Tectonic pump as an upward elevator for microbes in the accretionary prism of subduction zones

Zhengze Li, Sylvain D. Barbot, & Karen Lloyd

Submitted September 7, 2025, SCEC Contribution #14424, 2025 SCEC Annual Meeting Poster #TBD

Deep marine sediments host one of Earth’s largest microbial biospheres, however extreme energetic limitation limits cell proliferation in the vast majority of marine sediments and low advection severely restricts dispersal of microbial cells. How microbes adapt to this multi-thousand year or longer non-growth state is currently unknown. Here, we investigate whether subduction zone slip events may drive microbial migration and reactivation. By analyzing water circulation in the outer wedges following slip events, we estimate that subduction-related water flux exceeds 1E6 Gt/Myr, capable of transporting approximately 1E25 cells/Myr globally. These processes can return deeply-buried microbial communities to the surface where resources are sufficient for them to pass adaptive genetic mutations to the next generation. We suggest this tectonic pump mechanism may shape microbial ecosystems, and, in turn, influence biogeochemical cycles. Our study quantifies the intricate link between Earth's physical processes and its deep biosphere.

Key Words
Seismic cycle; Fluid migration; Earthquake–biosphere coupling; Episodic tremor and slip (ETS)

Citation
Li, Z., Barbot, S. D., & Lloyd, K. (2025, 09). Tectonic pump as an upward elevator for microbes in the accretionary prism of subduction zones. Poster Presentation at 2025 SCEC Annual Meeting.

Related Projects & Working Groups
Stress and Deformation Over Time (SDOT)