[Rockhounds] California Supervolcano: Caltech’s “Chilling” Discovery in Long Valley Caldera

[Kreigh Tomaszewski]

Caltech researchers used advanced imaging techniques to investigate
increased seismic activity in California’s Long Valley Caldera, a dormant
supervolcano.

Since the 1980s, researchers have observed significant periods of unrest in
a region of California’s Eastern Sierra Nevada mountains characterized by
swarms of earthquakes as well as the ground inflating and rising by almost
half an inch per year during these periods. The activity is concerning
because the area, called the Long Valley Caldera, sits atop a massive
dormant supervolcano
<https://www.usgs.gov/faqs/what-a-supervolcano-what-a-supereruption>. Seven
hundred and sixty thousand years ago, the Long Valley Caldera was formed in
a violent eruption that sent 650 cubic kilometers of ash into the air—a
volume that could cover the entire Los Angeles area in a layer of sediment
1 kilometer thick.
Groundbreaking Imaging Reveals Insights

What is behind the increased activity in the last few decades? Could it be
that the area is preparing to erupt again? Or could the uptick in activity
actually be a sign that the risk of a massive eruption is decreasing?

To answer these questions, Caltech researchers have created the most
detailed underground images to date of the Long Valley Caldera, reaching
depths up to 10 kilometers within the Earth’s crust. These high-resolution
images reveal the structure of the earth beneath the caldera and show that
the recent seismic activity is a result of fluids and gases being released
as the area cools off and settles down.

https://scitechdaily.com/california-supervolcano-caltechs-chilling-discovery-in-long-valley-caldera/