In the Eastern Sierra Nevada mountains of California, a dormant supervolcano known as the Long Valley Caldera has been dormant for an astonishing 760,000 years. However, recent signs of unrest are raising questions about its potential to unleash a catastrophic event.
With swarms of earthquakes and ground inflation at almost half an inch annually, this region has been in a state of unrest. The caldera was formed 760,000 years ago in a colossal eruption, releasing a massive 650 cubic kilometers of ash into the air, enough to bury Los Angeles under a kilometer-thick layer of sediment.
SUPERVOLCANO; DEEP BENEATH THE SURFACE
Caltech researchers have captured highly detailed underground images of the Long Valley Caldera, delving as deep as 10 kilometers into the Earth’s crust.
Despite the recent seismic activity, the study, led by Professor Zhongwen Zhan, indicates that the region is not gearing up for another supervolcanic eruption. Instead, the cooling process may release gases and liquids, potentially causing earthquakes and minor eruptions.
SUPERVOLCANO; HARDENED MAGMA CHAMBER LID
The images reveal that the volcano’s magma chamber is sealed by solidified rock, a result of cooling liquid magma. To create these images, seismic waves from earthquakes were used to determine the characteristics of materials below. Fiber optic cables and distributed acoustic sensing (DAS) technology were employed to measure over 2,000 seismic events, many imperceptible to humans, and a machine learning algorithm processed the data.
UNVEILING DEEPER MYSTERIES
This groundbreaking study is the first to create deep, high-resolution images using DAS. The team now plans to extend their research by using a 200-kilometer cable to explore even deeper into the Earth’s crust, down to around 15 to 20 kilometers, where the caldera’s magma chamber is undergoing the cooling process.
