| Agency Name: | United States Geological Survey Cascades Volcano Observatory |
| Headquarters: | Vancouver, Washington, USA |
| Formed: | 1980 |
| Chief1 Name: | Dr. Jon Major[1] |
| Chief1 Position: | Scientist-in-Charge (USGS) |
| Website: | https://www.usgs.gov/observatories/cvo |
The David A. Johnston Cascades Volcano Observatory (CVO) is a volcano observatory in the US that monitors volcanoes in the northern Cascade Range. It was established in the summer of 1980, after the eruption of Mount St. Helens.[2] The observatory is named for United States Geological Survey (USGS) volcanologist David A. Johnston, who was swept away in the Mount St. Helens eruption on the morning of May 18, 1980.[3] The observatory's current territory covers Oregon, Washington, and Idaho. The Cascade Range's extent includes northern California, and Cascade volcanoes in that state, such as Mount Shasta and Lassen Peak, previously fell under the CVO's jurisdiction. However, these volcanoes now fall under the jurisdiction of the California Volcano Observatory (CalVO), formed in February 2012 and based in Menlo Park, California, which monitors and researches volcanic activity throughout California and Nevada.[4]
The Cascades Volcano Observatory is part of the USGS, a scientific agency of the United States government.[5] It is located in Vancouver, Washington in the Portland, Oregon metropolitan area.
This list shows volcanoes currently monitored by the Cascades Volcano Observatory, which range in order of highest to lowest risk assessment.
According to USGS risk assessment of volcanoes located in the northern Cascades region, the following volcanoes were ranked "very high threat potential".[6]
The following volcanoes were ranked "high threat potential":[6]
The following volcanoes were ranked "moderate threat potential":[6]
The following volcanoes were ranked "Low to Very Low Threat Potential":[6]
There are other volcanoes in the northern Cascades region that have not been assessed one of these risk levels which warrant monitoring. Volcanoes that have not erupted during the Holocene period were not included. USGS has noted, though less probable, that it is still possible for volcanoes to erupt on longer intervals than mentioned.[6]