{"thcode":61,"term":{"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."},"uf":[],"bt":[{"code":400,"name":"field observation","parent":398,"scope":"scientific investigation of physical or biological features and processes in a natural setting."},{"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":479,"name":"seismic reflection profiling","parent":478,"scope":"technique for determining the composition and structure of subsurface earth materials based on the transmission and reflection of artificially induced seismic waves; in practice, the seismic waves are generated and received at a one location (in marine geophysical studies, a single ship)."},{"code":480,"name":"seismic refraction profiling","parent":478,"scope":"technique for determining the composition and structure of subsurface earth materials based on the transmission and refraction of naturally occurring or artificially induced seismic waves; in practice, the seismic waves are generated and received at different locations (in marine geophysical studies, two or more ships)."}],"rt":[{"code":734,"name":"geophysics","parent":639,"scope":"physics applied to the study of the Earth."}]}