Ice Core Archives of Mineral Dust - Mineral Dust: A Key Player in the Earth System - page 461

Fig. 18.2 Example of line scan image from the glacial part of the Greenland NGRIP ice core
during the last glacial period (depth 1,836.45-1,837 m, approximately 26.1 ka ago). Brighter areas
indicate greater dust concentrations

18.3 Dust Records

18.3.1 Southern Hemisphere

18.3.1.1 Antarctica

18.3.1.1.1 Early Discoveries

The first deep ice core drilling in Antarctica was the US “Byrd” program, drilled in
West Antarctica in 1968. Thompson et al. ( 1975 ) reported microparticle concentra-
tions in the Byrd core, identifying a correlation between temperatures (determined
from the • 18 O isotope ratio) and particle concentrations. They observed particles
smaller than 1 m in diameter and attributed these to emissions from circum-Pacific
volcanoes. On the assumption that Byrd dust originated from volcanoes, they were
not able to explain the greater-than fourfold increase in dust concentrations during
the Last Glacial Maximum (LGM) between 12 and 21 ka ago (Johnsen et al. 1972 ).
The Byrd record was followed by more detailed dust records from the first Dome
C ice core, drilled in 1977 to a depth of 905 m (Petit et al. 1981 ; Royer et al. 1983 ),
and the first Vostok ice core drilled in the early 1980s (De Angelis et al. 1984 ). The
Dome C record spanned 32 ka, showing that dust flux variations occurred across
Antarctica and were of a similar magnitude. Petit and co-workers used sea salts (Na,
Cl), terrestrial elements (Mg, V) and a volcano proxy (Zn) to attribute the dust to
continental sources. Considering dust records from Vostok and D10 (a site 260 km
inland of Dumont D'Urville) they identified a smaller, 7-fold, concentration change
over the deglacial transition.

18.3.1.1.2 Longer and More Detailed Records

De Angelis et al. ( 1987 ) reported Na and Al concentrations in a new Vostok record,
extended to 2,200 m depth and approximately 160 ka, finding many novel features
in the dust record. They confirmed the strong link between temperature and dust
fluxes and showed that dust fluxes were lower during the early glacial period, when
temperatures and global ice coverage were also less severe. They reported a dust
peak at the end of the penultimate glacial period, approximately 150 ka ago. They
also identified that “full” glacial conditions, with very high dust fluxes, were only