CORVALLIS - If Mount St. Helens caused many tragic deaths when it exploded 25 years ago, it has also saved lives - possibly thousands of them - as the lessons learned and the studies spawned by this catastrophic event set the stage for a new generation of scientific research into the world of volcanoes.
Geologists at Oregon State University say that the May, 1980, eruption of Mount St. Helens gave researchers an unprecedented opportunity to see and monitor volcanic forces in action, obtain data and develop new avenues of research on volcanism.
Those efforts are still picking up speed, they say, and millions of dollars of promising studies are under way at OSU that are trying to trace volcanic action to its geological foundations deep in the Earth.
"Being able to actually see and monitor the ground deformations and 1980 eruption of Mount St. Helens really opened some eyes in our research community," said Frank Tepley, an assistant professor of Oceanic and Atmospheric Sciences at OSU. "We learned a tremendous amount from that event and used it to help understand what we see elsewhere in the geologic record. We're now in a position where we can make pretty rapid progress in understanding volcanism at a very basic level."
Although the Pacific Northwest landscape is dominated by towering volcanoes, the science of plate tectonics is well-established, and monitors can record every hiccup of active volcanoes, there is still much that scientists don't understand about these awesome geologic forces.
"In general terms, we can tell you the environments where volcanoes occur, why they are there, where the heat comes from, and how eruptions occur in a crude sense," said Adam Kent, an assistant professor of geosciences at OSU, and one of a group of experts working in volcanology and petrology.
But the list of what the scientists still don't know is just as long - where the actual material comes from that becomes magma, what pathways it takes to move to the surface of the of the Earth, the time scale of these processes, what controls the magma's ascent and - most importantly - when and why a major eruption will take place.
"The biggest difference right now is we can ask much better questions about the fundamental forces of volcanism," said Roger Nielsen, chair of the OSU Department of Geosciences "We're in an era of analytical microchemistry, which will help tell us about the larger forces really at work. And we're tackling difficult issues, such as what might happen in a few years, not just tomorrow or next week."
In collaboration with experts at the U.S. Geological Survey, Portland State University, the University of Oregon, and Hewlett Packard, a whole range of new technologies have been obtained and studies are under way. They include:
- A new $1 million Electron Microprobe Laboratory at OSU is providing detailed and improved analysis of minerals and glass, helping researchers to understand the exact composition of volcanic materials and where they came from.
- An ICP mass spectrometry facility, including equipment for laser ablation microchemistry studies, can reveal the isotopic and trace element characteristics of materials.
- A number of new studies of volcanic rocks that apply this new technology, and new satellite imaging techniques are now taking place in the Cascade Range.
- An NSF-funded project lead by Anita Grunder, a professor of volcanic geology at OSU, is coordinating studies of the volcanic rocks along the axis of the Cascade Range in order to understand the geochemistry and structure of the Earth that the lavas passed through.
- Another NSF-funded study involving a west-east transect of the Central Oregon Cascade Range is examining the chemistry of volatiles and trace elements, looking for the key signals about the deep causes of volcanic eruptions within Earth's mantle.
- The role of ancient water that was carried by subduction processes deep into the Earth millions of years ago is at the forefront of research, since it may hold the key to understanding the explosive nature of Cascade volcanoes and the way that water affects how the materials in the deep Earth melt.
- New clues to volcanic action are being provided by "melt inclusions," microscopic droplets of lava that have been trapped within a crystal, almost like a volcanic fossil, and can help scientists learn about conditions at the time the lava existed long before it erupted.
Despite not being able to answer questions about exactly when and where the next big volcanic event may occur - that's a little like the dicey science of earthquake prediction, researchers say - the lessons learned in recent years have already saved lives. Taken together, the information gathered will help us to understand in greater detail where the lavas come from, what they do on the way to the surface and why they behave the way they do.
"The researchers in the 1980s would be amazed at what we can do now," said Nielsen. "Much of what we learned from Mount St. Helens helped to save thousands of lives in the Philippines when Mt. Pinatubo erupted in 1991."
An OSU graduate student, Michael Rowe, is now working with the USGS at Mount St. Helens, taking "fingerprints" of volcanic ash. Through sophisticated new tests, researchers are able to determine the age of the magma the ash came from, where the magma was and how fast it had been moving.
The science is getting better in many respects and leading to constant advances, the researchers say. But they are also quick to concede it has room for improvement and that volcanic hazards are still very difficult to predict.
A helicopter landed at what appeared to be a safe site in the crater of Mount St. Helens not long ago on a science mission - a volcanic area that has, in general, received more scientific study in the past 25 years than just about anywhere on Earth.
Just 36 hours after the helicopter's landing, that exact site blew up in a volcanic explosion.