonate or evaporite terranes, often containing caves and sinkholes."}]}