Mount Shasta, a steep-sided Cascade Range stratovolcano in Northern California, looms above Little Glass Mountain, a thick obsidian flow erupted from the Medicine Lake shield volcano about 1,000 years ago. These are just two of the young volcanic areas monitored by the USGS California Volcano Observatory. (USGS photo)

National Volcano Early Warning System Puts Laser Focus on America’s Most Dangerous Magma

In September 2004, USGS scientists detected sudden, but unmistakable, signs that Mount St. Helens was waking up. Volcano monitors had picked up the occurrence of hundreds of small earthquakes and other signals that the volcano’s crater floor had begun to rise. Within a week, several eruptions blasted clouds of ash into the atmosphere, and soon after, a new lava dome emerged in the crater.

But as volcanic activity escalated, it became clear to scientists at the USGS Cascades Volcano Observatory (CVO) that the 20-year-old equipment and monitoring network capabilities were insufficient to properly forecast possibly severe eruptive activity. During the eruption, USGS CVO scientists grew increasingly concerned as ground shaking caused seismic signals to go off the scale on the outdated seismometers. Additionally, only one of the two continuously recording GPS receivers was operational. Had there been a half dozen or more GPS receivers installed around the volcano, scientists would have been able to triangulate the location of magma and develop models that showed the location and volume of magma over time.

Scientists scrambled to borrow and install modern instruments and create new technologies on-the-fly, but they were dismayed to discover that the old system used for transmitting data was not compatible with the more modern borrowed equipment. Under the scrutiny of intense worldwide media interest, the USGS was playing catch-up with the volcano while a potentially hazardous situation unfolded. Being ill-equipped to forecast volcano hazards, especially in the midst of a crisis, is risky business. Something needed to be done to avoid this situation in the future.

Volcanologists at the five USGS volcano observatories across the nation worked together to assess what was critically needed to fulfill the USGS’s mandate to properly forecast volcano hazards and to reduce their impacts on communities, people, and infrastructure. By 2005, scientists examined the hazards posed by the nation’s volcanoes and ranked their relative threat level. Through this effort, scientists discovered that two-thirds of the country’s active volcanoes were insufficiently monitored, including most in the moderate- to very high-threat categories. This volcano threat assessment showed that the USGS lacked the data necessary to make timely forecasts and to issue warnings to people and communities.

In 2018, the USGS released an updated National Volcano Threat Assessment for the United States that showed 18 U.S. volcanoes are ranked as very high-threat, 39 are high-threat, and 51 are moderate-threat. The volcanoes are all located in states west of the Rocky Mountains, including in Alaska and Hawaii. The threat assessment helps guide decisions about how to strengthen volcano monitoring networks and bolster hazard preparedness and emergency response.


In March 2019, Congress passed the John D. Dingell Jr. Conservation, Management, and Recreation Act (PL 116-9/S.47). Section 5001 of the bill authorized the USGS to establish a National Volcano Early Warning System, or NVEWS. The system has been designed to “monitor, warn, and protect citizens of the United States from undue and avoidable harm from volcanic activity.” With NVEWS in place, scientists will be able to make sure all dangerous U.S. volcanoes are monitored at levels consistent with the threat that they pose to communities, infrastructure, and aviation.

“Improvements to volcano monitoring networks allow the USGS to detect volcanic unrest at the earliest possible stage,” says Tom Murray, the USGS Volcano Science Center director. “This provides more time to issue forecasts and warnings of hazardous volcanic activity and gives at-risk communities more time to prepare.”

What specifically is included with NVEWS? First, it lays the foundation for the USGS to modernize and expand volcano monitoring networks nationwide to help keep people and communities safer by providing warnings and forecasts before dangerous volcanic events occur. The volcano observatories plan to employ broadband seismometersinfrasound arrays, real-time continuous GPS receivers, streaming and near-real-time webcams, and real-time volcanic gas sensors, plus satellite imagery and other remote-sensing techniques. Additionally, new networks will be installed on under-monitored, but high-risk volcanoes such as Mount Baker in Washington. Standardized digital telemetry systems will tie the networks together and make data communication consistent across all observatories.

When fully implemented, NVEWS will be an effective nationwide volcano-monitoring and hazard-warning system that will quickly and accurately identify volcanic events and deliver actionable information to people so that they can be better prepared. Monitoring stations with multiple instruments are planned for the nation’s high- and very high-threat volcanoes.

Read more at the U.S. Geological Survey

America’s 18 Most Dangerous Volcanoes Based on Threat to People, Property

The Government Technology & Services Coalition's Homeland Security Today (HSToday) is the premier news and information resource for the homeland security community, dedicated to elevating the discussions and insights that can support a safe and secure nation. A non-profit magazine and media platform, HSToday provides readers with the whole story, placing facts and comments in context to inform debate and drive realistic solutions to some of the nation’s most vexing security challenges.

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