The dataset comprises of analyses of two sediment cores (LC12 and LC7), extracted from Blaso, a large epishelf lake on the margin of 79 degrees N Ice Shelf, NW Greenland in July-August 2017. The data are used to constrain ice shelf dynamics over the last 8500 calibrated years before present (cal. years B.P., where present is A.D. 1950). Data for the LC7 and LC12 sediment records consist of radiocarbon (14C) chronology data.

Overlapping 2 m-long sediment cores were recovered with a UWITEC KOL ''Kolbenlot percussion piston corer to a total sediment depth of 3.74 m (LC7) and 5.24 m (LC12). Accelerator mass spectrometry (AMS) was used for radiocarbon (14C) dating.

Core LC7: 87 m water depth; 79.589 degrees N, 22.494 degrees E.

Core LC12: 90 m water depth; 79.5948 degrees N, 22.44233 degrees E.

This project was funded by the Natural Environment Research Council (NERC) through Standard Grant NE/N011228/1. We thank the Alfred Wegner Institute, and particularly Angelika Humbert and Hicham Rafiq, for their significant logistic support through the iGRIFF project. Additional support was provided from Station Nord (Jorgen Skafte), Nordland Air, Air Greenland and the Joint Arctic Command. Naalakkersuisut, Government of Greenland, provided Scientific Survey (VU-00121) and Export (046/2017) licences for this work