“We know that a significant enough earthquake in the region has potential to alter geyser activity,” the spokesman said. “A strong enough earthquake, like the one that occurred out at Hebgen Lake in 1959, did change the interval of Old Faithful eruptions.”
That quake, a 7.3 to 7.5 on the Richter magnitude scale, caused nearly 300 features on the Yellowstone landscape to erupt, 160 of which had no previous record of geysers.
Smith traced the three recent earthquake swarms to the Hebgen Lake quake.
“These are a really related,” he said.
“We think that much of the seismicity is still aftershocks from that event in 1959. It can go on for hundreds of years.”
i did a lot of research on this once and if i remember correctly it takes something like 500 years for the chamber to fill with magma and there's no reason to believe this process has even started yet.