Earthquake pump as an elevator for microbiomes in the accretionary prisms of subduction zones

Zhengze Li, Sylvain Barbot, & Karen Lloyd

Published September 8, 2024, SCEC Contribution #13515, 2024 SCEC Annual Meeting Poster #072

The change in atmospheric composition during the Great Oxidation Event paved the way for the most dramatic episodes of climate change in Earth’s history. Extreme glaciation periods, known as "Snowball Earth" events, challenged Proterozoic ecosystems and heavily impacted life on Earth. How did the biosphere survive these conditions? Here, we discuss how the genetic reservoir of extremophiles in the crust (intraterrestrials) may have served as Earth’s backup plan for extreme extinction events following large bolide impacts or global glaciation. We examine whether the earthquake pump that operates at subduction zones represents an effective means to resurrect buried life to the ocean floor. We explore water circulation during the poroelastic rebound that occurs in the outer wedge after megathrust earthquakes and estimate that the water flux from subduction earthquakes should exceed 1E8 Gt/Myr, corresponding to 6E26 cells/Myr. Spread around global subduction zones, the earthquake pump can liberate communities that would otherwise be sedentary in the geosphere. Subduction earthquake cycles provide a mechanism to sequester genetic material in accretionary sediment for long periods and eventually exhume live microorganisms from their crustal shelter. The earthquake pump may have contributed to the Proterozoic explosion of biodiversity that foreshadowed Ediacaran life and the Cambrian radiation.

Key Words
Evolution of life, Snowball Earth, Subduction earthquake cycles, Permeability and porosity

Citation
Li, Z., Barbot, S., & Lloyd, K. (2024, 09). Earthquake pump as an elevator for microbiomes in the accretionary prisms of subduction zones. Poster Presentation at 2024 SCEC Annual Meeting.

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