1932

Abstract

The canonical water cycle assumes that all water entering the subsurface to form groundwater eventually reenters the surface water cycle by discharge to lakes, streams, and oceans. Recent discoveries in groundwater dating have challenged that understanding. Here we introduce a new conceptual framework that includes the large volume of water that is estimated to account for 30–46% of the planet's groundwater but that is not yet incorporated in the traditional water cycle. This immense hidden hydrogeosphere has been overlooked to date largely because it is stored deeper in the crust, on long timescales ranging from tens of thousands to more than one billion years. Here we demonstrate why understanding of this deep, old groundwater is critical to society's energy, resource, and climate challenges as the deep hydrogeosphere is an important target for exploration for new resources of helium, hydrogen, and other elements critical to the green energy transition; is under investigation for geologic repositories for nuclear waste and for carbon sequestration; and is the biome for a deep subsurface biosphere estimated to account for a significant proportion of Earth's biomass.

  • ▪  We provide a new conceptual framework for the hidden hydrogeosphere, the 30–46% of groundwater previously unrecognized in canonical water cycles.
  • ▪  Geochemico-statistical modeling groundwater age distributions allows deconvolution of timing, rates, and magnitudes of key crustal processes.
  • ▪  Understanding and modeling this deep, old groundwater is critical to addressing society's energy, resource, and climate challenges.


Expected final online publication date for the , Volume 52 is May 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Loading

Article metrics loading...

/content/journals/10.1146/annurev-earth-040722-102252
2024-01-25
2024-04-16
Loading full text...

Full text loading...

/content/journals/10.1146/annurev-earth-040722-102252
Loading

Supplemental Material

Supplemental Material

  • Article Type: Review Article
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error