5.8 Magnitude earthquake hits Montana

[Evo]

A magnitude 5.8 earthquake that rocked western Montana early Thursday morning was the largest quake to hit the area in the past 20 year, the U.S. Geological Survey said.

http://www.foxnews.com/us/2017/07/06/montana-earthquake-5-8-magnitude-earthquake-felt-in-region.html

 

[fresh_42]

Would be interesting to know, whether 200 miles can be considered save enough.

 

[Astronuc]

It certainly made national news this morning, with some wondering about the 'supervolcano' under Yellowstone, which is about 230 miles from the mag 5.8 quake's epicenter.

https://www.yahoo.com/news/natural-disaster-5-8-magnitude-150301642.html

"The location and focal mechanism solution of this earthquake are consistent with right-lateral faulting in association with faults of the Lewis and Clark line, a prominent zone of strike-slip, dip slip and oblique slip faulting trending east-southeast from northern Idaho to east of Helena, Montana, southeast of this earthquake," said the USGS.

https://earthquake.usgs.gov/earthquakes/eventpage/us10009757#executive

The July 6, 2017 M 5.8 earthquake southeast of Lincoln in western Montana occurred as the result of shallow strike slip faulting along either a right-lateral, near vertical fault trending east-southeast, or on a left-lateral vertical fault striking north-northeast. The location and focal mechanism solution of this earthquake are consistent with right-lateral faulting in association with faults of the Lewis and Clark line, a prominent zone of strike-slip, dip slip and oblique slip faulting trending east-southeast from northern Idaho to east of Helena, Montana, southeast of this earthquake. The Lewis and Clark line is a broad zone of faulting about 400 km in length, and up to 80 km wide (wider to the east). Faults within this zone, primarily of Middle Proterozoic to Holocene in age, can be traced as much as 250 km along strike, and typically change in strike from east (near Idaho) to southeast (near Helena). In the region of the July 6th earthquake, prominent faults include the St Mary’s-Helena Valley fault, and the Bald Butte fault, both right-lateral structures. More detailed field studies will be required to identify the causative fault responsible for this earthquake.

 

[1oldman2]

A nice string of aftershocks lately, I'm about 160 km's from Lincoln and the 5.8 event nearly tipped over the Fridge and Flat screen but the kids loved it and are disappointed things are settling down. http://earthquaketrack.com/r/western-montana/recent (Lincoln is also noted for being the former home of the "Uni-bomber" prior to his law enforcement issues.)

 

[Sue Rich]

In the early '80s, an earthquake hit Oregon (I believe it destroyed a school) and it was felt with a strong force in Montana. I remember it clearly. Our entire house rocked. We were in Kalispell (northwest), Montana.