RESOLVED VERSUS DETECTED THIN BEDS

Two terms used to describe the quality of a thin-bed image say that the bed is either resolved or detected. If a bed is resolved in zero-phase seismic data, then both the top and bottom boundaries of the bed can be identified as a peak and/or trough in the seismic response, and the bed thickness can be measured in terms of the two-way seismic traveltime across the bed. If the bed creates a seismic reflection event, but the top and bottom boundaries of the bed are so close together that they cannot both be positioned at a peak and/or a trough in zero-phase data, then the bed is said to be detected, not resolved. The thickness of a detected bed must be inferred from the amplitude behavior of its reflection waveshape because its thickness cannot be measured directly in terms of a two-way traveltime difference between a peak and a trough.