A team of international researchers, including Simon Steidle from the Quaternary Research Group at the University of Innsbruck’s Department of Geology, has accurately reconstructed the evolution of groundwater in the Great Basin in the United States. This region is known for its extreme dryness. The study, published in Communications Earth & Environment, offers new insights into how climate change affects water supply and presents crucial information for sustainable groundwater resource management.
Since 2010, Christoph Spötl’s team has been studying the Devils Hole cave system in Nevada, collecting calcite deposits to reconstruct the cave’s water level development hundreds of thousands of years ago. Combining this data with a numerical groundwater model from the US Geological Survey allowed the team to draw quantitative conclusions about precipitation changes over the last 350,000 years for the entire arid region.
Groundwater data is a reflection of changes in hydroclimate in dry regions like the southwest US, where precipitation is particularly significant. According to Steidle, these findings could aid in the development of water management strategies and sustainable groundwater resource use, such as determining how much water can be utilized for agriculture.
Drought increases sensitivity
Recent data reveals that the elevation of the water table in Devils Hole is more sensitive to groundwater recharge during dry climates, with three to four times more sensitivity than during wetter climates in the past. With drought conditions likely to increase due to the ongoing climate crisis, this vulnerability underscores the importance of preserving large aquifers, the main source of freshwater in this US region. Simon Steidle warned that alterations to these resources could have significant consequences.
The study found that during interglacial warm periods, the minimum groundwater level in Devils Hole was only 1.6 meters below today’s level, indicating a decline in groundwater recharge of less than 17% compared to current conditions. In contrast, during glacial periods, the level rose to at least 9.5 meters above today’s level, indicating an increase in groundwater recharge of almost 250% compared to current conditions.
These findings have significant implications for the survival of the Devils Hole pupfish, which is only found in the water of Devils Hole and has the smallest known vertebrate habitat, about half the size of an average classroom. Even small changes in water availability due to groundwater abstraction for irrigation or climate change could have a severe impact on its survival.
Source: University of Innsbruck