Rise of plate tectonics led UO into volcanology research

Image taken from Newberry’s Paulina Peak shows Paulina and East lakes

As plate tectonics emerged as a theory in the 1960s, scientists began unraveling mysterious geological processes tied to mountain building, volcanic eruptions and earthquakes. At the University of Oregon, campus leaders realized a natural laboratory was at their doorstep.

Skinner Butte, formed from a basaltic intrusion of ancient lava, overlooks Eugene. The nearby Cascade and Coast mountain ranges contain volcanoes, including the Three Sisters, which are visible from the city. And a little more east, near Bend, is the Newberry Caldera. Regional earthquakes are not strangers. Oregon is on the Ring of Fire, a horseshoe-shaped belt outlining most of the Pacific Ocean basin and home to earthquakes and volcanoes.

Birth of the program

In 1965, leaders in the UO’s geology department, now the Department of Earth Sciences, and UO President Arthur Fleming formed the Center for Volcanology and recruited Alexander “Mac” McBirney, a rising star at the Scripps Institute of Oceanography in San Diego, to lead it. He brought two Scripps colleagues with him, geochemist Gordon Goles and experimental petrologist Dan Weill, who studied the composition, texture and structure of rocks, to build an interdisciplinary foundation.

“The UO already had founded the Institute of Molecular Biology in 1959, but the UO wanted to do something more to help make it distinctive,” said Dana Johnston, professor emeritus, who joined the volcanology group in 1986. “As part of that deal, they gave Mac a building, the Volcanology Building, which had previously been the university’s first infirmary. Above many of the office doors you can still see some bells, which you used to ring for the night nurse.”

McBirney already was doing cutting-edge volcanology research in the Galapagos Islands and along plate boundaries on the floor of the Pacific Ocean. That continued, with him taking UO students into the field.

“McBirney early on was influential in thinking about subduction zones and their relationship to plate tectonics,” said Josef Dufek, the current director of what is now known as the Oregon Center for Volcanology. “This fell into the idea that volcanoes were tied to the regime of plate tectonics, which at the time was revolutionary thinking. Before the advances in sonar and magnetic field mapping following World War II, we didn’t know about plate tectonics. McBirney brought ideas from geophysics, geochemistry and petrology to the table.”

McBirney also was forward-looking. As NASA was expanding its Apollo program, McBirney and colleagues jumped at funding opportunities and obtained pieces of moon rock for study at the UO. Using the lunar samples, McBirney’s group was able to produce comparable rocks.

“We took the reported chemical composition of the analyzed samples, mixed the various components according to those specifications, then melted them,” McBirney told the Eugene Register-Guard for a story published in May 1970. “For all practical purposes, it’s the same rock. We can even crystalize the same minerals from it.”

By the time McBirney retired in 1989, numerous landmark studies on various aspects of volcanology had been published by his group. Early in his tenure, he began taking students into the Cascades, where little volcanology research had been conducted. By time he retired, he had overseen the awarding of 12 doctoral degrees.

Students at June 2019 field camp work around pit at Newberry volcano
Undergraduate students from both the University of Oregon and other institutions gather around a pit dug on the eastern side of Newberry volcano during a Department of Earth Sciences summer field camp. In the hole, a student describes her observations of material from an eruption 1,300 years ago. Students around the pit are taking notes or drawing a cross section of volcanic materials present in the soil. The sampling and subsequent analyses in UO labs helps researchers understand how the eruption started, progressed and ended. (Photo by Thomas Giachetti)

McBirney’s research, including groundbreaking discoveries in the layers of minerals and igneous rocks in the Skaergaard intrusion in Greenland, served to write the book on the composition of lava and volcanic rocks. His textbook “Igneous Petrology,” now in a third edition, is still widely used and considered to be an important resource on igneous rocks, which form from cooling and solidification of magma or lava.

Sample image
Joe Dufek
"Before the advances in sonar and magnetic field mapping following World War II, we didn’t know about plate tectonics. McBirney brought ideas from geophysics, geochemistry and petrology to the table.”
Joe Dufek, director, Oregon Center for Volcanology

Expansion and growing recognition

The approach established by McBirney continued with new team members.

Among them was Katharine Cashman, who joined the UO in 1991 and now leads a large volcanology group at the University of Bristol in the United Kingdom. While at the UO she won the American Geophysical Union’s prestigious Bowen Award, headed the department for three years and served as president of the AGU’s volcanology, geochemistry and petrology section.

Dana Johnston and Paul Wallace led the Department of Earth Sciences before and after Cashman’s term and helped establish the vision and infrastructure for the present volcanology center.

Johnston, who later served as divisional dean of natural sciences in the College of Arts and Sciences, established a lab for high-pressure experimental petrology. Wallace, now a professor in the Department of Earth Sciences, is an expert on volatile cycling and the role of volatiles, like water vapor and carbon dioxide, in the behavior of volcanoes.

In 2014, campus leaders selected the UO’s volcanology program as one of five clusters of excellence targeted for growth. Two years later, Gwendolyn Lillis and Charles Lillis committed a $10 million gift, leading to new hires, including Dufek, to strengthen the program. The Lillis gift contained a $2 million challenge component that was matched in late 2019. Now fully funded, the gift has propelled faculty growth.

“News of that push for our cluster made for a lot of conversation in the discipline in general,” said Dufek, who came to the UO from Georgia Tech. “With the new hires, we have become the largest academic volcanology group in the U.S.”

The group’s 13 members hold doctorates from eight research universities, including five from the University of California, Berkeley and two from the joint Massachusettes Institute of Technology-Woods Hole Oceanographic Institution program. Also represented are the University of Chicago, University of Miami, University of Washington, University of Clermont-Ferrand in France, University of Minnesota and Stanford University.

Mysteries remain

“Some perceive geology as a static science, but that couldn’t be further from the truth,” Dufek said. “We certainly do try to decipher the story of past eruptions by studying volcanic samples. But volcanology is an interdisciplinary and dynamic field. We draw on information from high-performance computing, the development of new analytical geochemical techniques and building sensors to measure things in extreme environments. Studying volcanoes is really a good test bed for studying extreme conditions.”

While UO researchers have helped to answer a lot of questions about types and formation of volcanic rocks, eruption styles and locations of underground magma chambers, there are mysteries for today’s team and students to explore, Dufek said. One goal being pushed by the National Academies of Science, he said, is being able to forecast eruptions. A hurdle is the inability to measure regions of melt below volcanoes.

“If you are thinking about forecasting weather, you can measure various factors in three dimensions in the atmosphere,” Dufek said. “With various techniques, you can get a good idea of what conditions are, but even then it is still hard to accurately forecast what’s coming. When we look at (volcanic) melt in the subsurface, it’s always by indirect means: how seismic waves change when going through melt, how the ground deforms and what gravity tells us. This uncertainty in initial conditions makes forecasting eruptive conditions particularly difficult.”

That means there are uncertainties to explore. Mount St. Helens, for example, had a buildup of magma and exploded. Campi Flegrei near Naples, Italy, and the volcanoes at Yellowstone and the Three Sisters, however, have seen inflation but have not erupted.

“Deformation alone is not sufficient to diagnose an eruption,” Dufek said. “Many intrusions stall without erupting. It’s generally believed that about 10 times the magma stalls in the subsurface compared to what actually erupts. A lingering question is: What triggers eruptions?”

—By Jim Barlow, University Communications