{"thcode":2,"term":{"code":1169,"name":"tiltmeter measurement","parent":375,"scope":"Determination of tiny changes in the slope angle or tilt of the ground in order to monitor deformation caused by moving magma. Instruments detect variations in a liquid level or in the position of a pendulum."},"uf":[{"name":"tiltmeter","usewith":false}],"bt":[{"code":375,"name":"field inventory and monitoring","parent":376,"scope":"Repeated observation or sampling at a site, on a scheduled or event basis, for study and analysis.  In general, this category excludes sampling programs in which materials are obtained in the field and brought back to a laboratory for study and analysis."},{"code":376,"name":"field methods","parent":734,"scope":"Research procedures and instrumental means to measure, collect data and samples, and observe in the natural areas where the materials, phenomena, structures, or species being studied occur."},{"code":734,"name":"methods","parent":1,"scope":"Techniques, methods, procedures, or strategies for research, management, collection, or analysis of scientific information in USGS."},{"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":1050,"name":"seismology","parent":470,"scope":"Branch of earth sciences concerned with the study of earthquakes and man-induced seismic waves."},{"code":1289,"name":"volcanology","parent":464,"scope":"The branch of geology that deals with volcanism and the processes involved in magma flow and eruption through a vent in the earth's surface."}]}