Dangerous volcanoes in the U.S. are getting only scant monitoring
Seth Moran is worried about Mount Hood.
In the 1780s, the volcano rumbled to life with such force that it sent high-speed avalanches of hot rock, gas and ash down its slopes. Those flows quickly melted the snow and ice and mixed with the meltwater to create violent slurries as thick as concrete that traveled huge distances. They destroyed everything in their path.
Today, the volcano, a prominent backdrop against Portland, Oregon, is eerily silent. But it won’t stay that way.
Mount Hood remains an active volcano, meaning that it will erupt again. And when it does, it could unleash mudflows not unlike those from Colombia’s Nevado del Ruiz volcano in 1985. There, a mudflow entombed the town of Armero, killing roughly 21,000 people in the dead of night.
On Mount Hood, “any little thing that happens could have a big consequence,” said Moran, scientist-incharge at the federal Cascades Volcano Observatory.
And yet the volcano is hardly monitored. If scientists miss early warning signs of an eruption, they might not know the volcano is about to blow until it’s too late.
Determined to avoid such a tragedy, Moran and his colleagues proposed installing new instruments on the flanks of Mount Hood in 2014. Those include three seismometers to measure earthquakes, three GPS instruments to chart ground deformation and one instrument to monitor gas emissions at four different locations on the mountain.
But they quickly hit a major hiccup: The monitoring sites are in wilderness areas, meaning that the use of the land is tightly restricted. It took five years before the Forest Service granted the team approval in August.
The approval is a promising step forward, but Moran and his colleagues still face limitations, including potential legal action that may block their work.
Such obstacles are a problem across the United States where most volcanoes lack adequate monitoring. Although federal legislation passed in March could help improve the monitoring of volcanoes like Mount Hood, scientists remain concerned that red tape could continue to leave them blind to future eruptions, with deadly consequences.
The United States is home to 161 active volcanoes, many of which form a line along the west coast through California, Oregon, Washington and Alaska. Seven of the 10 most dangerous American volcanoes are within the Cascade Range, and six of those are not adequately monitored.
In contrast, countries like Japan, Iceland and Chile smother their highthreat volcanoes in scientific instruments.
“The U.S. really doesn’t have anything to this level,” said Erik Klemetti, a volcanologist at Denison University in Ohio.
Yet there is no question that better monitoring could save lives. Volcanoes don’t typically erupt without warning. As Mount St. Helens awoke in May 1980, a series of small earthquakes could be felt on the surface nearby. Shortly thereafter, the volcano started to deform. Steam explosions sculpted a new crater, while a bulge emerged on the volcano’s north flank. Earthquakes continued, landslides rumbled and ash-rich plumes erupted all before the main event.
Although not all volcanoes follow such a steady, preeruptive pattern, they typically either tremble, deform or belch volcanic gases, meaning that if scientists monitor these three signals, they will likely be able to forecast when a volcanic eruption will happen.
Take Hawaii as an example. Shortly after earthquakes picked up at the Kilauea volcano on April 30, 2018, scientists at the Hawaiian Volcano Observatory could tell that they were not only increasing, but they were also propagating to the east.
Scientists used those signals to project where magma might erupt, and planners evacuated residents in that area. The eruption destroyed more than 700 homes, but remarkably no one died.
And it was all thanks to 60 seismic stations located across the island.