Timescales of hydrothermal scavenging in the South Pacific Ocean from 234Th, 230Th, and 228Th

•Kinetics of thorium (Th) scavenging are quantified in a SE Pacific hydrothermal plume.•Calculated adsorption and desorption rates of Th in hydrothermal plume to determine that scavenging may be irreversible.•Greater hydrothermal depletion of total 230Th relative to 228Th and 234Th.•Removal signature of 230Th is likely integrated across many scavenging events as waters flow northward above the EPR ridge axis.