By Margherita Bassi Published January 14, 2025 | Comments (0) | A large-volume spring in young volcanic rocks in the Cascades. Benjamin Nash While studying the landscape of Oregons Cascade Range, also known as the Cascades, a team of scientists discovered that a region of subsurface water is far larger than previously thoughtand may even be a record holder. The discovery is both a blessing and a potential curse, serving as a vital water source while also posing a volcanic hazard. Researchers from the University of Oregon and other institutions have identified an aquifera layer of water-saturated rock or sedimentbeneath volcanic rocks at the crest of the central Oregon Cascades. Its volume of at least 19.43 cubic miles (81 cubic kilometers) is much larger than scientists previously estimated. Thats more than half the volume of Lake Tahoe. The discovery, detailed in a study published on January 13 in the journal PNAS, could reshape understanding of the regions water supply and aid geologists in evaluating potential volcanic hazards. It is a continental-size lake stored in the rocks at the top of the mountains, like a big water tower, said Leif Karlstrom of the University of Oregon, who led the study, in a university statement. That there are similar large volcanic aquifers north of the Columbia Gorge and near Mount Shasta likely make the Cascade Range the largest aquifer of its kind in the world. This region has been handed a geological gift, but we really are only beginning to understand it. Oregons Cascade Range mountains were built by volcanoes and are typically divided into two regions: the western Cascades, with older river-carved slopes and valleys, and the high Cascades, featuring a younger, flatter landscape with lakes and volcanic topography, including lava flows. Scientists can study the transition zone between these two contrasting regions to analyze how volcanoes have changed the mountain ranges landscape.We initially set out to better understand how the Cascade landscape has evolved over time, and how water moves through it, said Gordon Grant, a geologist with the Forest Service who also participated in the study. But in conducting this basic research, we discovered important things that people care about: the incredible volume of water in active storage in the Cascades and also how the movement of water and the hazards posed by volcanoes are linked together.In other words, the discovery of the aquifers size is good andpotentiallybad. The Cascades provide a substantial amount of drinking water for the people of Oregonmost of the city of Eugenes potable water, for example, comes from the McKenzie River. At the same time, volcanic eruptions with large quantities of water tend to be more explosive, and as a consequence, more dangerous. The team of researchers was able to map the extent of the aquifer by relying on previous field work in the 1980s and 1990s during which scientists had drilled holes to measure temperatures deep into the earth. While rocks usually get hotter the deeper they are, the presence of underground water can lower temperatures. The team reused the holes to, once again, measure rock temperatures, and consequently infer the expanse of the aquifer from these temperature variations.The inferred volume greatly exceeded earlier estimates. Given that the team only used previously drilled holes, which might have missed parts of the aquifer, the volume could be on the conservative side of its true expanse. It may actually be even bigger. While the aquifers underestimated size is an exciting discovery, the researchers also warned that it remains a limited resource that could be affected by changes in precipitation of snow and rain projected for the region.This region has been handed a geological gift, but we really are only beginning to understand it, Grant said. If we dont have any snow, or if we have a run of bad winters where we dont get any rain, whats that going to mean? Those are the key questions were now having to focus on. It remains to be seen how the the state of Oregon will handle the complex intersection between water resources and volcanic hazards presented by this new discovery.Daily NewsletterYou May Also Like By Lucas Ropek Published October 29, 2024 By Adam Kovac Published October 26, 2024 By Adam Kovac Published October 2, 2024 By Isaac Schultz Published September 3, 2024 By Ed Cara Published July 12, 2024 By Matthew Gault Published July 10, 2024