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Volcanoes In Our Backyard

OPB | Jan. 24, 2008 12:30 p.m.

In October 2004, almost 25 years after Mount Saint Helens blew 1,300 feet off its top, the volcano again erupted. It was a small eruption compared to the cataclysmic blow of 1980, but it made clear that the mountain was coming back to life. But Mount Saint Helens isn’t the only volcano in the Northwest showing signs of life.

First Broadcast: 2008

A New Awakening

Mount Saint Helens erupted with just two months’ warning in 1980. Had the technology we have today been available then, scientists may have been able to detect the swelling of the earth and accumulation of lava prior to the explosion. That technology is now being used to measure the swelling of the ground in the newly awakened volcanic zone near Bend. Rising at the rate of about one-and-a-half inches a year, some scientists think this could portend more volcanic activity. Are the Cascades entering a new era of eruptions?

Resources

Downtown Mount Saint Helens?
How would Portland look in the crater of Mount Saint Helens?
Mount Saint Helens VolcanoCam
Live view (when the weather cooperates) of the mountain from the Johnston Ridge Observatory — via USFS.
Sugar Bowl DomeCam
This USGS observational camera, located 1.4 miles from the vent, captures Mount Saint Helen’s changing lava dome once daily. Scientists stitch these images into stunning time-delayed video of geological change.
USGS Photography on Saint Helens
Land and aerial photography of the mountain, its lava dome, and USGS scientists at work in the field.
GlacierCaves.com
Information about the International Glaciospeliological Society (IGS) and their work around volcanoes worldwide.

Downtown Mount Saint Helens?

Downtown Portland would fit inside the crater of Saint Helens

This photoillustration juxtaposes two prominent features of the Pacific Northwest: the crater of Mount Saint Helens, and the downtown Portland waterfront skyline.

How we scaled out the “Portland in the Crater” image:

This image is an an approximation of how Portland’s downtown area would appear if dropped into the crater of Mount Saint Helens. Here’s how we determined scale. Portland’s tallest tower, the tall, straight tower in the center of the photo is the Wells Fargo building, at 544 feet in height. The approximate width of this city in our photograph is one mile. The crater floor where we placed the city is approximately 1 mile in width as well, though it’s partially obscured in this image. The flat part of the crater in front of the domes sits at an elevation of approximately 6300 feet. The 1980’s era dome, the dark mass immediately behind the skyline, rises about 900 feet above the floor. That would be over 400 feet above the Wells Fargo tower. The new dome as it looked in September ‘05 is the gray mass tucked between the crater rim and the 1980’s dome.

Here’s where things get tricky… The new dome emerged from beneath a glacier, so the elevation of the crater floor here is hard to determine. The part of the glacier we see sits between 6800 and 7200 feet in elevation. The new dome rises up, and crumbles, rises and crumbles, so it’s actual height changes daily. We don’t have an exact elevation for the new dome in this image but in July ‘05- two months before this photo- the dome reached 7700 feet That’s almost a thousand feet higher than the Wells Fargo building! To demonstrate how quickly things change — in November ‘05 the dome was back to only 7000’, and in January ‘06 it rebuilt to over 7300’ — that’s a loss of 7000 feet and a gain of 300 feet in a period of just 6 months.

Want another perspective? The tallest point in the West Hills rises about a thousand feet above Portland’s downtown streets. That’s just a bit taller than the new dome at it’s highest point. Just imagine the West Hills taking shape in one year!

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Additional Support Provided By:

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