In coal mining areas, when seams are not fully removed, the edges left behind can cause intense tremors when mining continues nearby. These tremors happen because the stress in the rock gets unsettled. Even if mining is happening far away, it can still shake things up near these leftover edges. Researchers studied coal seam 408 and found that mining activities can mess with stress levels near the remnants of other coal seams, even if they're quite deep down. This disruption in stress balance is what leads to strong mining-related tremors.