Wilderness vs. Monitoring: The Controversy of a New Seismic Network at Glacier Peak

Glacier Peak in Washington. Wikimedia Commons. One of the most potentially dangerous volcanoes in the Cascades is Glacier Peak in Washington. It produced the one of the largest eruptions in the past 20,000 years in this volcanic range that spans from British Columbia to California. Multiple eruptions around 13,500 years ago spread ash all the way into Montana. Over the last 2,000 years, there have been multiple explosive eruptions that have impacted what became Washington state and beyond. Put on top of that the many glaciers on the slopes of Glacier Peak that could help form volcanic mudflows (lahars) during a new eruption, and you can see that Glacier Peak is a real threat. Yet, even with this hazard posed by the volcano, there is very little in the way of monitoring equipment on the volcano. Currently, there is a lone seismometer on Glacier Peak to measure earthquakes, one of the most important pieces of information needed to monitor volcanoes. A single seismometer is better than no seismometer, but it can only give us so much information. Without a network of at least 3 seismometers (a"seismic network"), we can really only measure if earthquakes are occurring at the volcano and not exactly where and how far beneath the volcano the temblors are happening. This is what is installed at a truly restless volcano like Mount St. Helens. These two pieces of information -- location and depth -- are vital for understanding what might be happening at Glacier Peak if any earthquake swarm were to happen. Otherwise, we might have difficulty differentiating between earthquakes happening due to fault motion near the volcano or shallow changes in the hydrothermal system in the volcano rather than magma moving into the volcano from deep below.