Quantcast
Get breaking news alerts via email

Click here to manage your alerts
(Courtesy photo) | Wikipedia user Mminc10 The Beehive Geyser erupts in Yellowstone National Park, which sits above a far bigger magma reservoir than was previously thought.
Swarm of earthquakes shakes Yellowstone
First Published Sep 22 2013 05:21 pm • Last Updated Sep 23 2013 12:50 pm

Jackson, Wyo. • 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.

Join the Discussion
Post a Comment

"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 (http://bit.ly/16aaX8K). "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."


story continues below
story continues below

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.

"They weren’t big earthquakes," Smith said, "but they were felt."

About half a dozen earthquakes are felt in Yellowstone in an average year, he said.

"This is pretty unusual, to be honest," Smith said.

None of the recent quakes, Nash said, were strong enough to cause damage or throw off the cycle of the Old Faithful geyser’s eruptions.

"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.

Next Page >


Copyright 2014 The Salt Lake Tribune. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Top Reader Comments Read All Comments Post a Comment
Click here to read all comments   Click here to post a comment


About Reader Comments


Reader comments on sltrib.com are the opinions of the writer, not The Salt Lake Tribune. We will delete comments containing obscenities, personal attacks and inappropriate or offensive remarks. Flagrant or repeat violators will be banned. If you see an objectionable comment, please alert us by clicking the arrow on the upper right side of the comment and selecting "Flag comment as inappropriate". If you've recently registered with Disqus or aren't seeing your comments immediately, you may need to verify your email address. To do so, visit disqus.com/account.
See more about comments here.
Staying Connected
Videos
Jobs
Contests and Promotions
  • Search Obituaries
  • Place an Obituary

  • Search Cars
  • Search Homes
  • Search Jobs
  • Search Marketplace
  • Search Legal Notices

  • Other Services
  • Advertise With Us
  • Subscribe to the Newspaper
  • Access your e-Edition
  • Frequently Asked Questions
  • Contact a newsroom staff member
  • Access the Trib Archives
  • Privacy Policy
  • Missing your paper? Need to place your paper on vacation hold? For this and any other subscription related needs, click here or call 801.204.6100.