Thorium-234 as a tracer for deep-sea mining sediment plume deposition.

ABSTRACT: Deep-sea mining for polymetallic nodules is currently exploratory, but commercial-scale operations require indicators of environmental change to support regulatory thresholds and inform adaptive management. In the Clarion-Clipperton Zone, where background sedimentation rates are low, seafloor imagery has validated mining plume deposition but cannot resolve repeated sedimentation as nodules become buried. Thorium-234 (²³⁴Th), a naturally occurring radionuclide with a 24.1-day half-life and strong particle reactivity, serves as a high-resolution geochemical tracer. Here we apply sedimentary ²³⁴Th to identify the spatial extent of plume deposition following the NORI-D mining test. Excess ²³⁴Th (²³⁴Th_xs) activity was low at baseline but el

SUBMITTER: O'Malley BJ 

PROVIDER: S-EPMC12660702 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature