Lidar reveals the true faces of California's volcanoes
Volcanoes in California (and everywhere!) are often covered with vegetation, including thick forests. Fortunately, the USGS can use laser technology to cut through the canopy and reveal the geology...
View ArticleStratovolcano flank vents and the origin of Black Butte
You might envision a stratovolcano as one massive cone with a single summit crater. But in reality, volcanoes are complex constructions that may have multiple vents, even on their slopes.
View ArticleVisualizing volcanic volumes
Scale is very important to volcanologists - not just for photos, but when thinking about the relative size (or volume) of natural features.
View ArticleThe story of the faulted field: How Pinnacles ended up almost 200 miles north...
One of California's coastal volcanic fields, the Pinnacles volcanic field (or Pinnacles National Park) is an eroded collection of mostly rhyolite lava flows, intrusions, and pyroclastic breccias...
View ArticleRecent large earthquakes near Lassen are just another day in the Basin and Range
Since May 11, 2023, a series of M5+ earthquakes and aftershocks have rattled the area around Lake Almanor, a reservoir about 20 miles (32 km) southeast of the Lassen Volcanic Center.
View Article10 Ways Mount St. Helens Changed Our World
The 1980 eruption of Mount St. Helens had a profound impact on how we live with active volcanoes. Looking back over the last four decades, we have made great strides in understanding volcanic hazards...
View ArticleWhat makes Long Valley's resurgent dome reach for the skies?
While the huge caldera-forming eruption of Long Valley was 767,000 years ago, between about 670,000 and 570,000 years ago uplift of the caldera's floor formed a large mound. This is called a resurgent...
View ArticleHaving a (volcanic) field day in California
Today we feature volcanoes that are outstanding in their fields - volcanic fields, that is!
View ArticleWe're ready for our closeup! Filming virtual field trip stops in the Clear...
California Volcano Monitor: This past week, you might have seen a truck full of geologists toting video equipment around the Clear Lake Volcanic Field. While we're not debuting in Hollywood, we are...
View ArticleBubble trouble? Tracking changing hydrothermal features in Long Valley's Hot...
If you spend time in Long Valley, you may have noticed some changes in the Hot Creek springs and pools following this winter's dramatic snows. Fortunately, they're not a sign of volcanic unrest -...
View ArticleThe Mystery of the Noon Booms: Part 1
Just in time for the Fourth of July, CalVO scientists have been seeing some interesting - but unusual - acoustic signals on our seismometers.
View ArticleThe Mystery of the Noon Booms Part 2
In last week's post (https://www.usgs.gov/observatories/calvo/news/mystery-noon-booms-part-1), we challenged you to give us your best hypotheses as to what was causing the 'Noon Booms' CalVO...
View ArticleFall into a burning (curtain) of fire with fissure eruptions
If you've been following the latest geological news, you'll have noticed the brand new eruption on Iceland's Reykjanes Peninsula. It's a classic example of an eruption of relatively fluid lava...
View ArticleA CalVO library classic book: Dana's "Characteristics of Volcanoes"
As CalVO moves from its Menlo Park location to its new home at Moffett Field, scientists have the monumental task of deciding what to preserve and what needs a new home. And like all scientists, we...
View ArticleUSGS volcano scientists visit Long Valley
If you were visiting Long Valley this past week, you might have seen a cavalcade of SUVs periodically disgorging people wielding rock hammers, hand lenses, and brightly colored notebooks.
View ArticleGetting sphere-ious about spherulites
If you ever have the chance to visit the silica-rich Hot Creek rhyolite lava flow in the Long Valley Caldera, you might get the sense that you're being watched. The hills here don't have eyes, but...
View ArticleWhen it comes to calderas, how big is big?
Talking about calderas means venturing into superlatives - huge volumes of magma and topographic changes on a regional, even state-sized scale. But how do you put calderas - and the eruptions which...
View ArticleA brief history of the Lassen Volcano Observatory (1926-1935)
Before there was a California Volcano Observatory or even a Long Valley Observatory, a tiny cabin in northern California housed the first full-time volcano observatory outside of Hawaii: the Lassen...
View ArticleFinding the tempo of shield volcanism in California's Cascades
Though volcanoes like Mount Shasta or Lassen Peak may dominate their skylines, California also has shield volcanoes, named because their shape is reminiscent of a round warriors' shield resting flat....
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