Nearly 200-thousand people live, work or pass through California’s volcanic hazard zones on a daily basis. That is according to a new report broadly assessing areas that could be at risk from an eruption.
The impacts of an eruption, estimated to have a probability of 16 per cent in the next 30 years, would likely extend well beyond local areas due to effects on utilities, telecommunications, water and transportation systems.
The study was conducted by the US Geological Survey in cooperation with the California Governor’s Office of Emergency Services.
The research spotlights a natural hazard that receives less attention than wildfires, earthquakes, floods and landslides, which happen more frequently.
The most recent of at least ten eruptions in the past one-thousand years occurred at Northern California’s Lassen Peak from 1914 to 1917.
Lassen is one of eight volcanic areas up and down the state that are designated as having moderate, high or very high threat.
The group includes California’s most iconic volcano, snow-capped Mount Shasta, which towers over the landscape south of the Oregon border, and the less-recognisable Long Valley volcanic region on the eastern side of what is now Yosemite National Park.
They have the two largest populations for volcanic areas, about 100-thousand around Mount Shasta and more than 60-thousand around the four volcanoes in the Long Valley region.
Thousands of tourists also visit the parks surrounding the volcanoes every year and hundreds of passenger jets fly over California volcanoes daily.
But the report should not be taken as a “doomsday scenario,” said geologist Jessica Ball.
Instead researchers said it is a call for citizens and agencies to understand volcano hazards and to prepare for them.
