RECAP (The REnland ice CAP project) 2015
Principal investigator: Bo M. Vinther, Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen.
Location: Renland ice cap, vicinity of 71 18’ 18’’ N; 26 43’ 24’’ W, 2340 m a.s.l.
The Renland ice cap is situated in Eastern Greenland on a high elevation plateau on the Renland peninsula in the Scoresbysund fjord (figure 1). Climatic conditions on the Renland ice cap are strongly influenced by the varying Arctic sea ice export along Greenland’s east coast. An ice core from the Renland ice cap is thus perfectly suited for obtaining information on Eastern Greenland climatic conditions including the export of sea ice from the Arctic Ocean for the past 100,000 years. The RECAP ice core drilled to bedrock will be the backbone of a coordinated science program between Denmark, the U.S., Germany and Italy. The shallowness of the Renland ice cap furthermore assures that it does not have a brittle ice zone in the Holocene ice like the Greenland ice sheet. The RECAP ice core can therefore yield the first continuous Holocene profiles of gasses and chemical impurities extracted from Greenland.
The Renland ice cap is constrained by the surrounding topography and its eastern plateau reaches an elevation of 2340m at its summit, where the thickness of the ice cap is almost 400m and the accumulation rate approximately 0.5m of ice equivalent precipitation per year. Brittle ice, that is very detrimental to ice core quality, forms at depths below 600m, hence in contrast to the main Greenland ice sheet, the Renland ice cap contains no brittle ice zone. An ice core from Renland will therefore also yield the first continuous Holocene profiles of gasses and chemical impurities from Greenland.
Given the unique location and properties of the Renland ice cap, the RECAP core will provide data with direct bearing on the following high-priority science questions:
- How did the East Greenland and thus Arctic sea-ice conditions evolve during the Holocene and the Glacial and how did conditions and variability compare to the present downturn in sea ice?
- How did the atmospheric composition, including pole-to-pole gradients in trace gas contents, change during the entire Holocene?
- What is the East Greenland signature of the abrupt climate shifts seen during the last Glacial?
- Has the Renland ice cap always had the same shape and size, so the climate record from a Renland ice core can be assumed to stem from snow deposition on a site with unchanged elevation, yielding a Greenland climate record at fixed elevation?
These science questions are directly influencing how the scientific community will interpret the present decline in Arctic sea-ice; our future understanding of the dynamics of the climate system; our interpretation of Human and natural influences on the Earths atmospheric composition; and our future interpretation of the ice cores from the main Greenland ice sheet. To address these, as well as numerous other science questions, we propose to drill the RECAP core through the Renland ice cap down to bedrock. Drill site location will be near the dome of the ice cap (exact coordinates to be determined using U.S. radar equipment). The core will be drilled with the modern well-proven Copenhagen intermediate drill system, capable of drilling high quality 4 inch diameter cores in liquid-filled boreholes. Furthemore a firn-gas project will be carried out using a U.S. firn gas sampling system and the Copenhagen shallow-drilling system (3 inch cores).
Scientific plan for RECAP 2015
Late April to early May: Radar measurements with CRESIS surface radar, establish skiway (4 crew).
Early May to end of May: Establish main camp, deep drilling, firn gas project (11 crew).
Beginning of June to late June: Deep drilling, rapid access test, take down camp (11 crew).