Sept 24, 2013: A series of small earthquakes have been shaking the scenery at Yellowstone National Park. Four of these tremors were strong enough for park visitors to feel.
“A total of 130 earthquakes of magnitude 0.6 to 3.6 have occurred in these three areas, however, most have occurred near the Lower Geyser Basin,” reported The Inquisitor. “Notably, much of the seismicity in Yellowstone occurs as swarms. The University of Utah Seismograph Stations continues to monitor Yellowstone earthquakes and will provide additional information if the earthquake swarm activity increases.”
An earthquake swarm is an occurrence in which many earthquakes strike the same area within a fairly short timespan. These swarms are frequently seen before volcanic eruptions.
It’s not common for earthquake swarms to occur simultaneously, although that is just what the recent Yellowstone events have done. Bob Smith, a geophysics professor at the University of Utah, said that the recent geological tremors have actually been three distinct swarms.
"It's very remarkable," Smith told the Jackson Hole News and Guide. "How does one swarm relate to another? Can one swarm trigger another and vice versa?"
Visitors to the Lewis Lake, Lower Geyser Basin and the northwest part of Norris Geyser Basin were more likely to feel the tremors, since that’s where the majority of the swarms hit. The strongest quake measured at 3.6, the highest magnitude event in Yellowstone in the past year. It struck roughly six miles from Old Faithful, close enough that geyser visitors felt the shake.
So far, officials guess that none of the quakes were strong enough to alter the geyser patterns.
"We know that a significant enough earthquake in the region has potential to alter geyser activity," said Al Nash Yellowstone National Park spokesman. "A strong enough earthquake, like the one that occurred out at Hebgen Lake in 1959, did change the interval of Old Faithful eruptions."