Is California's Supervolcano About to Erupt?

 

By Rameen

Here's What Science Says:

 

California's supervolcano, the Long Valley Caldera, is stirring. Recent activity suggests potential signs of life, sparking concerns about its potential to erupt. But what does the science say?

 

The Quakes: A Symptom of Activity

 

Researchers at the California Institute of Technology (Caltech) have detected over 2,000 earthquakes in the Long Valley Caldera in recent times. Such seismic activity in a supervolcano is enough to raise eyebrows. The team, keen to understand if these tremors heralded an impending catastrophic eruption, delved deep into the heart of the caldera.

 

Understanding the Underground

 

Caltech scientists embarked on a detailed investigation, capturing underground images of the caldera. The primary aim was to determine whether these tremors indicated an increasing risk of eruption or if they signaled the caldera settling down.

 

Their findings were reassuring. The recent seismic activity, they discovered, is due to the release of fluids and gases as the region cools and stabilizes. Zhongwen Zhan, the study's lead author, clarified, "We don't believe the region is on the brink of another supervolcanic eruption. However, as it cools, it might release gases and fluids, which could cause earthquakes and minor eruptions."

The Long Valley Caldera is no stranger to massive eruptions. About 767,000 years ago, it experienced a colossal explosion, ejecting 140 miles of volcanic material into the atmosphere, leaving a mark on the landscape. For context, in May 1980, the region saw four earthquakes, each of magnitude 6.

 

Modern Techniques: Peeking Below the Surface

 

To better understand the caldera's activity, Zhan's team employed distributed acoustic sensing (DAS). They strategically placed seismometers across the Eastern Sierra region and laid out cables spanning 62 miles of the caldera. Over 18 months, they detected more than 2,000 seismic events, the majority of which were imperceptible to humans.

 

Utilizing machine learning, the team processed these measurements to generate a comprehensive image, pinpointing each quake's location.

 

Expert Opinions

 

Emily Montgomery-Brown, a Long Valley Caldera specialist not affiliated with the study, noted that earthquake swarms began in 2011. By 2020, the region witnessed ground deformation, with the land rising and tremors dissipating, leading to a quieter period. However, Montgomery-Brown cautions that an eruption is still a possibility.

 

The Magma Reservoir: A Reservoir of Power

 

A 2018 study illuminated the caldera's staggering magma storage: 240 cubic miles, enough to fill 400 million Olympic swimming pools. In comparison, the 1980 Mount St Helens eruption spewed a mere 0.29 cubic miles of volcanic material.

 

Montgomery-Brown added, "Even if the Long Valley magma reservoir is dormant, there are other magma pockets in the vicinity."

Are There Any Warning Signs?

Volcanoes are complex geological systems, and predicting their activity with absolute certainty is challenging. However, scientists use a variety of signs and monitoring techniques to assess the likelihood of an eruption. Here are some scientific signs that a volcano may become active or erupt soon:

 

Seismic Activity: Increased earthquake activity (seismicity) is often the most reliable indicator of an impending eruption. As magma rises towards the surface, it can fracture surrounding rock, causing small earthquakes.

 

Ground Deformation: The movement or intrusion of magma can cause the ground to bulge or deform. Using instruments like tiltmeters and GPS, scientists can measure even tiny changes in the volcano's shape.

 

Gas Emissions: As magma nears the surface, it releases gases. Monitoring stations can detect increased levels of volcanic gases like sulfur dioxide (SO2), carbon dioxide (CO2), and water vapor.

 

Temperature Changes: The temperature at the volcano's surface can increase due to the approaching magma. This can be observed directly or with thermal imaging.

 

Changes in Volcanic Lakes: Some volcanoes have lakes in their craters. Changes in the water's temperature, color, or chemistry can signal volcanic activity.

 

Phreatic Eruptions: These are small steam-driven explosions caused when groundwater is heated by magma. They can be precursors to larger eruptions.

 

Audible Sounds: As magma moves or gases escape, they can create rumbling sounds or a roaring noise, which can sometimes be heard from the volcano.

 

Visual Changes: New vents or cracks may appear, or existing ones may become more active. There might also be an increase in the emission of steam or ash.

 

Historical Patterns: Some volcanoes have patterns of eruptions. By studying a volcano's eruption history, scientists can sometimes predict when it might erupt again.

 

Animal Behavior: While not strictly scientific, there are anecdotal reports of animals acting unusually before eruptions, possibly because they sense the increased seismic activity or changes in gas emissions.

 

It's essential to understand that while these signs can indicate increased volcanic activity, they don't guarantee an eruption. Some volcanoes show signs of activity for years without erupting, while others can become active with little warning. Scientists use a combination of these signs, continuous monitoring, and advanced models to assess and forecast volcanic activity.

 SO, 

While the Long Valley Caldera is showing signs of activity, current scientific data suggests that a supervolcanic eruption is not imminent. Nevertheless, the sheer volume of magma beneath emphasizes the need for continuous monitoring and understanding of this geological marvel. After all, nature often surprises us, and it's always best to be prepared.