Kīlauea, Hawaii 2. Why California Volcanoes are a Threat. The National Volcano Early Warning System (NVEWS) is a proposed national-scale plan to ensure that volcanoes are monitored at levels commensurate to their threats. The volcano last erupted roughly 3,800 years ago and remains a high threat volcano, with lahars being the biggest threat to communities downslope from the … Additionally, a lot of critical utility infrastructure is located within these at-risk areas. Of the 18 volcanoes posing a very high threat, three are located in California. Reports from USGS and the California Volcano Observatory are used to inform the state's Volcano Preparedness Plan, which is part of California's greater emergency plan. Redoubt Volcano… Roughly half of the Nation's 169 young volcanoes are dangerous because of … A new report issued by the U.S. Geological Survey has classified 18 volcanoes in the U.S. as “very high threats,” including three in California.The agency said a dozen volcanoes … Eleven of the 18 very high threat volcanoes are in Oregon, Washington and California. The 18 volcanoes included in the “very high threat” category are: 1. Most people (myself included before reading this article) are simply not aware that California has any volcanoes, but surprisingly the state has 12 of them! The plan was developed by the U.S. Geological Survey (USGS) Volcano Hazards Program (VHP) and its affiliated partners in state and academic institutions. Mount St. Helens, Washington 3.

California is used to earthquakes. But there’s a “very high threat” volcano looming less than 100 miles from Fresno

Volcanoes - not so much.

About 200,000 residents and visitors are within a volcano hazard zone every day. Public Information Officer Shawn Boyd of the Office of Emergency Services says the agency incorporates the threat of California's volcanoes into their emergency response planning.

But there's another deadly threat that is is almost as likely -- and that people may be much less prepared for.Within the next 30 years, there's a 16 percent possibility of a small to moderate-size volcanic eruption occurring somewhere in California, according to a U.S. Geological Survey (USGS) report posted Monday (Feb. 25). Mount Rainier, Washington 4. The state also has four volcanoes on the high threat list and another four on the moderate threat list.