bump
n.— «Dreger said data from the blowout, or “bump” as it is known in mining parlance, showed the initial motion of the earth was the same, though smaller in force, to the initial collapse. He said that analysis confirmed that the mine collapse was triggered by shifting of rock in response to activity in the mine and not other seismic forces.» —“Seismic readings at Utah mine do not point to quake” by William M. Welch USA Today Aug. 28, 2007. (source: Double-Tongued Dictionary)