“In September, the US Geological Survey Cascades Volcano Observatory (CVO) and Pacific Northwest Seismic Network (PNSN) located six earthquakes at Mount Adams, ranging from magnitudes 0.9 to 2.0. Typically, earthquakes at this volcano are located at a rate of about 1 earthquake every 2-3 years. With just one seismic station near the volcano, monitoring capabilities are currently limited. CVO and PNSN plan to install temporary seismic stations in the Mount Adams area, which will allow detection of smaller earthquakes and better estimates of size, location, and depth, information necessary to assess the significance of the activity. Currently, there is no indication that the level of earthquake activity is cause for concern, and the alert level and color code for Mount Adams remain at GREEN / NORMAL. CVO and the PNSN will continue to monitor earthquake activity and release further updates as the situation warrants.”

“Six locatable earthquakes (magnitude 0.9–2.0) were detected in September on seismic station ASR2, a PNSN-operated station located about 7 miles (11 km) southwest of the summit of Mount Adams, as well as other stations much farther away from the volcano. This represents the most earthquakes located at Mount Adams in a month since monitoring began in 1982. No earthquakes were felt at the surface. The locations and depths are not well constrained due to the sparse Mount Adams seismic network, and smaller earthquakes have occurred that seismologists have been unable to locate. Satellite imagery does not show any detectable ground deformation at the volcano. Mount Adams does not have a dedicated volcanic gas sampling program,” says a USGS update.