Magnitude 4.7 Earthquake Hits Near Popular NorCal National Park in Rare Seismic Event

Initially registered as a magnitude 5.0, Sunday’s earthquake in Lassen National Park was later downgraded upon further analysis.

Home to the largest plug dome volcano in the world, Lassen National Park attracts hundreds of thousands of visitors annually. Those visiting the mountain park yesterday afternoon were treated to a rare break from beneath when a 4.7-magnitude earthquake rattled the area.

According to the United States Geological Survey (USGS), Sunday’s afternoon tremor created shockwaves felt as far away as Sacramento — about 150 miles away from the quake’s epicenter. As of Monday morning, four aftershocks registering between 2.1 and 2.5 magnitude in strength have been recorded. 

Unlike the earthquakes familiar to Bay Area residents, Lassen National Park’s ground-shaking history is primarily due to the area’s volcanic activity and not tectonic movement. More than 40 volcanoes varying in size and formation style dot the park, producing its famous hydrothermal displays, sloping vistas, and rich foliage. The last major volcanic eruption at Lassen National Park is poorly documented, but observations suggest it occurred well over a century ago between 1914 and 1917; geologists agree the eruption was sizeable and devastating, sending plumes of toxic, suffocating ash hundreds of miles away and devastating agricultural harvests in the Cascades.

Thankfully, such an eruption only occurs about once every 10,000 years in the park, so it’s unlikely Sunday’s in-park earthquake — which, with a 4.7 magnitude rating, makes it among the strongest to strike the area in over three years — is hinting at an impending eruption. It just served as a reminder that the floor is, indeed, lava (or rather has molten rock running beneath it).

Matt Charnock