4.1-magnitude quake felt by hundreds shakes Montana, seismologists say

A 4.1-magnitude earthquake shook Montana, the U.S. Geological Survey reported.

The 3-mile deep quake hit northeast of Bozeman at 12:28 a.m. Monday, Jan. 30, according to the USGS.

More than 200 people from as far away as Butte and Helena reported feeling the tremor to the agency.

Felt this in Livingston for sure! Stood in an interior doorway for a few minutes after, too,” wrote one resident on Twitter.

“Yes Bozeman it was an earthquake! Not your imagination, a truck hitting your building, or the cold just making your house shudder,” read another Twitter post.

“So bloody cold. Now this. Thought someone was beating on the wall with a 2x4 or something,” another post read..

Magnitude measures the energy released at the source of the earthquake, the U.S. Geological Survey says. It replaces the old Richter scale.

Quakes between 2.5 and 5.4 magnitude are often felt but rarely cause much damage, according to Michigan Tech. Quakes below 2.5 magnitude are seldom felt by most people.

How are earthquakes triggered and how are their magnitudes measured? What to know