100 years and counting

It’s the centennial of Lassen Peak’s eruption, and scientists say another North State blast is bound to happen

Downtown Red Bluff 1915

Downtown Red Bluff 1915

Photo by R.E. Stinson/courtesy of National Park Service

Celebrate the centennial:

The Lassen Peak Eruption Celebration runs from May 22-25 and features several special presentations by park personnel and USGS scientists, including Clynne. For a full event schedule, go to www.nps.gov/lavo/planyourvisit/centennial.htm

On the night of May 19, 1915, Elmer Sorahan was having a helluva time getting some much-needed rest in the tent he’d set up alongside Hat Creek, a few miles northeast of Lassen Peak. Every time he’d get close to falling asleep, his dog would whine, growl, jump and paw at him until he sat up, alert. His canine companion grew more agitated as the midnight hour approached, and Sorahan, believing that perhaps a bear or panther was near, finally accepted the warning and peeked out to see what was afoot.

Downtown Red Bluff 2015

Photo by Ken Smith

The 25-year-old homesteader heard the approaching danger before he saw it, a “cracking-popping” sound of rocks being pushed down the creek by a deluge of water, mud and other debris. As Sorahan shook off his weariness and noticed ripples on the nearby creek rising, he wisely decided the time had come to run, which he proceeded to do immediately, without pausing to lace up his boots.

Sorahan escaped the torrent but realized that, without warning, others downstream might not be so lucky. He raced to the home of his nearest neighbor, Wid Hall, who lived with his family 3 miles down the creek. Hall’s wife, Emily, had just enough time to call the Hat Creek ranger station and spread the warning before gathering the family and, as her husband put it, “beat it for higher ground.” Upon returning the next morning, the Halls found their home lodged between a tree and a broken fence more than 50 feet from where it originally stood, filled with 2 1/2 feet of mud.

The May 19 late-night eruption that caused the mud flows— at that point the largest in a series of volcanic activity that had begun at Lassen Peak a year earlier, on Memorial Day (May 30), 1914—was just a precursor of what was to come. At around 4 p.m. on Saturday, May 22, Lassen Peak erupted in spectacular fashion, sending a plume of ash, steam and smoke—visible from Sacramento and Eureka—30,000 feet into the air. Lava spilled over the broken ridge of Lassen’s crater, mixing with mud, rock and other debris and melting that year’s heavy snows to create even more damaging lahars (mud and volcanic material flows) that reached the Pit River and killed off large numbers of fish.

Near the mountain, volcanic gasses were ejected with such force that the few ancient pines that had survived the week’s earlier blast snapped like matchsticks in a 3 square mile swath on Lassen’s northeast slope now officially known as the Devastated Area. Rocks and boulders that remained hot to the touch for days afterward were flung hundreds of yards through the air, and ash fell more than 200 miles to the east, in Winnemucca, Nev. The eruption continued intermittently well into the night.

Prior to Lassen Peak’s rumblings, which continued to a lesser degree until 1917, the entire Cascade mountain range had been declared long dead by the day’s leading scientists. Lassen was the first volcano to erupt in the lower 48 since the beginning of written history in the Western U.S., and held the distinction of being the only “active” volcano in the contiguous United States until Mount St. Helens’ 1980 eruption.

Lassen Peak’s eruptions between 1914 and 1917 were the first to be widely photographed. Benjamin Franklin Loomis lived in the Lassen region and kept his camera handy as he explored the area.

Today, the area around the peak is known as Lassen Volcanic National Park, which will celebrate the big blast’s centennial beginning this weekend, and throughout the summer. The park is a “living laboratory” at which volcanism and geothermal activity are constantly observed.

One hundred years is just a sliver of time considering the volcanic and geological history of the immediate area, and that of all of Northern California. Studying this history, and current conditions at the park, indicate future eruptions are a certainty, though when and where is still unknown. As a sign at the park’s Kohm Yah-mah-nee Visitor Center (using the Maidu name for Lassen Peak, “Snowy Mountain”) reads, “the land is restless and one day, as sure as you stand here, these mountains will roar to life once again.”

Some reports of the damage to property caused by Lassen Peak’s eruptions were greatly exaggerated in the local press. There were tales of 3,000 head of cattle killed, fertile farmlands poisoned by volcanic mud flows and Hat Creek refugees who shuddered in terror at the thought of returning to their homes. A Redding newspaper, then called The Searchlight, declared, “Mountain vomits lava and mud, hundreds flee for their lives” when reporting the May 22 eruption, and some of the headlines grew more spectacular—and downright strange—in the days to come. An article in that same paper a few days later with the headline “Epidemic of craziness seizes Anderson people” concludes, “It is probable that there will be an exodus from this county to the insane hospitals, after the examinations are held. Several theories are advanced as to the cause and effect, but that most generally accepted is the belief that Mount Lassen’s activities have proven too great a mental strain for those to the south.”

There are, however, many reliable reports and records of the damage. The eruption occurred during the advent of amateur photography, making Lassen’s volcanic activity some of the first to be captured on film. History owes a particular debt of gratitude to Benjamin Franklin Loomis, a businessman and photographer from nearby Viola who collected many of his and others’ photos, field notes, some of the more accurate news articles, and first-hand accounts of the eruptions from Lassen area residents, compiling them into a book alternately titled The Pictorial History of the Lassen Volcano or Eruptions of Lassen Peak and originally published in 1926.

Property damage resulting from the May 19 and 22 eruptions totaled about $5,000 (about $116,199 today). In addition to damaged or destroyed homes and farms, roads and bridges were washed out. No cattle were actually lost—just a couple of chickens, according to Loomis’ sources. No one was killed, although there were close calls as adventurers and sightseers explored the park before and after the late-May climactic eruptions. Loomis’ book includes an article from another Redding newspaper, the Shasta Courier, relating how a young man named Lance Graham was hit in the head by a rock flung from the crater while hiking Lassen Peak during a small eruption. He was temporarily paralyzed and unable to speak as his friends—believing he was dead—dragged him back down the mountain.

Sulphur Works, which features boiling mud pots and steaming fumaroles, is one of many active geothermal areas in the park. Visitors are warned to stay on trails and boardwalks to avoid breaking through the ground and being burned by boiling, acidic mud and water.

Photo by Ken Smith

Though no one was killed and loss of property was minimal, damage to the natural environment was significant. The lead ranger at the time reported the loss of 5 million feet of timber. A pair of reporters from the Stockton Record observed the May 22 eruption from outside Lincoln (150 miles away) en route to Lassen, and spent a few days touring and reporting actual damages, led for some time by Loomis. Observing the damage in the Lost Creek area, a few miles north of the volcano, they wrote, “We saw sufficient examples of wreck and ruin to make one lie awake at night for weeks.

“We hardly expect every Record reader to believe all this story. You can’t believe it unless you see it.”

By modern estimations, the 1915 eruption was relatively small in the scheme of volcanic activity, according to Michael A. Clynne, a geologist with the U.S. Geological Survey based in Menlo Park. Clynne’s career as a geologist began as a field assistant in Lassen park in 1976, and he spent eight to 10 weeks there annually for more than a decade. Clynne’s not just an expert on the Lassen area and its volcanic history; he’s the expert who writes USGS fact sheets about Lassen Volcanic National Park and the surrounding areas.

“In terms of most modern eruptions that anyone would pay much attention to, it was tiny,” Clynne said in a recent phone interview. “We typically measure the size of eruptions by the amount of material that was erupted. In 1915, that volume was .03 cubic kilometers, whereas Mount St. Helens was about a cubic kilometer or so … 30 to 50 times bigger. There have been big eruptions in the past, but 1915 wasn’t that big.”

Other recent eruptions in the Lassen region happened at Chaos Crags about 1,100 years ago, and Cinder Cone in 1666, according to radiocarbon dating on a tree killed by lava from that blast. Lassen Peak itself was formed when it initially exploded about 27,000 years ago, Clynne said. The whole Lassen area is on the base of a much larger, now eroded stratovolcano active between 700,000 and 385,000 years ago called Mount Tehama, which Clynne estimates was about one-quarter the size of Mount Shasta; remnants of Mount Tehama include Brokeoff Mountain, Pilot Pinnacle, Mount Diller and Mount Conrad.

Effects of Lassen Peak’s May 1915 eruptions.

Map courtesy of U.S. Geological Survey

Piecing together this history is how geologists predict future volcanic activity, Clynne explained: “The Lassen volcanic center is active and will erupt again; it’s just a matter of time. If you want to look at that statistically, over the last 100,000 years the center has had an eruption about every 7,500 years. But, there have been three eruptions in the last 1,100 years, so you clearly can’t use that average. Also, eruptions tend to occur in episodes.

“I like to compare volcanoes to people,” Clynne further explained. “Everyone has a different personality, and you can think of volcanoes that way. How we learn about their personalities is to study their eruptive history. It gives us a very good idea of what to expect when the next eruption happens or is impending, but we’re not always right on that because, like people, volcanoes can do new stuff. But they’re much more likely to do something they’ve done in the past than they are to do something new.”

Part of the area’s volcanic personality is that eruptions don’t often occur in the same place twice. Clynne said he believes Lassen Peak’s 1915 eruptions were “accidental,” in that “some new batch of magma used an old conduit to get to the surface,” and explained it’s much more likely for an eruption to occur in a new place, perhaps even from an area that the general public doesn’t recognize as a volcanic threat.

“The area between the southern valley of Lassen park up to the Pit River, where Burney is, virtually every mountain in that area is a volcano,” Clynne said. “The entire surface of the land is covered with volcanic rocks 2 or 3 kilometers thick. They’re mostly what we call monogenetic, meaning they erupt only once and they’re done, but there are certain areas that have had more young eruptions and will likely produce new volcanoes.”

Predicting eruptions is far from an exact science, but Clynne said his best guesses for new eruptions would be in the north end of the Caribou Wilderness (east of the Lassen Volcanic Center) or near Tumble Buttes (midway between Lassen Peak and Burney).

Rachel Teasdale teaches volcanology at Chico State, and last semester charged her students with preparing public presentations on the history and geology of Lassen Volcanic National Park to commemorate 100 years since the latest eruption. One of her pet peeves is the use of the term “Mount Lassen”—the volcano’s official name is Lassen Peak.

Photo by Ken Smith

Chico suffered very few physical effects from the 1915 eruption, and likely wouldn’t be affected by future eruptions from the area: “Chico is kind of like Portland is to Mount St. Helens,” Clynne said. “It’s too far away and in the wrong direction.”

News reports from 1915 confirm that Chico was unscathed, but got a good show. In a front-page roundup of information from various points in the North State following the big eruption, the then-Chico Enterprise reported, “Saturday afternoon’s eruption was seen by thousands of Chico people and many of them saw flames shoot from the mountain after nightfall … The Esplanade was crowded with autos and other vehicles and everybody who could got out where they could get a good view of the volcano in action.”

But what about all the volcanic rocks littering our area, which many people assume—or have heard through local lore—came from Lassen Peak a century ago, or from more ancient eruptions at Mount Tehama?

“That’s a common misperception, and I emphasize the ‘miss,’” said Rachel Teasdale, a volcanology professor at Chico State. I heard that when I first moved here and thought, ‘Gosh, that doesn’t seem plausible.’”

Teasdale specializes in research regarding the cooling and crystallization of lava flows, work that has taken her around the world to witness several volcanic eruptions. She recalled the most exciting of these was a 1998 trip to Volcán Cerro Azul in the Galápagos Islands.

Todd Jesse, a guide at Lassen Volcanic National Park, will lead some of the special tours offered during the anniversary of Lassen Peak’s last eruption.

Photo by Ken Smith

“It was one of those cases when [the eruption] built a brand new cone that wasn’t there before, and the eruption wasn’t predicted; it just happened,” she recalled. “I jumped on a plane, then a boat, and another boat and so forth, and it was quite an adventure just to get down there. Then I hiked in to see the eruption happening—lots of cinders being launched into the air, fire fountaining, active lava flows—it was spectacular visually, and the adventure aspect was very cool, and it turned into some interesting research, so that trip had all the aspects of why I’m a volcanologist.”

Chico sits at the western end of the Tuscan Formation, Teasdale explained, which is the eroded bones of yet another ancient stratovolcano active millions of years ago called Mount Yana. She said Mount Yana stood roughly where Highways 32 and 36 meet today, and was “likely similar in size to what Mount Shasta is now, plus or minus a lot … there’s a lot of room for error when all you have is erosional remains.” Though sometimes mistakenly called “the lava cap,” the formation is not made from solidified lava, but rather from debris flow from Mount Yana’s eons-long breakdown.

“You can see intact debris flows in the buttes or ridges along Highway 32 or in Upper Park. In some places, the finer grain materials—sediments between boulders—flowed away but there wasn’t enough water to move the bigger rocks and boulders. They got stranded, so we call them ‘stranded boulders.’ So they were never launched up into the air to fly great distances; they just kind of rolled and tumbled to where they are now.”

So Chico likely would be safe from an eruption near Lassen, and hasn’t been affected by volcanic activity in the past several million years, but the experts agree that other localities might not be as fortunate if an eruption of similar magnitude occurred in the Lassen region today. As Clynne and USGS colleague Patrick Muffler summarize in the current Lassen park newsletter, bridges and roadways could be cut off and compromised, as could local water supplies and hydroelectric facilities. Additionally, railways likely would be cut off, and commercial flight traffic could likely be affected by smoke and ash. Another hazard would be wildfires.

“It would be significantly different if such an eruption occurred now,” said Todd Jesse, a Lassen park guide. “Back in the day, Northern California wasn’t nearly as populated; there were really only a couple of people around here.”

Wildlife in the park includes black bears, bald eagles and mountain lions. Those animals are elusive and rarely seen, but Steller’s jays and golden-mantled ground squirrels in the park’s picnic areas aren’t at all shy.

Photo by Ken Smith

However, Clynne also predicted that the study of volcanoes has advanced so far that they would have weeks’ or months’ notice before a significant explosion. Geothermal areas within the park are monitored for the release of increased volcanic gasses that would herald an eruption, and GPS ground-tracking technology is sophisticated enough to detect slight movements in the earth’s surface that would indicate magma swelling underground.

“We’d have plenty of notice to evacuate people safely,” he said, noting that even the 1915 eruption was preceded by a year of lesser activity. “Even the casualties from Mount St. Helens were from people who were in places they weren’t supposed to be.”

An undeniably positive effect of the 1915 eruption was the attention it brought to the region. For a time, Lassen Peak was America’s most famous mountain and only known active volcano, which helped it to become one of the first areas designated as a national park in August 1916, a week before an act of Congress established the National Park Service (Teddy Roosevelt had declared Lassen Peak and Cinder Cone as national monuments earlier, in 1907). Lassen Volcanic National Park is not just celebrating the eruption’s centennial, but gearing up to join nationwide centennial celebrations throughout the park system in 2016.

The volcano-loving Teasdale is quick to extoll Lassen park’s many virtues when asked about her favorite features.

“The coolest thing about the park is its diversity,” she said. “I love going to the Devastated Area and seeing how it’s changed in just 100 years. That’s fascinating to me; not just the devastation, but the regrowth. I love being up on top of Lassen Peak because the surrounding area is so spectacular from the top. I also really like the Cinder Cone area, because most of my research is on basalt lava flows like the kind found there. I’m attracted to that area for scientific reasons, and it’s also an exciting place to bring students so they can see the result of a [relatively] recent eruption and visualize what it was like when it erupted.

“Sulphur Works and Bumpass Hell are great reminders that there’s still hot magma in the subsurface below the Lassen Volcanic Center as you can see the groundwater heated up and coming through steaming mud pits and fumaroles.

“Can I say it’s all my favorite?”