Earthquake swarm at Tellowstone NP

Hot Lava: The Planet’s Largest Supervolcano Setting Earthquake Swarm Records

A continuing earthquake swarm located over the monstrous Yellowstone caldera in the US state of Wyoming has now provided over 2,300 tremors since its June inception.

Sputnik,

4 September, 2017

According to instrument documentation, as of August 30, 2,357 earthquakes were recorded in the region around the Yellowstone supervolcano, the largest active caldera in North America, since the beginning of the swarm in early June.

Most of the temblors are in the range of magnitude 0 or 1, and many have been recorded at magnitude 2 or 3 — relatively light earthquakes — but it is the sheer number of events that has seismologists sitting up and taking notice.

Observing seismic activity at Yellowstone, Jamie Farrell, a research professor at the nearby University of Utah, suggested that the swarm was "nothing out of the ordinary" but "does occasionally have little bursts of activity that lasts for a few hours," cited by Newsweek

But while most of the quakes are small enough to go unnoticed by visitors to the popular US national park, the ongoing 2017 summer swarm is now been documented as one of the longest and largest since records began being kept, according to Yahoo news.

Only an October 1985 earthquake swarm at the legendary volcano was larger, lasting about three months and documenting over 3,000 earthquakes.

Earthquakes swarms do not necessarily signal a volcanic eruption in Yellowstone. But seismologists and scientists continue to keep an eye on the activity over

the enormous 1500-square-mile caldera, where bubbling magma lies a mere five to seven miles below the surface.

The last major eruption of the Yellowstone supervolcano, one of the Earth's largest, occurred some 640,000 years ago and ejected about 80,000 times the amount of airborne particulates — including ash — spewed by the deadly eruption of Mount St. Helens in 1980.

The US Geological Survey, however, shows the current volcano alert level in Yellowstone National Park to be normal, and displays the aviation color code as green, indicating no current threat to flights in the region.

Recently, a scientist with the Yellowstone Volcano Observatory, observed that "for magma to reach the surface a new vent needs to be created, which requires a lot of intense geological activity," according to Newsweek.

The scientist added that, "we would need to see considerably more and larger earthquakes, combined with contemporaneous ground deformation, steam explosions and changes in gas and heat discharge, prior to moving the [current green] alert level."

"None of that has occurred," he stated.

EARTHQUAKE SWARM WON'T STOP: 62 earthquakes have struck Southeast Idaho since Saturday evening

http://idahostatejournal.com/news/local/earthquakes-hit-southeast-idaho-in-three-hours/article_060cae26-3389-508b-be7c-ae852f81ffda.html

2 September, 2017

The strongest earthquake to hit the region in years as well as 61 smaller quakes occurred Saturday night to Sunday night in Southeast Idaho, startling tens of thousands of residents.

Authorities said it does not appear that the quakes have caused any injuries to people or damage to structures

The quakes were felt in Caribou County, where all 62 occurred, as well as in cities in northern Utah and throughout Southeast Idaho. It's unknown when the earthquake swarm will end. Earthquake swarms have been known to continue for weeks or even months.

In recent decades Southeast Idaho has seen infrequent instances in which one to three weak earthquakes occur near the Western Wyoming border. Local authorities say they cannot ever remember any earthquake swarm in Southeast Idaho that comes even close to the current series of temblors shaking the region.

Five of the quakes occurred early Sunday evening — the last being at 6:36 p.m. They were preceded by five quakes on Sunday afternoon, 19 on Sunday morning and 33 on Saturday night. All 62 of the quakes were reported by University of Utah Seismograph Stations.

Bannock County Sheriff Lorin Nielsen said he's been a law enforcement officer in Southeast Idaho for over 40 years and during that time there's never previously been so many earthquakes occurring in such a short time frame. He said at the most there have been up to three earthquakes that have occurred in short succession along the East Idaho-Western Wyoming border. The dozens of earthquakes that occurred from Saturday night through early Sunday evening are unprecedented, the sheriff said.

"I've never seen anything like this," Nielsen said. "My wife asked if we should leave the house."

The earthquakes occurred starting shortly before 6 p.m. Saturday. The second quake to strike was at 5:56 p.m. Saturday and it was the most powerful thus far. The quake was about 10 miles east of Soda Springs and registered at 5.3 on the Richter scale — strong enough to possibly damage buildings. It's been years since Southeast Idaho has experienced a quake of over 5.0 on the Richter scale.

The earthquakes have occurred at various distances east, southeast and northeast of Soda Springs, Caribou County's largest city. The farthest away were about 18 miles southeast and northeast of Soda Springs and the closest was about 2 miles east of the city.

The quakes have been felt as far away as Logan and Ogden in northern Utah and Basalt, Arimo, Pocatello, Chubbuck, American Falls, Fort Hall, Aberdeen, Blackfoot and Springfield in Southeast Idaho.