Geysers maintain a delicate balance between water and steam. A slight change can upset an eruption. A pre-eruptive splash may trigger a major eruption or cause a delay. Man can also have this same effect. Coins, sticks, stones, handkerchiefs, or soap thrown into a Yellowstone thermal feature can cause it to erupt prematurely, or more likely, cause it to clog, wither, and die.
Earthquakes also play a major role in upsetting the delicate balance of geysers.
It measured 7.1 on the Richter scale, formed a twenty foot displacement, and carved a slab from a mountain side which dammed the Madison River. In Yellowstone thermal activity increased. Geysers began to erupt, some with new vigor. Dormant geysers awoke and hot pools surged with excess water. The earthquake also caused some geysers to decrease in activity and shut others off completely.