Elevated Grand Canyon groundwater recharge during the warm Early Holocene
Lachniet, M.S.; Du, X.; Dee, S.G.; Asmerom, Y.; Polyak, V.J.; Tobin, B.W. (2023). Elevated Grand Canyon groundwater recharge during the warm Early Holocene. Nature Geoscience 16(10): 915-921. https://dx.doi.org/10.1038/s41561-023-01272-6
In: Nature Geoscience. Nature Publishing Group: London. ISSN 1752-0894; e-ISSN 1752-0908, meer
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| Auteurs | | Top |
- Lachniet, M.S.
- Du, X.
- Dee, S.G.
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- Asmerom, Y.
- Polyak, V.J.
- Tobin, B.W.
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| Abstract |
Summer rainfall is an important contributor to water budgets in western North American deserts, where intense rainfall sustains ecosystems while also causing flash floods and damaging erosion. A better understanding of Grand Canyon palaeoclimate and the long-term history of the summer monsoon from summer-sensitive palaeoclimate records will improve our ability to project future hydroclimatic changes under warmer conditions. Here we show multi-proxy evidence for an intensification of the Early Holocene (11,700–8,200 years ago) hydrological cycle linked to a stronger and expanded summer North American Monsoon from calcite oxygen and uranium isotopes in a uranium-series precisely dated stalagmite from a Grand Canyon cave. Our results suggest that subsurface infiltration was greater in the Early Holocene than today at Grand Canyon. A data–model comparison with an isotope-enabled climate model suggests that enhanced infiltration was due to an Early Holocene monsoon intensification associated with rising atmospheric temperature. Projections of a future increase in precipitation intensity or more frequent and expanded North American monsoon rain events may paradoxically result in increased subsurface infiltration at Grand Canyon and other high-altitude plateaus, even within the context of western North American aridification in a hotter climate. |
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