The average person’s idea of how climate change might someday plunge the world into a series of post-apocalyptic, fresh-water resource wars probably focuses on the simple equation that rising temperatures equal more drought. But the reality is a bit more unusual, according to a recent report by the United Nations’ World Meteorological Organization.
Think of the world’s mountain glaciers, like those now melting in the Himalayas, as their own kind of freshwater savings account, keeping potable water on literal ice for judicious, naturally timed releases into nearby rivers and underground aquifers. Now, geologists with the Utah Geological Survey, the University of Utah, and other institutions are busy working to locate and catalogue their state’s hidden reserves of ice, frozen into so-called “rock glacier” formations often concealed from aerial surveys. The hope, as the state surveyor’s Brigham Young University collaborators described it, is to better “inform future water management.”
Using a sensitive gravimeter, a gravity-measuring device which helps differentiate between underground deposits of rock and ice, the survey team reports that it has documented 70 frozen deposits hidden under debris near the summit of Utah’s Mount Timpanogos outside Provo. Timpanogos’ rock glaciers up near the mountain’s 7,000-foot-tall (2,100-meter-tall) peak, according to one of the team’s two new studies, currently contains a total ice volume equivalent to “roughly 600 Olympic-sized swimming pools,” or about 396 million gallons.
“There’s a lot of ice that’s hidden in Utah’s mountains,” University of Utah glaciology professor Leif Anderson, a coauthor on both studies, said in a statement. “When we are high in the mountains and walking across loose rocks or rubble, you don’t realize there could be 120 feet of ice buried beneath your feet.”
Cold comfort
Based on estimates by Utah’s Department of Natural Resources, meltwater from Utah mountains like Timpanogos provide over 95% of the state’s freshwater supplies. And the 232 gravity measurements made by Anderson’s team while traversing atop Timpanogos helped finally figure out where some of that water actually comes from.
“Timpanogos Rock Glacier is surprisingly ice rich,” Anderson’s research collaborator Bronson Cvijanovich, who studied geophysics at the University of Utah, said in a statement. “It is 83% ice and 17% loose rock.”
Their measurements were made off the principle that changes in mass along various locations along the rock glacier (due to the differing densities of ice, which floats, and rock, which doesn’t) are detectable via very subtle changes in the Earth’s gravitation pull. Based on their gravimetric survey of Timpanogos, the team estimated that its hidden glacial ice has an average thickness around 61.7 feet (18.8 meters) deep.
“Rock glaciers flow downhill just like a glacier or river, but the important distinction here is that the thick carapace of loose rock actually protects and hides the ice, making these climate-resilient water storage sites that may still be adding frozen water,” according to Cvijanovich, the lead author of one of studies and now a technician for a local geothermal energy company.
“From a water resource standpoint, it is really important, especially in a warm and arid state like Utah,” Cvijanovich explained.
Ice ages
The second new study produced by Anderson and his colleagues developed new modeling tools to measure how much of the Timpanogos rock glacier is ancient permafrost dating back roughly 20,000 years to the last Ice Age, technically known as the “Last Glacial Maximum.” Their calculations pooled together data from snow probes planted in May 2024, as well as satellite data measuring the light reflectance of visible snow and climate reports from local meteorological stations.
Anderson expressed some optimism over the team’s findings, which indicated that ice deposits have managed to occasionally grow while protected from the Sun’s rays within this mountain’s rock glaciers—a reality that might hold lessons for protecting critical glaciers in the near future.
“This is not just ice that’s left from the time of Lake Bonneville and mammoths,” Anderson said. “We don’t yet know which rock glaciers are still adding ice today outside of a few dozen under active research. […] But Timpanogos rock glacier is still adding ice today!”
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