Translations:Dictionary:In-seam methods/1/en

{{#category_index:I|in-seam methods}} Use of channel waves (q.v.) to investigate changes (such as interruptions by faults and washouts in coal seams) in a layer with lower velocity than underlying and overlying beds, such as coal measures. Both source and receivers are located in the layer and both reflection (where receivers are near the source in the same gallery) and transmission (where sources and receivers are in different galleries) techniques are used. See Sheriff and Geldart (1995, 483–486).