Have You Felt Them? The Surge Of Small Earthquakes Near Hanford

The Pacific Northwest Seismic Network (PNSN) has recorded an uptick in seismic activity, with over 100 small earthquakes shaking the area between Saturday and Wednesday. The majority of these tremors were concentrated on the western edge of the McGee Ranch area, part of the Hanford Reach National Monument.

Natural Occurrence

Despite its proximity to one of the nation’s most well-known nuclear sites, experts are reassuring the public that these quakes are a natural occurrence and not linked to the site's radioactive waste. Renate Hartog of the PNSN clarified that the activity is what's known as a “seismic swarm,” which refers to clusters of earthquakes without a clear mainshock. Such swarms are quite common in Washington and Oregon. 

Seismic Swarms

Seismic swarms, while often unsettling, are typically harmless, occurring when there’s a buildup of tectonic stress along fault lines or volcanic regions. This recent series of quakes serves as a reminder of the Pacific Northwest's geological dynamism. Though there are many earthquakes, most have not even been felt by humans due to their remote location and the size of the quakes themselves, with most being a 2.0 magnitude and the largest reaching 2.9 magnitude. It's believed these quakes are occurring about five miles down in the crust.

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PNSN

The PNSN, which is responsible for monitoring and analyzing seismic activity in the region, operates through the University of Washington and the University of Oregon. Supported by both federal and state agencies, the network plays a crucial role in tracking and understanding earthquake patterns in the region.