Ice-wedge evidence of Holocene winter warming in the Canadian Arctic ...

• Main Authors: Porter, Trevor, Holland, Kira, Buchanan, Casey, Froese, Duane, Kokelj, Steven
• Format: Dataset
• Language: unknown
• Published: Canadian Cryospheric Information Network 2021
• Subjects: Climate change; Richards Island
• Online Access: https://dx.doi.org/10.21963/13163; https://www.polardata.ca/pdcsearch/?doi_id=13163

In this study, we sampled lateral cross-sections of four relict ice wedges from retrogressive thaw slump and coastal bluf exposures on Hooper Island, Pelly Island, Richards Island and the mainland coast near Tuktoyaktuk. Ice blocks capturing the entire growth sequences of the ice wedges (i.e., ice wedge center to ice-sediment contact) were collected by chainsaw and kept frozen in field coolers, and later sub-sampled at high-resolution in a cold lab. The ice wedges were sub-sampled at 1-1.5 cm horizontal resolution, integrating ~1-3 ice veins per sample on average. We analysed the stable hydrogen- and oxygen-isotope ratios (δ2H and δ18O) of each sample (N = 803). The age of the ice was estimated by AMS-DO14C dating of 6 to 10 samples per ice wedge, evenly distributed across each wedge to capture the full range of ages. A composite δ18O record spanning the period 7,400-600 cal yr BP was also constructed using the dated samples only (N = 36). The all-sample co-isotope (δ2H-δ18O) data are defined by a regression ... : The ice wedge oxygen isotope data were collected to better understand long-term changes in the mean winter climate of the study region. Currently there are few data constraining changes in mean winter climate over the Holocene (last 11,700 years), but a relative abundance of data on the warm-summer season. The lack of winter data limits our ability to understand the sensitivity of the winter season to climate forcings such as insolation and greenhouse gas concentration, which is needed to better predict future climate change in the Arctic. These data contribute to a more holistic understanding of the Arctic climate system. ...