Last month, Columbian Editor Craig Brown used the anniversary of our nation’s most memorable geological event to point out how the news industry has changed.
“Should a major eruption occur, we’d press all of our staff into service,” Brown wrote, reflecting on the anniversary of the 1980 Mount St. Helens eruption. “We’d direct our coverage online first, starting with our social media channels. Top priority would go to official messages urging the public to take action, followed by ‘current status’ stories, followed by reaction stories.”
Fortunately, a major eruption is unlikely. And, as the U.S. Geological Survey reports, an explosive event is nigh impossible: “Neither a large debris avalanche nor a major lateral blast like those of May 18, 1980, is likely now that a deep crater has formed.”
But that hasn’t prevented recent breathless headlines such as “Washington volcano recharging 44 years after eruption” from appearing in media around the globe. And it has not mitigated our fascination with the United States’ most famous volcano.
Yes, Mount St. Helens is rumbling again. The USGS reports that more than 350 earthquakes have been recorded in the area since the beginning of February. That includes a high of 38 temblors during the first week of June.
All of this is part of a process known as “recharging.”
“Magma slowly rises through the lower crust and accumulates in a reservoir about 2.5 to 6 miles below sea level,” according to officials at the Cascades Volcano Observatory in Vancouver. “Recharge events can occur when magma enters this upper reservoir and increases stresses that lead to earthquakes.”
A similar process occurred from October 2004 to January 2008, when a new lava dome built up inside the crater created by the 1980 explosion. A series of steam eruptions were visible during the period, with the largest plume reaching a height of 38,000 feet.
“High rates of seismicity, interpreted as recharge, have been observed in the past at Mount St. Helens and at other volcanoes and can continue for many years without an eruption,” officials said this month. “No significant changes have been observed in other monitoring parameters and there is no change in alert levels at this time. Mount St. Helens remains at normal, background levels of activity.”
But normal for Mount St. Helens is extraordinary for most mountains. Although the Cascades are formed by a series of volcanoes as part of the Pacific Ring of Fire, most of them have been dormant for centuries. (Interesting factoid: The last major volcanic eruption in Canada was 2,500 years ago in the Mount Meager area, about 100 miles north of present-day Vancouver, British Columbia).
That frequent activity from an 8,363-foot mountain in Skamania County (it was 9,677 feet before May 18, 1980) has attracted volcanologists from throughout the world over the past four decades. The USGS writes: “The relationships built with international colleagues, the advances in monitoring, and the skills accumulated have made it possible for U.S. scientists to aid with eruption responses worldwide.”
All of which contributes to continued public interest in Mount St. Helens. When the mountain rumbles, people take note and wonder whether an eruption is imminent. People who know about such things say major activity does not appear to be in the works, and that a buildup of explosive pressure cannot occur again.
But The Columbian will be ready — just in case.
