Overview
- Eric Boyd and colleagues report in PNAS Nexus that a 2021 swarm of small earthquakes beneath the Yellowstone Plateau altered an aquifer’s chemistry and biology.
- Fluid samples taken five times in 2021 from a nearly 100-meter borehole on the lake’s western shore recorded rises in hydrogen, sulfide, and dissolved organic carbon after the shaking.
- Planktonic cell concentrations increased and the microbial community composition shifted following the chemical changes observed in the borehole fluids.
- The authors attribute the transient changes to quake-driven fracturing that exposes reactive rock, releases trapped fluids, and redirects subsurface flow paths, reshaping available energy sources.
- The team suggests similar dynamics could occur in other seismically active aquifers and may have implications for subsurface habitability on rocky planets such as Mars.