A remote patch of south-central Utah shook awake Sunday morning as a swarm of more than 30 small earthquakes rolled through the landscape south of Fillmore. The largest of the bunch registered magnitude 3.6 at about 8:43 a.m. local time, capping a sequence that kicked off before dawn with a roughly magnitude 3.2 quake near Kanosh and continued with dozens of smaller jolts through the morning. Officials said the shaking hit a sparsely populated area, and there were no immediate reports of damage or injuries.
Largest shock and where it hit
The biggest quake in the swarm was logged as a magnitude 3.6 with an epicenter about 8 kilometers south-southwest of Kanosh, recorded at 14:43 UTC (8:43 a.m. MDT), according to the U.S. Geological Survey. The event is listed as shallow and has been reviewed by a seismologist. The USGS feed serves as the main public record for time-stamped quake data and crowdsourced “felt” reports.
Seismologists describe the sequence
Scientists with the University of Utah Seismograph Stations told local media the swarm began around 5:45 a.m. with a magnitude 3.2 event and that 32 earthquakes were recorded in the same general area over the next several hours, as reported by KJZZ. The outlet also notes that UUSS data show 225 earthquakes of magnitude 2.0 or larger within 15 miles of this cluster since the early 1980s. Researchers say swarms like this are often self-contained episodes and do not necessarily signal that a larger quake is on the way.
Why many of these quakes go unnoticed
Most earthquakes are minor ones: events of about magnitude 2.5 or lower are typically picked up by instruments but not felt by people, according to Michigan Technological University. The U.S. Geological Survey listing for the 3.6 quake shows only a handful of public “felt” reports, underscoring that relatively few residents in the remote Kanosh–Fillmore area reported noticeable shaking. Seismologists plan to keep an eye on the swarm for additional aftershocks and will update public feeds if activity picks up.
How to report shaking and stay prepared
If you did feel any of the shaking, the state encourages residents to submit a report and brush up on safety tips on the Utah Earthquake Program website, according to the Utah Earthquake Program. Officials also recommend checking older masonry for cracks, securing loose items that could fall, and keeping a family emergency plan current while seismologists watch for any notable changes in activity. This story will be updated if state or university experts release new findings or if officials report any damage.
