What is a bump in mining terminology?

In mining terminology, a bump refers specifically to bursts of coal caused by excessive pressure. This phenomenon occurs when the stress within the coal seam exceeds its strength, leading to a sudden release of energy and resulting in a violent ejection of coal and rock. These bursts can pose significant safety risks, including injury to workers and damage to mining equipment.

The other options, while related to mining and geological processes, do not accurately define a bump. The burial of coal layers refers to the geological process of coal deposits being covered by other earth materials over time. Leakage of gas within a mine is a different hazard related to the accumulation of potentially harmful gases, which involves ventilation and safety measures but not the concept of a bump. A shift in geological strata refers to changes in the arrangement of rock layers, which can affect mining operations but is separate from the specific occurrence described as a bump.