Mount St. Helens that was, and that will be

EUGENE, Ore. - The office of the state geologist in Portland overlooks two colossal mountains, each of them a staple of Northwest geography.

More important than their aesthetics, however, is what lies beneath the hardened earth. Mount St. Helens and Mount Hood are both active volcanoes, according to state geologist Dr. Vicki McConnell.

McConnell visited the University of Oregon campus in February to talk with journalism students about how natural beauty can wreak devastating destruction.

She was still a student at Metropolitan State College in Denver when Mount St. Helens erupted in 1980, coating the Northwest in a thick layer of ash. Even though she wasn’t yet working in the field of volcanology, McConnell remembers the impact of the historic eruption.

"May 18, 1980, changed how we look at geological hazards," said McConnell. "We (the scientific community) have to help people understand that there are active volcanoes in their backyard and they’re not just for skiing on." 

The active volcanoes in the Cascade Range make up one of the most dangerous geologic risks in the Northwest, said McConnell. Mount Rainier, an active volcano located 54 miles southeast of Seattle, is the most dangerous volcano in the Cascade Range at the moment, according to McConnell.

Towering at 14,411 feet, Rainier is the highest peak in the Cascade Range . If and when it erupts, the volcano would produce enormous lahars, or volcanic debris flows, that could flood the region surrounding the volcano, including downtown Seattle, McConnell said. 

While no eruption is imminent, McConnell does predict that the volcano will erupt again.

In order to prepare for the eruption of volcanoes in the Cascade Range, McConnell said that response plans have been implemented to make sure people are aware of the dangers.

“A volcano may go into an eruptive state tomorrow,” said McConnell. “The question is are we ready?”

According to McConnell, if there are significant changes in the data gathered from monitoring a volcano that indicate it might erupt, the first step is to release information to the public through the media. Geologists would also work with the government to execute danger zones around the volcano to keep civilians away from the danger.

The second step in the plan is to form incident response teams, including land managers such as the Forest Service. These teams would work with scientists to determine what to do next in the hazard zone. The response teams rely heavily on communication between agencies involved, including scientists, the government, the media and the public.

“We scientists say that something is going to happen and we hope that people will trust us,” said McConnell.
 

The Cascade Range volcanoes pose an enormous threat, but according to McConnell, they are just one of the geological threats in the Pacific Northwest. The most dangerous geological hazard would come in the form of an earthquake along the Cascade subduction zone, said McConnell. In Oregon, such a disaster would impact lands and people from the coast into the Portland area, causing property loss, structural damages and destruction. The earthquake would also cause a massive tsunami, which would likely destroy the Oregon coast as we know it today. 

According to McConnell, the last earthquake to shake the region and create a tsunami occurred 300 years ago. These occurrences usually happen every 500 years, which means another event might not be as far away as we’d like to believe. McConnell said that response plans are in place to prepare for an earthquake if one should occur. 

While the volcanoes and potential earthquakes in the Pacific Northwest create a great geological threat, McConnell points to landslides as the most frequent geological hazard in the area. McConnell and her team work to identify potential hazards in order to act before disaster strikes.

“We don’t predict landslides,” said McConnell. “What we do is we identify where there is a potential hazard.”

This theory was put to the test in early December 2007 when severe winter storms flooded the small Oregon town of Woodson. Heavy rains caused debris flows to flow down the hill behind the town, eventually blocking the drainage under a railroad trestle-fill embankment. Due to this blockage, a small lake was formed behind the embankment. The landowner noticed this potential hazard and contacted the Oregon Department of Forestry, which quickly evacuated the town. According to McConnell, the temporary lake exploded into the town within an hour of evacuation, causing property loss and damage but sparing all human life.

The Woodson incident, according to McConnell, is an example of people working together to respond to natural disasters, which is the only way to save lives.

“What we all have to work on is being able to get out of our own boxes and communicate with each other,” said McConnell. “Our data doesn’t mean anything if people can’t use it.”

THE IMAGES OF MAY 18, 1980

Aerial view of the growing and changing dome in the volcano

Clickable map of area volcanoes