This dataset contains the position and depth of four spatially-extensive Internal Reflecting Horizons (or IRHs) traced on the British Antarctic Survey''s PASIN system and NASA Operation IceBridge''s MCoRDS2 system across the Pine Island Glacier catchment. Using the WAIS Divide ice-core chronology and a 1-D steady-state model, we assign ages to our four IRHs: (R1) 2.31-2.92 ka, (R2) 4.72 +/- 0.28 ka, (R3) 6.94 +/- 0.31 ka, and (R4) 16.50 +/- 0.79 ka. This project was funded by the UK Natural Environment Research Council Grant NE/L002558/1

This dataset contains the position and depth (ice thickness) of three spatially-extensive Internal Reflecting Horizons (IRHs) mapped from ice-penetrating radar data acquired with the British Antarctic Survey''s PASIN and PASIN2 ice radar systems across central East Antarctica. The dataset extends geographically from Dome A to South Pole. Using previous dated IRHs from Winter et al (2019), an independent validation of IRH ages from the South Pole ice-core chronology and a 1-D steady-state model, we assigned ages to our three IRHs: (H1) 38.5 +/- 2.2 ka, (H2) 90.4 +/- 3.57, and (H3) 161.9 +/- 6.76 ka. This study was motivated by the AntArchitecture Action Group of the Scientific Committee for Antarctic Research (SCAR). The project was supported by the National Environmental Research Council (NERC)-funded ONE Planet Doctoral Training Partnership (NE/S007512/1), hosted jointly by Newcastle and Northumbria Universities. The authors thank the BAS science and logistics teams for acquiring both the AGAP PASIN and PolarGAP PASIN2 data which is fully available on the Polar Airborne Geophysics Data Portal of the UK Polar Data Center (https://www.bas.ac.uk/project/nagdp/). BedMachine (version 2) data are available at https://doi.org/10.5067/E1QL9HFQ7A8M.