1. n. [Geophysics]

The lower boundary of the near-surface, low-velocity zone in which rocks are physically, chemically, or biologically broken down, in some cases coincident with a water table. Static corrections to seismic data can compensate for the low velocity of the weathered layer in comparison with the higher-velocity strata below.

See related terms: first break,  ghost,  static correction,  velocity,  weathering