Must Listen

Must Read

What Art Thinks

Pre-Millennialism

Today's Headlines

  • Sorry... Not Available
Man blowing a shofar

Administrative Area





Locally Contributed...

Audio

Video

Special Interest

Daily News
19940
“Triple Swarm of Earthquakes Shakes Yellowstone”
by KOMOnews.com   
September 23rd, 2013
130922_old_faithful_660

Until recently, Bob Smith had never witnessed two simultaneous earthquake swarms in his 53 years of monitoring seismic activity in and around the Yellowstone Caldera.

Now, Smith, a University of Utah geophysics professor, has seen three swarms at once.

“It’s very remarkable,” Smith said. “How does one swarm relate to another? Can one swarm trigger another and vice versa?”

Because concurrent swarms have never been detected in the past, the answers aren’t in yet, Smith said. The geophysicist said he “wouldn’t doubt” if at least two of the events were related.

Temblors from the three quake swarms mostly hit in three areas: Lewis Lake, the Lower Geyser Basin and the northwest part of Norris Geyser Basin.

The largest earthquake shook the ground near Old Faithful Geyser on Sept. 15.

The epicenter of the magnitude 3.6 quake, the largest in Yellowstone in about a year, was just 6 miles to the north of Old Faithful.

“Generally speaking it needs to be 3.0 or higher for individuals to feel it,” Yellowstone National Park spokesman Al Nash told the Jackson Hole News & Guide. “This one was somewhat stronger than that and it was in an area where a lot of people are.”

Yellowstone’s recent earthquake swarms started on Sept. 10 and were shaking until about 11:30 a.m. Sept. 16.

“A total of 130 earthquakes of magnitude 0.6 to 3.6 have occurred in these three areas, however, most have occurred in the Lower Geyser Basin,” a University of Utah statement said. “Notably much of seismicity in Yellowstone occurs as swarms.”

Including smaller events that have not been verified, there were many more quakes, Smith said.

The recent swarms produced roughly four quakes that were large enough to feel.

The first, a magnitude 3.5, struck Sept. 13 about 17 miles northeast of West Yellowstone, Mont. Then, in the early hours Sept. 15, two quakes, a magnitude 3.2 and magnitude 3.4, were detected in quick succession at 5:10 and 5:11 a.m., about 15 miles southeast of West Yellowstone. The magnitude 3.6 that marked the peak of the swarm struck nearby about 4 1/2 hours later.

go back button