SKAMANIA COUNTY, Wash. — For thousands and thousands of years, the Pacific Northwest has had a history of active volcanism. And on May 18, 1980, Mount St. Helens violently erupted. Many in central and eastern Washington remember the day vividly.
And while that's the most recent volcano to erupt in our lifetime, several of the tall mountain peaks such as Mt. Rainier, Glacier Peak, Mt. Hood, and Mt. Shasta are still active volcanoes. And all these volcanoes up and down the Cascades are being closely monitored by the United States Geological Survey (USGS).
"They're not these quiet, stately monoliths just sitting there. There's lots of chatter and talking going on and we're monitoring all of that. And we're trying to understand what is typical background. Because there what we want to be able to understand and pick up early is what abnormal, what's unusual in that monitoring," says Jon Major, the Scientist in change at the USGS Cascades Volcano Observatory.
Learning from Mount St. Helens
While there are emergency plans in place for future eruptions, the volcano's history and its behavior is also being uncovered. For example, the massive landslide that was documented at Mount St. Helens was thought to be unique and unusual. But after the event, scientists learned that landslides and changes to the local geography has happened several times for many active volcanoes in the region.
"The landslide we saw at Mount St. Helens, that's happened at Mt. Rainier, that's happened at Mt. Hood, that's happened at Mt. Shasta. So all the processes we saw that morning have happened at all our other volcanoes."
But the "Lateral Blast" of the 1980 eruption remains a defining feature of Mount. St. Helens' most recent eruption.
Mt. Mazama's catastrophic eruption
And while that eruption left a layer of ash across the Inland Northwest, this was nothing compared to one of the most catastrophic volcanic eruptions the Pacific Northwest has ever seen.
"All we have to do is go back roughly 7,000 years to Crater Lake."
"Mt. Mazama is known for a massive catastrophic eruption."
An eruption so large that the mountain peak itself collapsed after the magma and gasses were released - leaving the caldera that's now Crater Lake behind. And 7700 years later, a huge layer of ash was discovered in Spokane County, where Andy Buddington was able to study this incredible observation.
"Now we have 71 cm of ash documented out at Saltese. The thickness of the ash can become overthickened, but nonetheless, we were able to correlate it to Mt. Mazama," Buddington said.
Shaped by volcanic eruptions
Pacific Northwest volcanoes will continue to be a part of our past and future. But as the mountains rest, there is a beauty left behind.
"The Palouse region is underlain by a special type of soil known as loess soil. And with these periodic eruptions of ashy material which is enriched in many different chemical elements, help kind of fertilize the soli, reinvigorate the soil with essential nutrients."
The USGS remains up to date with their computer modeling regarding what would happen if a 1980s magnitude eruption would happen today. The site is updated daily. You can see what it looks like here on the USGS website.
WATCH MORE: 42nd anniversary of Mount St. Helens eruption