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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.
"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.
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.
The scale used to measure earthquakes is called the Richter scale. It measures the magnitude (strength) of an earthquake on a scale of 1 to 10.
Montana is located in the western region of the United States, bordered by Canada to the north. An earthquake in Montana is significant because it is not a region that is typically associated with frequent seismic activity.
The 5.8 magnitude earthquake in Montana was considered a moderate earthquake, with a magnitude between 5.0 and 6.0 on the Richter scale. It is capable of causing light to moderate damage to buildings and structures.
The potential consequences of a 5.8 magnitude earthquake can include damage to buildings and infrastructure, injuries to people, and disruption to daily activities. In rare cases, it can also trigger landslides or tsunamis.
Unfortunately, earthquakes cannot be predicted with 100% accuracy. However, scientists use seismometers to monitor seismic activity and provide warnings when possible. People can prepare for earthquakes by creating an emergency plan, having necessary supplies on hand, and securing potential hazards in their homes and workplaces.