EastGRIP ice core mercury record over the Holecene: From the ice accumulation record to atmospheric depositional history

Mercury is a contaminant of global concern, but anthropogenic impact on preindustrial mercury cycling in remote locations remained poorly constrained. Here we report a high-resolution record of the mercury concentration and accumulation flux over the Holocene, established by the analysis of the recently retrieved EastGRIP ice core from Greenland. We show that the Holocene ice core mercury record was shaped by a combination of volcanic eruptions, climate excursions, and in recent millennia anthropogenic activity. Our result suggests that human activity started to impinge on Greenlandic mercury cycling since at least 2000 years ago, much earlier than previously thought. We will also discuss the challenges encountered in establishing atmospheric mercury deposition history from the ice core record due to uncertainties associated with potential changes in post-depositional processes over the Holocene.