Six earthquakes were recorded at Mount Adams in September

MOUNT ADAMS, Wash. – Six earthquakes were recorded at Mount Adams in September, the most since monitoring began in 1982, according to the U.S. Geological Survey's Cascades Volcano Observatory.

The agency and the Pacific Northwest Seismic Network recorded six earthquakes at its seismic station, located about 7 miles southwest of the volcano's summit, as well as at other stations further from the volcano. These earthquakes ranged in magnitude from 0.9 to 2.0.

According to the USGS, earthquakes at Mount Adams typically occur every two to three years.

No earthquakes were felt on the surface, the agency said, and there were other smaller earthquakes that were not located. Satellite images have also shown no ground deformation at Mount Adams.

“At this time, there is no indication that the level of earthquake activity is of concern, and the alert level and color code for Mount Adams remain at GREEN/NORMAL,” USGS assured.

Experts will continue to monitor earthquake activity.

Mount Adams' seismic network is sparse, with only one station near the volcano, but the Cascades Volcano Observatory and the Pacific Northwest Seismic Network plan to establish additional temporary stations in the area that will detect smaller earthquakes and provide stronger data estimates their size, location and depth. These stations will be located south and southwest of the volcano.

The second tallest volcano in Washington is classified as a “high threat” volcano by the USGS. If it erupts, residents will encounter lahars, which are flows of muddy rock, ash and ice flowing downstream and causing landslides, the agency said.

The southern Washington volcano is located about 50 miles west-southwest of Yakima and 30 miles north of the White Salmon-Hood River area in Washington and Oregon. Mount Adams is part of the Mount Adams-King Mountain volcanic field, which contains more than 120 smaller volcanoes in portions of Skamania, Lewis, Klickitat and Yakima counties and the western part of the Yakama Nation.