Chemical compositions of solid particles present in the Greenland NEEM ice core over the last 110,000 years ...

• Main Authors: Steffensen, Jørgen Peder, Fischer, Hubertus, Fukui, Manabu, Svensson, Anders, Oyabu, Ikumi, Hansson, Margareta, Iizuka, Yoshinori, Gfeller, Gideon, Schüpbach, Simon
• Format: Text
• Language: English
• Published: American Geophysical Union 2015
• Subjects: 530 Physics; Greenland; Greenland ice core; ice core; North Greenland
• Online Access: https://dx.doi.org/10.7892/boris.72757; http://boris.unibe.ch/72757/

This study reports the chemical composition of particles present along Greenland’s North Greenland Eemian Ice Drilling (NEEM) ice core, back to 110,000 years before present. Insoluble and soluble particles larger than 0.45 μm were extracted from the ice core by ice sublimation, and their chemical composition was analyzed using scanning electron microscope and energy dispersive X-ray spectroscopy and micro-Raman spectroscopy. We show that the dominant insoluble components are silicates, whereas NaCl, Na₂SO₄, CaSO ₄, and CaCO₃ represent major soluble salts. For the first time, particles of CaMg(CO₃)₂ and Ca(NO₃)₂ 4H₂O are identified in a Greenland ice core. The chemical speciation of salts varies with past climatic conditions. Whereas the fraction of Na salts (NaCl + Na₂SO₄) exceeds that of Ca salts (CaSO₄+ CaCO₃) during the Holocene (0.6–11.7 kyr B.P.), the two fractions are similar during the Bølling-Allerød period (12.9–14.6 kyr B.P.). During cold climate such as over the Younger Dryas (12.0–12.6 kyr B.P.) ...