- A dormant supervolcano has experienced increased seismic activity over the years
- Experts identified more than 2,000 quakes throughout the Long Valley Caldera
- READ MORE: California’s deadly ‘Big One’ could be caused by volcanic eruptions
The California supervolcano that could bury Los Angeles in more than 3,000 feet of ash is showing signs of activity.
Scientists at the California Institute of Technology (Caltech) identified over 2,000 earthquakes throughout the Long Valley Caldera in recent years.
The team conducted a new investigation to determine whether the seismic activity was a sign of impending doom or whether the risk of a massive eruption was decreasing.
Caltech researchers created detailed subsurface images of the caldera and determined that recent seismic activity is due to fluids and gases released as the area cools and settles.
Scientists at the California Institute of Technology (Caltech) identified over 2,000 earthquakes throughout the Long Valley Caldera in recent years
Study author Zhongwen Zhan said: “We do not believe the region is preparing for another supervolcano eruption, but the cooling process could release enough gas and liquid to trigger earthquakes and small eruptions.”
“In May 1980, for example, there were four magnitude 6 earthquakes in the region alone.”
A critical finding of the images revealed that the volcano’s magma chamber is covered by a hardened cap of crystallized rock that forms when the liquid magma cools and solidifies.
The long-dormant volcano was the site of a super explosion 767,000 years ago that released 140 miles of volcanic material into the atmosphere and devastated the land.
A critical finding of the images revealed that the volcano’s magma chamber is covered by a hardened cap of crystallized rock that forms when the liquid magma cools and solidifies
Zhan and his team placed dozens of seismometers throughout the Eastern Sierra region to collect seismic measurements in a process called Distributed Acoustic Sensing (DAS).
They covered 62 miles of the caldera with cables to take underground snapshots.
Over a year and a half, the team used the cable to measure more than 2,000 seismic events, most of which were too small to be detected by humans.
A machine learning algorithm then processed these measurements and developed the resulting image showing the locations of each quake.
Emily Montgomery Brown, A Long Valley Caldera expert who was not involved in the study told the LA Times that the earthquake swarms began in 2011.
These quakes were then followed by ground deformation that caused the land to rise and the tremors subsided in 2020, leaving the region quiet.
But she warns that an outbreak is still looming.
A 2018 study found that the Long Valley Caldera has 240 cubic miles of magma beneath the surface.
“And even if the Long Valley magma reservoir is dying, there are other pockets of magma in the area,” Montgomery-Brown said.
If the caldera erupts, it would dwarf the 1980 Mount St. Helens explosion, which sent just 0.29 cubic miles of volcanic material into the atmosphere.
In fact, the 240 cubic miles of magma stored in the valley is enough to fill 400 million Olympic-sized swimming pools.