Dataset: Particulate Th-234 collected using large volume McLane pumps (LVPs) as part of the EAGER chief scientist training cruise (KM1910) at Station ALOHA, subtropical North Pacific gyre in June 2019

In-situ particulate material was collected using McLane pumps. All thorium data were decay-corrected back to mid-pumping times. See Pike et al., 2005 and Clevenger et al., 2021 for detailed methods and counting techniques.

>51 micrometer (µm) Th-234 (LSF, large particulate Thorium): The entire 142 millimeter (mm) mesh screen was rinsed onto a 25 mm silver filter and dried in a low temperature oven before beta counting. The mean volume pumped through the 142 mm mesh screens was ~640 liters (L).

1-51 micrometer (µm) Th-234 (SSF, small particulate Thorium): Whole 142 mm QMAs, located below the mesh screen in the filter head housing, were dried in a low temperature oven. A 25 mm subsample was taken from this 142 mm filter for beta counting for Th-234.