In a jaw-dropping revelation, researchers from Caltech have brought to light that one of California’s most perilous volcanoes is demonstrating unsettling signs of activity, leaving experts to question whether a cataclysmic eruption is imminent.
The volcano in question, Long Valley Caldera, nestled in the scenic Mammoth Lakes area in Mono County, has been classified as a “very high threat” by the U.S. Geological Survey in 2018. This alarming designation places it alongside two other Californian giants, Mt. Shasta and Lassen Volcanic Center, in the most dangerous category of volcanoes in the country.
For decades, the Long Valley Caldera has exhibited a series of geological transformations and seismic unrest, typically indicative of an impending volcanic eruption. However, researchers have cautiously stated that a supervolcanic explosion, the likes of which could reshape the entire state, is not expected. But the question remains: What is causing these unsettling disturbances beneath the Earth’s surface?
Situated approximately 200 miles east of San Francisco and 250 miles north of downtown Los Angeles, the Long Valley Caldera is a massive depression formed when an underground magma chamber erupted or drained, resulting in a catastrophic collapse of land. This spectacular caldera was birthed from a super-eruption approximately 760,000 years ago, unleashing 140 cubic miles of magma and blanketing east-central California in a hot, ashy inferno.
Over the past four decades, this region has witnessed a surge in earthquake activity and ground deformation, igniting concern among scientists. The May 1980 sequence of four magnitude 6 earthquakes in the Long Valley area serves as a stark reminder of the potential power lurking beneath.
While fluctuations in the ground’s shape and seismic tremors are often precursors to volcanic eruptions, they do not guarantee an imminent explosion. However, this recent uptick in activity has prompted scientists to dig deeper, seeking answers to the ominous question: Is a supervolcanic eruption on the horizon?
The Caltech team, armed with an arsenal of seismometers, earthquake data, and cutting-edge machine learning algorithms, has reconstructed high-resolution underground images to decipher the mysteries beneath the Long Valley Caldera. Their conclusion? The increased seismic activity and ground deformation are more likely a result of the cooling and crystallizing magma, releasing gases and liquids that trigger earthquakes and smaller eruptions.
Despite these findings, some scientists remain skeptical, suspecting that the Long Valley Caldera may be a dying volcano, its increased seismic activity fueled by non-magma fluids moving to the surface. Yet, others argue that this sleeping giant is very much alive.
Emily Montgomery-Brown, a renowned USGS research geophysicist and an expert on the Long Valley Caldera, emphasizes that while the magma reservoir may be cooling, there are still “extremely young lava flows” nearby, hinting at other pockets of magma in the vicinity.
Furthermore, the Long Valley Caldera remains a significant seismic threat, capable of unleashing powerful earthquake swarms with potentially devastating impacts. California’s other volcanoes, too, pose grave risks, with eruptions capable of disrupting electricity supply, travel, air traffic, and water supplies across the state.
California’s last major volcanic calamity unfolded over a century ago, when Lassen Peak erupted between 1914 and 1917, creating a colossal mushroom cloud and spreading volcanic ash as far as 280 miles. Today, as the ground beneath Long Valley Caldera stirs once again, scientists and residents alike are left to ponder: Are we on the brink of California’s next great volcanic disaster?