12-Million-Year-Old Volcanic Rock Emerges From Lake Mead Amid Water Crisis

by Lauren Boisvert
(Photo by David McNew/Getty Images)

Lake Mead is receding to dangerously low levels, and many shocking things have surfaced since the water levels started dropping during the summer mega-drought. Things like old boats, sunken warships, and even human remains. Now, researchers have found rocks laced with volcanic ash from 12 million years ago.

The low water levels are exposing rocks that haven’t been seen since the Hoover Dam was built. As of September, the reservoir is at around 27% capacity, which is barely 1,045 above sea level. As for the volcanic rocks, researchers at the University of Nevada in Las Vegas studied the find. They found sediment from volcanoes in Idaho, Wyoming, and California, according to a report from CNN.

“We knew that these ash units existed, but we were surprised to find so many as the Lake Mead water level lowered,” said an emeritus professor of geology at UNLV, Eugene Smith. These sediment levels haven’t been exposed to air in nearly 100 years, and scientists are chomping at the bit to study them.

On rocks that were previously underwater, Smith’s research team found swirling lines of volcanic ash. They took samples to pinpoint the date and location, but it wasn’t from one single eruption. Instead, it was from many different eruptions across what are now three different states.

There was evidence of eruptions from the Snake River Plain-Yellowstone area. This is a section of inactive volcanoes that stretches from Idaho to Yellowstone National Park. There was also evidence from eastern California. Additionally, some eruptions only occurred 32,000 years ago.

How Studying Lake Mead Volcanic Rocks Can Provide Insight Into the Future

According to Jake Lowenstern, a research geologist with the US Geological Survey, studying these rocks can give researchers valuable insight into the future of the planet. The collection of volcanic ash in Lake Mead is “important in allowing us to reconstruct the geologic history of the region, and to understand the frequency of large volcanic eruptions and their impact on the Southwest,” said Lowenstern.

This study is crucial for future volcanic events on the planet. For one, because volcanic ash can travel hundreds of miles across different parts of the world. “These ashfall events can disrupt transportation and supply networks, close airports, and potentially be a health hazard,” said Smith. “It’s important for local governments to develop plans to deal with this sort of event, like they have for earthquakes and flooding.”

According to Smith, even far-away volcanoes could potentially cause problems here. It’s important to have plans in place for events like that, and to study the effects of “present and future climate change.”

“Studying the past is the key to understanding the future,” Smith explained. “By understanding past volcanic events, we can better understand how a future event may affect a large metropolitan area. We can also develop plans to deal with a volcanic eruption when one occurs in the future.”