 California's Sleeping Giants, coming up next. Coming up on Inside Look. The explosion of a volcano erupting. California is not only earthquake country. It is also volcano country. More than 500 volcanic vents have been identified in the state of California. We know that there's a chance that they will occur, but we're not able to say exactly why. We're going Inside California's Earthquake Tsunami and Volcano Program this week on Inside Look. Cal OES Logo. Inside Look. OESNews.com. Welcome to Inside Look. I'm Brian May, and what you see behind me is 100% pure California. It is just absolutely beautiful, isn't it? But what our eyes can see on the surface only tells half the story. We know that California is home to earthquakes, but did you also know that we are a state home to volcanoes? Should we be worried? And how much notice would we get if there were to be an eruption? It's time to start answering those questions. We begin our coverage with Sean Boyd. Snowcapped Lassen Peak. Lassen Peak. Its beauty belies its simmering potential. It is at the top of the state's volcano watch list. The volcano is still very much active. That's why we have these wonderful hydrothermal areas. California is not only earthquake country. It is also volcano country. Dr. Maggie Mangan is the scientist in charge at the USGS California Volcano Observatory in Menlo Park. The threat is real and the potential for another volcanic eruption in the state of California is on the order of one in a hundred to about one in a couple thousand in any given year. Would you buy a lottery ticket with those odds? Well, those odds are why the USGS monitors all eight volcanoes in the watch list. Lassen Peak and Mount Shasta in the north and Long Valley Caldera east of Yosemite are California's high threat volcanoes. Monitoring stations at the volcanoes themselves gather seismic and gas readings, along with data on changes in land topography, then streams it all in real time to this operations room at the observatory. Scientists also watch the molten rock or magma flowing three miles below Lassen Peak. We keep a watch on that because if we start to see anything migrating toward the surface, it might suggest that the magmatic system is going to be replenished and that could provoke an eruption. Dr. Mike Klin has studied Lassen Peak since 1975. Lassen last erupted in May of 1915, miraculously captured on film. An old black and white flickering film shows a large plume at the top of the mountain. There were no known deaths and only a few minor injuries. But should Lassen or Shasta blow today and it will? It's not a matter of if, it's just a matter of when. The results would be more complicated and concerning depending on the severity and the other conditions like weather. But it would not take us by surprise. It's likely that you would see weeks to months of warning. Scientists learn a lot from history. It is a determined odds maker. The number of volcanic eruptions that occur within the state of California in just the last thousand years are about the same as the number of large damaging earthquakes on the San Andreas Fault. We take that hazard seriously. We need to take the volcano hazard seriously. Alright, thanks, Sean. So what's being done to monitor the volcanoes in California? How do we know that we'll know before the next eruption? With more on Cal OES's role in volcano monitoring, here's Jonathan Goodell. Thanks, Brian. If there's anything that we've learned about volcanoes, it's that they're impulsive. When and where they may erupt is virtually impossible to predict. What we do know is that monitoring is being done around the clock to ensure public safety. Tracking indicators such as GPS, seismometers and other tools provide experts with a realistic assessment of when a volcano may erupt. Warnings could spare residents a few days, weeks and maybe months, even as threats rise. There's a notification process that we use with our federal partners which rise all the way from an advisory up to an imminent morning. Through the earthquake, tsunami and volcano program, Cal OES monitors reports from the USGS including low-magnitude earthquakes. Over time, those earthquakes could be an inclination of an impending volcanic eruption. We work very closely with our scientific partners at the California Geologic Survey and the US Geologic Survey to really understand what the hazard is. So that includes digging in deep to what the mapping is right now and also learning about what the implications would be once a volcano eruption were to occur and how that would impact not only the local communities but the secondary and tertiary cascading impacts that could happen as a result of a volcanic eruption. What can be done to minimize impacts to your family and home? First, be aware of any surrounding volcanoes and how close you are to them. Also, review your homeowner's insurance policy, be aware of warning sirens and create an emergency evacuation plan as well as an emergency kit. Because the odds of the next volcanic eruption happening? Well, even for the experts, it's just too unpredictable. There are some volcanic eruptions where, you know, it could be tens of thousands of years in between when the last one erupted. So we're still continuing to be vigilant and making sure we're monitoring and staying on top of all the latest science so we can be prepared for when that day does happen. Here are some interesting facts about volcanoes. Did you know Kilauea in Hawaii is the most dangerous volcano in the world with 61 eruptions since 1893? The largest volcanic eruption on record was Toba in Indonesia, thought to have erupted 73,000 years ago. It released more than 1,000 cubic kilometers of material and created a caldera 100 kilometers long and 30 kilometers wide. The United States ranks third behind Indonesia and Japan in the number of historically active volcanoes. And there are 65 volcanoes in the United States with eight of those in California alone. And lastly, Mount St. Helens was a most destructive eruption in U.S. history, occurring in 1980 in Washington state. Thanks, Jonathan. To see more videos like this and to see other stories covered by our team, you can go to oesnews.com. You can also like our Facebook page and follow us on Twitter and Instagram. And that will do it for this week's edition of Inside Look for all of us at Cal OES. I'm Brian May. Thanks for watching and stay safe.