“Devils Hole in the US offers a virtually unique opportunity to obtain long-term climate archives from calcite deposits,” emphasizes Christoph Spötl, head of the Quaternary Research Group at the Department of Geology of the University of Innsbruck. “Our many years of expertise in investigating such underground climate archives were crucial for obtaining and interpreting this extraordinary data.”
Rare climate archive tells Earth's history
In 2017, the Innsbruck expedition team succeeded in extracting a 1-meter-long drill core of calcite deposits from the deepest section of the Devils Hole II cave. Oxygen isotopes in the core document a continuous climate archive spanning 580,000 years—including the last six ice ages and the interglacial periods in between. “Our analysis shows an alternation between cool, wet ice ages and hot, dry interglacial periods,” says the study's lead author, Kathleen Wendt, now at the University of Toronto in Canada. “In the middle of some interglacial periods, there were abrupt drops in the groundwater level, which were accompanied by a significant decline in vegetation.”
The study also shows that winter rainstorms that are important for the region's water balance shifted far south during the ice ages. These shifts had a direct impact on groundwater and thus shaped living conditions in the southwestern United States in the long term. “This link between temperature, groundwater availability, and vegetation development is important for understanding future climate developments in arid regions,” explains Kathleen Wendt.
Leading role in paleoclimate research
The University of Innsbruck is one of the world's leading centers for paleoclimatology based on cave deposits. For decades, Innsbruck speleothem specialists have been regularly involved in pioneering work to access climate archives from hard-to-reach cave systems. Yuri Dublyansky, co-author of the current study, explains: “The fieldwork in Devils Hole was one of the most challenging projects we have ever been involved in. The combination of technical requirements and scientific opportunities was truly extraordinary.” Gina Moseley, cave explorer and award-winning expert at the University of Innsbruck, also emphasizes the importance of this work: “Such long-term archives are extremely rare – and therefore extremely valuable for studying natural climate change.”
In addition to the Innsbruck team, researchers from the USA, Great Britain and China were also involved in the study. The results were recently published in Nature Communications, and the study was financially supported by the Austrian Science Fund FWF, among others.
Publication: Controls on the southwest USA hydroclimate over the last six glacial-interglacial cycles. Kathleen A. Wendt, Stacy Carolin, Christo Buizert, Simon D. Steidle, R. Lawrence Edwards, Gina E. Moseley, Yuri Dublyansky, Hai Cheng, Chengfei He, Mellissa S. C. Warner & Christoph Spötl. Nature Communications 2025. DOI: 10.1038/s41467-025-64963-1