Eruption:The Untold Story of Mount St. Helensby Steve OlsonWW Norton, 2016The eruption of Washington State's Mount St. Helens in 1980, as Steve Olson writes in his completely captivating new book Eruption, was the single most powerful natural disaster in US history: “more powerful than Hurricane Katrina when it hit New Orleans in 2005, more powerful than the 1906 earthquake that destroyed San Francisco, more powerful even than the world's first atomic explosion on the high plains of New Mexico in 1945.” It spewed ash for miles in all directions, and the fact that it only resulted in the deaths of fifty-seven people was largely due to the fact that he happened on a Sunday morning. As Olson points out, had it happened at the same time a day later, many thousands of people would very likely have died.Eruption tells the full story of that historic event – and leans more toward the geologic meaning of 'full' than the human meaning of the term. The opening chapters of his book alternate between introducing readers to his 1980 cast of geologists like Keith and Dorothy Stoffel or Dave Johnston – people who were studying Mount St. Helens precisely because the mountain was giving off signs of intense and potentially violent activity – and figures from a century ago, studying the whole mountain range for the first time. Any author writing about a modern event who insists that Theodore Roosevelt and Gifford Pinchot take a turn around the stage is most certainly giving you the deep background on his subject.In a way, it's an understandable problem that's been plaguing chroniclers of volcanic eruptions since the days of Vesuvius: the actual heart of the catastrophe happens a bit too quickly to fill out a book all by itself. Instead, writers need to fill in plenty of context before they destroy it with fire and ash. The test comes in how effective a job the authors do in all that scene-setting. The flesh-and-blood believability of the cast of characters is the main reason for the success of novels like Robert Harris's Pompeii or Bulwer-Lytton's The Last Days of Pompeii. And it's a mark of Olson's own success that the first books that come to mind when estimating the dramatic punch of Eruption are novels.But through painstaking research, Olson is in these pages instead giving us popular nonfiction at its most energetic, especially when he arrives at the heart of his story, the sudden bulging and explosion of Mount St. Helens on a beautiful clear Sunday morning. The eruption found Keith and Dorothy Stoffel in the air in a small plane flying straight toward the mountain – giving them an unprecedented sight:

Then, as they looked out the plane's windows, an incredible thing happened. A gigantic east-west crack appeared across the top of the mountain, splitting the volcano in two. The ground on the northern half of the crack began to ripple and churn, like a pan of milk just beginning to boil. Suddenly, without a sound, the northern portion of the mountain began to slide downward, toward the north fork of the Toutle River and Spirit Lake. The landslide included the bulge but was much larger. The whole norther portion of the mountain was collapsing, The Stoffels were seeing something that no other geologist had ever seen.

More touchingly, Olson is also able to piece together, as much through empathy as record-sifting, the Sunday morning experience of people not quite so fortunate as the Stoffels, like researcher Dave Johnston, who was on the ground and too close to the cataclysm to do anything about his own survival:

As Johnston watched the volcano, the blast cloud quickly obscured the ongoing avalanche. The front of the cloud was magnificent. It was like an immense oncoming waterfall with great blocks of earth and ice cascading from far overhead. The base of the blast cloud reached the ridge on which he was standing and started up the side. Johnston could have tried to take shelter. He might have run inside the trailer, thinking he could survive. But by the time the blast reached the ridge, he must have known he wouldn't live. It is certainly possible that he stood and watched the oncoming holocaust.

Eruption cannot help making some narrative gestures at our present-day state of relaxation in 2016. The United States is home to 169 active volcanoes, 59 of which are ranked by the US Geological Survey as “high” threats, and it only takes reading about the combination of lucky factors that caused Mount St. Helens to cause so little loss of life 40 years ago to realize that the country will almost certainly not be so lucky a second time. If California's Mount Shasta or Hawaii's Mauna Loa – to say nothing of the Yellowstone supervolcano in Wyoming – were to erupt as violently and suddenly as Mount St. Helens did back in 1980, the consequences would most likely make for a far grimmer book than this one.