38 years later: What’s changed since Mount St. Helens erupted?

Posted at 1:01 PM, May 18, 2018
and last updated 2018-05-18 13:01:00-04

SEATTLE – In the early spring of 1980, Mount St. Helens had a single seismograph monitoring earthquakes on the mountain.

After numerous quakes were measured, more equipment was installed. But by May 18, 1980, only 10 seismographs were in place to monitor the most destructive volcanic eruption in US history; fewer than are on the mountain today.

"There's a dozen to 15 seismographs on or around Mount St. Helens right now,"  professor emeritus with the Department of Earth and Space Sciences at the University of Washington Steve Malone tells KCPQ.

According to Malone, it's not just the number of seismographs that has improved earthquake and volcanic activity monitoring on one of the Pacific Northwest's most iconic mountains. It's technology that has improved 100 times over.

Before, much of the data collection was done on tapes and gathered by hand. Now, computers do most of the work, Malone said.

"These days our computers are really smart," Malone said. "They monitor the mountain 24-7 in real-time and page us or phone us if something is out of the ordinary."

Technology other than seismographs have also sprung up in the three decades since the Mount St. Helens eruption. GPS, satellite imagery and gas registration techniques all better monitor St. Helens and other volcanoes in the Cascades, Wes Phelen, a USGS seismologist, said.

"All of this raw data put together gives us clues as to what is going on in the volcano," Phelen says.

Institutional knowledge of Pacific Northwest volcanoes and how they work has also improved, Phelen and Malone said. Prior to the 1980 eruption, most live information on volcanoes came from seismograph stations on Hawaii. But Hawaiian volcanoes operate differently than the Cascades. Years of studying Mount St. Helens and the smaller eruptions that have come in the past three decades have been invaluable, Malone said.

"It's been a laboratory that we develop new equipment," Malone said.

With increased monitoring comes more advanced warning. While it's still impossible to predict exactly when an eruption will occur, the scope and severity of a coming blast is easily monitored, Malone said. And things like evacuation area and routes can be better planned.