State shifts in the deep Critical Zone drive landscape evolution in volcanic terrains

• DOI: 10.1073/pnas.2415155122
• Publication Date: 2025-01-13T20:06:47Z
• Authors: Leif Karlstrom; Nathaniel Klema; Gordon E. Grant; Carol Finn; Pamela L. Sullivan; Sarah Cooley; Alex Simpson; Becky Fasth; Katharine Cashman; Ken Ferrier; Lyndsay Ball; Daniele McKay

Volcanic provinces are among the most active but least well understood landscapes on Earth. Here, we show that central Cascade arc, USA, exhibits systematic spatial covariation of topography and hydrology linked to aging volcanic bedrock, suggesting controls landscape evolution. At crest, a locus Quaternary volcanism, water circulates deeply through upper [Formula: see text]1 km crust transitions shallow dominantly horizontal flow as rocks age away from arc front. We argue this pattern reflects temporal state shift in deep Critical Zone. Chemical weathering at depth, surface particulate deposition, tectonic forcing drive an initial with minimal topographic dissection, large vertical hydraulic conductivity, abundant lakes, muted hydrographs toward fluvial small few flashy hydrographs. This has major implications for regional resources. Drill hole temperature profiles imply text] km[Formula: groundwater currently stored Range discharge variability strong function bedrock age. Deeply circulating also impacts Holocene High Cascades eruptions reflect explosive magma-water interactions increase hazard potential. propose Zone drives evolution wet climates represents framework understanding interconnected solid earth dynamics climate these terrains.