{"thcode":61,"term":{"code":400,"name":"field observation","parent":398,"scope":"scientific investigation of physical or biological features and processes in a natural setting."},"uf":[{"name":"field methods","usewith":false}],"bt":[{"code":398,"name":"research method","parent":1,"scope":null},{"code":1,"name":"Marine Realms Information Bank (MRIB) keyword categories","parent":null,"scope":null}],"nt":[{"code":417,"name":"Global Positioning System (GPS) observations","parent":400,"scope":"the use of satellite signals from the Global Positioning System to determine the precise location of a terrestrial receiver."},{"code":401,"name":"acoustic methods","parent":400,"scope":" measurement of sound propagation in a given medium (such as water) for ranging or acoustical studies."},{"code":447,"name":"altimetry","parent":400,"scope":"used for all instruments and techniques that determine altitude, either directly or remotely, including (but not limited to) pressure altimeters, radar altimeters, GPS, and LIDAR."},{"code":405,"name":"biological observations","parent":400,"scope":"scientific investigation of organisms in a natural setting."},{"code":408,"name":"chemical tracer studies","parent":400,"scope":"the introduction of an easily detected substance into a natural physical or biological system for the purpose of documenting its movement (or other changes) with time."},{"code":409,"name":"controlled burn experiments","parent":400,"scope":"prescribed burning of selected tracts of land to understand the behavior of wildfires or to preempt large wildfires."},{"code":410,"name":"diving","parent":400,"scope":"used for all methods of direct underwater observation by humans."},{"code":411,"name":"electrical resistivity measurements","parent":400,"scope":"borehole measurements to characterize in situ earth materials and pore fluids by their resistance to the flow of electrical currents."},{"code":412,"name":"electromagnetic conductivity measurements","parent":400,"scope":"used for shallow underground imaging techniques based on variations in the electrical conductance of earth materials."},{"code":413,"name":"excavation","parent":400,"scope":"exposing underground earth materials and structures for inspection, typically by trenching."},{"code":414,"name":"fossil collecting and description","parent":400,"scope":"the removal and documentation of fossils from any natural setting, typically for additional study in the laboratory."},{"code":415,"name":"gamma ray logging","parent":400,"scope":"measurements of natural gamma radiation emitted by the earth materials in a borehole."},{"code":448,"name":"geodetic measurements","parent":400,"scope":"field studies of the Earth's shape, dimensions, and gravitational field."},{"code":416,"name":"geotechnical measurements","parent":400,"scope":"the use of standardized field tests to determine the engineering properties of earth materials."},{"code":418,"name":"gravimetry","parent":400,"scope":"measurement of the gravitational field at specific locations, yielding data that can be analyzed for a variety of scientific purposes."},{"code":419,"name":"heat flow observations","parent":400,"scope":"measurement of the dissipation of internal heat at the Earth's surface."},{"code":420,"name":"hydraulic conductivity observations","parent":400,"scope":"measurements to quantify the ability of fluids to move through porous earth materials."},{"code":421,"name":"hydrologic observations","parent":400,"scope":"used broadly for observations of atmospheric, surface, and subsurface water."},{"code":426,"name":"magnetic field observations","parent":400,"scope":"measurement of the Earth's magnetic field at a specific location; often used to detect magnetic anomalies that reflect the nature and distribution of subsurface earth materials."},{"code":427,"name":"mapping","parent":400,"scope":"in addition to traditional cartographic methods, this term is used for all field activities that document spatial relationships of scientific interest."},{"code":430,"name":"meteorological observations","parent":400,"scope":"field observations of weather conditions, including but not limited to temperature, humidity, atmospheric pressure, wind, and precipitation."},{"code":437,"name":"oceanographic observations","parent":400,"scope":"used for field observations related to all aspects of oceanography: physical, chemical, and biological; may also be used for field studies of freshwater bodies that use oceanographic techniques."},{"code":445,"name":"photography","parent":400,"scope":"limited to photography for scientific purposes."},{"code":449,"name":"remote sensing","parent":400,"scope":"generally used for the acquisition of images or other data from aircraft or satellites; also used for ground-based systems for collecting data at a distance."},{"code":462,"name":"sampling","parent":400,"scope":"used for the collection of physical samples and also images that document physical conditions."},{"code":478,"name":"seismic methods","parent":400,"scope":"the study of naturally occurring or artificially induced seismic waves, generally for one of two purposes: 1) understanding the nature and cause of seismic activity (e.g., earthquakes), or 2) understanding the properties of the earth materials through which the seismic waves have passed."},{"code":481,"name":"seismographic measurements","parent":400,"scope":"the measurement of transient ground motion attributed to seismic waves."},{"code":482,"name":"stratigraphic characterization and correlation","parent":400,"scope":"field observation of sedimentary rock strata at two or more locations, with the goal of establishing their physical continuity or temporal equivalence."},{"code":483,"name":"underwater vehicle observations","parent":400,"scope":"direct observation of underwater features using submersibles (manned or remotely operated)."},{"code":484,"name":"video observation","parent":400,"scope":"video documentation of natural features and processes."}],"rt":[]}