Yellowstone is one of the most powerful supervolcanoes in the world. One blast could be enough to decimate kilometers of the national park, and extend the damage to other areas if the explosion is powerful enough. While scientists have been worried about the recent activity and the discovery of magma flowing freely underneath the surface. While it is often the one researcher’s fear the most, another one in California has been worrying due to the high intensity of earthquakes and magma moving under the surface.
Multiple supervolcanoes under surveillance: Two are in the U.S.
Not many supervolcanoes show this type of activity. These types of natural-born killers are characterized by their capacity to eject 1,000 kilometers of material into the atmosphere. Eruptions coming from these volcanoes made their last appearance thousands of years ago. Among the world’s most famous ones include Lake Toba, Lake Taupo, Aira Caldera, Yellowstone, and the Long Valley Caldera, in California.
In the United States, there’s only Long Valley Caldera and Yellowstone. While others have massive destruction power, like the one that took out Pompeii in the past and now has the famous Italian city Napoli built right next to it – or the multiple ones in Hawaii, often spewing lava. In California, things have been changing since the new readings came through the seismometers.
Yellowstone and Long Valley Caldera are active, but slower
A new study from researchers at the California Institute of Technology (Caltech) suggests the Long Valley Caldera in eastern California is slowly settling down as its magma chamber cools. The supervolcano last erupted about 100,000 years ago. An earlier blast was so powerful it covered what is now Los Angeles under nearly a kilometer of ash. Today, the caldera looks calm on the surface, but in the late 1970s it began producing swarms of earthquakes and periods of unrest that caused the ground to rise and sink.
Scientists now believe this activity doesn’t mean another catastrophic eruption is on the way. Instead, the movements are likely part of the volcano’s cooling process. According to geophysicist Zhongwen Zhan, the release of gas and fluids during cooling can still cause earthquakes and occasional small eruptions, pointing to the cluster of magnitude 6 quakes that shook the region in May 1980 as an example.
The magma moving under the surface is not enough for people to notice
To study the supervolcano’s caldera more closely, researchers used a 100-kilometer stretch of fiber optic cable as a giant seismic network. Over a year and a half, this system detected more than 2,000 seismic events, many too weak for people to notice. The data was then fed into a machine learning program, which created one of the most detailed maps yet of the volcano beneath Long Valley. Recently, scientists also had a better view of what is going on with the Yellowstone using similar technologies.
Lead author Ettore Biondi explained that this is the first time such a widespread acoustic sensor network has been able to reveal Earth’s inner structures with such precision. The images showed the caldera in striking detail, not just at shallow depths, but also as deep as 30 kilometers underground.
Long Valley Caldera is very deep: Almost reaching the center of the Earth
Researchers found the supervolcano in California has two main systems beneath it. Deep below, about 12 kilometers down, sits a huge magma chamber. Above that lies a shallower layer filled with hot water and steam. As the deeper chamber cools, it likely pushes gases and fluids upward, which could be what triggers the earthquakes.
Scientists believe the supervolcano is slowly settling, with its “beating heart” deep underground starting to quiet down. To track this process, they placed seismic sensors along a 200-kilometer fiber optic cable, about 20 kilometers deep.