New Estimate Makes Groundwater Earth’s Largest Water Reservoir on Land
Source: New Estimate Makes Groundwater – Not Ice Sheets – Earth’s Largest Water Reservoir on Land – Leak Herald Hot springs, which can source deep groundwater, are one of the places on the surface where there is evidence of rainwater circulating to depths of two kilometers and deeper. In the states, the top places for finding groundwater are Mississippi, Kansas, Arkansas, Nebraska, and South Dakota. New research doubles volume of salty water two to 10 kilometers beneath the surface that could store waste fluids, sequester carbon, and direct our search for extraterrestrial life. New research more than doubles the estimated volume of ancient, salty groundwater stored deep within Earth’s crust. Around 24 million cubic kilometers (5.8 cubic miles) of groundwater reside within the top two kilometers (1.2 miles) of Earth’s crust. This shallow groundwater is what we use for drinking and irrigation, and it’s mostly freshwater. But below that are vast reservoirs of brine, some of it hundreds of millions to more than a billion years old, locked away in the rocks. The question was: How much is there? A new study estimates there are around 20 million cubic kilometers of deep groundwater, or enough to fill around 4,800 Grand Canyons. Combined with previous estimates of shallower groundwater, the new research finds underground water is the largest reservoir of water on land, measuring 44 million cubic kilometers and surpassing the volume of Earth’s ice sheets. “This estimate expands our conceptual and practical understanding of the amount of water that Earth holds, and it adds a whole different dimension to the hydrologic cycle,” said Grant Ferguson, a hydrogeologist at the University of Saskatchewan who was lead author of the new study in the AGU journal Geophysical Research Letters, which publishes high-impact, short-format reports with immediate implications spanning all Earth and space sciences. [...]