Mount Adams in Southwest Washington experienced an unusual increase in seismic activity during September, with six low-intensity earthquakes detected, the highest monthly count since monitoring began in 1982. Experts assure there is no immediate eruption threat, as the volcano has been dormant for thousands of years. Current monitoring efforts are limited, but plans are in place to expand these capabilities in the future.
In September, the United States Geological Survey’s Cascades Volcano Observatory reported a series of six low-intensity earthquakes occurring beneath Mount Adams in Southwest Washington. This surge in seismic activity marks the highest monthly count since monitoring began in 1982, yet officials assure that there remains no imminent threat of eruption. The volcano, which rises to 12,276 feet, has been dormant since its last eruption, estimated to have occurred between 3,800 and 7,600 years ago. The detected earthquakes registered magnitudes between 0.9 and 2.0, classified as ‘extremely small’ by geologist Holly Weiss-Racine, who noted that individuals in the vicinity would not have felt them. Typically, Mount Adams experiences seismic activity at a rate of about once every two to three years. Weiss-Racine expressed interest in the recent increase, yet emphasized that it does not indicate a significant change in volcanic behavior. Weiss-Racine further elucidated that several indicators might suggest a volcano’s awakening or unrest, such as increased seismicity, ground deformation, and heightened gas emissions. She stated, “Right now, we’re not seeing any of those things. We’re just seeing these six earthquakes.” Comparatively, other local volcanoes exhibit varying levels of background activity; for instance, Mount Rainier may experience several minor tremors each day. Should Mount Adams erupt, geologic data suggest a different phenomenon than the catastrophic 1980 eruption at Mount St. Helens, which resulted in substantial ash clouds and loss of life. Weiss-Racine characterized Mount Adams as a less explosive volcano, primarily producing thick, viscous lava flows due to its geological makeup, distinguishing it as the largest volcano by volume in the Cascade Range. One significant hazard posed by a potential eruption is the risk of lahars—volcanic mudflows that can originate from even minor eruptions. This mixture of melted glacial ice and volcanic debris poses a threat to downstream areas, particularly Trout Lake in Klickitat County. The most recent earthquakes appeared to originate from the central region of Mount Adams, although precise determination of their depth and location is hampered by limited monitoring capability, with only one station positioned seven miles southwest of the summit. In response, the Cascades Volcano Observatory has deployed a temporary seismic station and plans to install two additional stations. Congress authorized a novel volcano early warning and monitoring system in 2019. Currently, the U.S. Geological Survey is working to establish four additional monitoring sites at Mount Adams, contingent upon receiving permits from the U.S. Forest Service for the necessary equipment installation, which is anticipated to include more advanced technology than the existing single monitoring station. The Forest Service is expected to complete its approvals within the upcoming month; however, due to the expected weather deterioration as winter approaches, permanent stations might not be operational until the following year.
Mount Adams, a dormant volcano located in Southwest Washington, is part of the Cascade Range and is monitored for seismic activity by the U.S. Geological Survey’s Cascades Volcano Observatory. Since 1982, monitoring efforts have aimed to detect any signs of volcanic unrest, including changes in earthquake frequency, ground movement, or gas emissions. Although seismically active, volcanic eruptions have occurred infrequently, with the last significant eruption occurring several millennia ago. Standard monitoring relies on instrumentation strategically placed around the volcano to assess and mitigate potential hazards.
In conclusion, the recent seismic activity beneath Mount Adams has raised interest among researchers and officials, yet it does not currently indicate an imminent eruption threat. Continued monitoring and data collection will be essential to ensure public safety, particularly regarding potential hazards such as lahars. Enhanced monitoring systems are in development to better understand volcanic behavior and respond effectively to any future threats.
Original Source: www.seattletimes.com
