Lake sediment core data for the Mekong and Red River Deltas (Vietnam) and Ganges-Brahmaputra Delta (India and Bangladesh), 2022-2023

XRF Data were retrieved using high-resolution X-ray fluorescence to determine elemental composition. Magnetic susceptibility measurements were calculated using a Bartington loop sensor to determine lithological changes in the sediment core. Chronology data include 210Pb, 226Ra, 137CS, 241AM through direct gamma assay and 14C by mass spectrometry. Grain-size analyses were conducted using high performance laser diffraction particle analysis. Sedimentary pigments were retrieved using high performance liquid chromatography separation of pigments produced by algal groups. Total inorganic carbon (TIC) was determined using acid to dissolve carbonates, total organic carbon (TOC) was determined by burning off all carbon at 1200 C. Total organic carbon is calculated using the difference between total carbon and total inorganic carbon. Stable isotopes were measured using continuous flow isotope ratio mass spectrometry for carbon and nitrogen. Water chemistry and site data include contextual information (broader area, latitude and longitude, pond water depth, Secchi depth, core length and whether cores were obtained whole or extruded, as well as actual conductivity, specific conductivity, salinity, TDS, pH, ORP, RDO and temperature using an In-Situ AQUA TROLL 500.

Dates of core collection include 15-07-2022 to 19-07-2022 for the Red River Delta, 14-05-2023 to 17-05-2023 for the Mekong River Delta, 27-02-2022, 03-03-2022 to 05-03-2022, 07-03-2022 to 08-03-2022 for the Indian GBM, and 03-11-2022 to 07-11-2022 for the Bangladeshi GBM. Not all sites have had every analysis completed based on available time, core quality, and/or issues with additional funding or equipment. However, all analyses are expected to be completed within the next year or two. Bangladesh currently has the most complete dataset, followed by the Red River Delta sites and India.