Lake Mead, which has been in the headlines for several months for having seen dead bodies rise to its surface, is in the headlines again. This time, rocks were discovered. They could eventually become dangerous.
Lake Mead has not finished revealing its secrets. While the body of water that crosses several states between Nevada and Arizona has seen its level drop dramatically due to an intense drought, five bodies have risen to the surface in recent months. Shipwrecks have also been seen. This time, it is particular rocks that have been exposed due to the lack of water. A study by the University of Nevada published by the Geological Society of the United States explains that these rocks had not been visible since the 1930s, the year the lake dam was built.
It is above all the incredible history that they contain that interests the experts. In fact, they would contain volcanic ash dating back to prehistoric times (their date is actually between 12 million years and 32,000 years). Eugene Smith, a professor emeritus at the University of Nevada, told KSL News radio that the study provides insight into the West’s geographic past. “It’s very exciting,” he commented, noting that the study may have been done because of the low water level in the lake.
A health risk
The University of Nevada team reports that the different layers of ash help determine how often the Las Vegas area has been hit by these ash clouds over time. The objective is then to be able to prepare for future volcanic activities in more distant regions. The study identified four possible sources of ash from surrounding states, including Yellowstone National Park and the Ancestral Falls that stretch from northern California to British Columbia, Canada. Areas near the Las Vegas Valley have also been included in the list, such as the volcanic field of southwestern Nevada and the Walker Lane volcanoes in southern California.
But these ashes could eventually have a dangerous impact on the region. And for good reason, despite the millions or thousands of years that separate them from our century, they could one day hit the valley hard, causing health problems, power outages, or road transportation. “Even a few millimeters of ash, when wet, are incredibly heavy and can destroy power and telecommunications lines,” writes Eugene Smith in his study.
He adds that volcanic ash, even in moderate amounts, can travel thousands of kilometers, covering entire areas with heavy material. If these ashes are inhaled, the particles inside, including sharp glass grains, can also cause chronic lung problems. “Ash is rapidly reformed by wind and water,” says Eugene Smith. “Although the Las Vegas Valley is currently a long way from any active volcanoes, we will see ash from these volcanoes fall over southern Nevada in the future.” Volcanic ash can contain volcanic glass, debris, and crystals from the magma chamber that fuels the eruption.