5.9-magnitude Earthquake Rattles Residents in Nevada and California

Posted: July 9, 2021 10:57 am

Phantom Quake Alarms Residents Throughout West Coast

As if the searing heat was not enough to deal with this week, parts of the West Coast were treated to a 5.9 earthquake on Thursday afternoon.

Details of Tremor

The quake was reported just south of Lake Tahoe along the border of California and Nevada. To be exact, the tremor was centered smack dab in the Little Antelope Valley, approximately four miles south of Coleville in Mono County. However, the event was felt by people located hundreds of miles away.

The tremor triggered a series of approximately 30 aftershocks for at least two hours after the initial event. The first quake measured a depth of about 5 miles. According to the experts, Thursday’s big quake was the largest one in over two decades in the region.

Phantom Quake

Although the seismic event was originally reported as two separate major earthquakes, the US Geological Survey (USGS) eventually revised the report to delete one mistakenly reported tremor just south of Stockton, California. The false report was the result of an automatic systems error. It is not uncommon for these earthquake reporting systems to report these secondary waves as separate quakes, coining the term “phantom quake.”

Widespread Movement

Despite the deletion of the phantom quake, the initial tremor was indeed very real. The shaking was reported in both California and Nevada. According to the USGS, there were over 20,000 reports by 6 pm.

The shaking of the earth triggered rockslides, necessitating the closure of about 40 miles of US 395. As one of the major highways through the northern Sierra Nevadas, this closure led to widespread traffic delays. While a few vehicles were struck by the falling rocks, there were no reports of injuries. The road eventually reopened with crews remaining nearby in the event of aftershocks.

Officials caution that reports of injuries from the day of the activity are preliminary. Since so much of the worst shaking happened in rural areas, the true damage may not be known for a few days.

Quake Sparks Fear

Californians are used to living in fear of earthquakes, always wondering if this one is going to be “the big one.” A quake of this magnitude certainly did not do much to calm these fears. Just north of the epicenter, officials in Reno, Nevada, made the decision to evacuate City Hall out of an abundance of caution.

Active Fault Line

Thursday’s tremor happened along the eastern edge of the Sierra Nevada fault line. This line stretches along the eastern edge of the Sierra Nevada mountain range in California. The fault line runs about 370 miles in length from the top of the Garlock Fault up to the Cascade Mountains. Meteorologists believe that Thursday’s seismic event was consistent with the normal activity along this fault line