Baylor Geologist Closely Watching Mount St. Helens Activity

by Judy Long

As Mount St. Helens vents steam mixed with small amounts of ash daily and watchers anticipate more activity, volcanologist Don Parker, Baylor University professor of geology, expects the activity to continue for awhile.
"This is a continuation of what began 24 years ago, when the volcano erupted on May 18, 1980. They are not expecting an eruption on the scale of the 1980 one. This one will be smaller, but of course, we don't know how big it will be. So far, we've only seen steam explosions. At some point, they think magma will burst through," he said.
Parker has visited the most active volcano in the contiguous 48 states several times and enjoys a professional relationship with some of the geologists who make Mount St. Helens their primary research focus. He is researching similar, but older domes in West Texas and Colorado.
He said one concern to consider with an erupting volcano is the ash and steam it sends tens of thousands of feet into the air. "The FAA monitors it because they're concerned about jets sucking ash into their engines. When the Redoubt Volcano in Alaska was erupting in 1989 and 1990, jets that flew through the steam had to make emergency landings because their engines were damaged from the particles," he said.
Parker explained ash is fragmented magma. "If you look at it under a microscope, it's made up of sharp pieces, so if someone breathes it, the points stick in their lungs and do all kinds of damage.
"The Mount St. Helens magma is a high silica type, which is particularly sticky--it has a high viscosity. The high viscosity makes it difficult for volatiles like water to escape peacefully; hence, the violent eruptions." he said.
There are no active volcanoes in Texas, Parker said. "But we do have old ones. West Texas was very active 40 to 17 million years ago, and Big Bend has some rhyolite domes." Rhyolite is rock formed from molten lava.
The hour-long blast at Mount St. Helens Tuesday morning was the largest one so far in the activity which began Friday, but some scientists believe there is about an 80 percent chance that potentially explosive fresh magma will reach the surface.
For more information, contact Parker at Don_Parker@baylor.edu or by phone at (254) 710-2192.