Particle-laden Eurasian Arctic sea ice: observations from July and August 1987

Abstract

During the summer 1987 expedition of the polar research vessel 'Polarstern' in the Eurasian Basin of the Arctic Ocean, sea ice at about 84-86"N and 2@3OoE was found to have high concentrations of particulate material. The particle-laden ice occurred in patches which often darkened more than half the ice surface at our northernmost positions. Much of this ice appeared to be within :he Siberian Branch of the Transpolar Drift stream, which transports deformed, multi-year ice from the Siberian shelves westward across the Eurasian Basin. Lithogenic sediment, which is the major component of the particulate material, may have been incorporated during ice formation on the shallow Siberian seas. Diatoms collected from the particlerich ice surfaces support this conclusion, as assemblages were dominated by a marine benthic species similar to that reported from sea ice off the coast of northeast Siberia. Based on drift trajectories of buoys deployed on the ice it appears that much of the particle-laden ice exited the Arctic Ocean through the Fram Strait and joined the East Greenland Current. Very different sea ice characteristics were found east of the Yermak Plateau and north of Svalbard and Frans Josef Land up to about 83-84"N. Here sea ice was thinner, less deformed, with lower amounts of lithogenic sediment and diatoms. The diatom assemblage was dominated by planktonic freshwater species. Trajectories of buoys deployed on sea ice in this region indicated a tendency for southward transport to the Yermak Plateau or into the Barents Sea.

Changes in Driftwood Delivery to the Canadian Arctic Archipelago: The Hypothesis of Postglacial Oscillations of the Transpolar Drift

“…Published observations of the distribution of drifting logs in the Arctic Ocean are rare (Pfirman et al, 1989). However, Mackenzie River driftwood is abundant along the coastline both east and west of its delta, as has long been known (Kindle, 1921;Eurola, 1971).…”

Regional variations in provenance and abundance of ice-rafted clasts in Arctic Ocean sediments: implications for the configuration of late Quaternary oceanic and atmospheric circulation in the Arctic

“…Most studies of ice-rafting in the Eurasia basin have also concentrated on the fine-grain fraction (Pfirman et al, 1989(Pfirman et al, , 1990Bischof, 1990;Nürnberg et al, 1994;Nørgaard-Pedersen, 1997;Landa et al, 1998).…”

Pivotal role of sea ice sediments in the seasonal development of near-shore Arctic fast ice biota

“…Nürnberg et al 1994), and such sediment-rich patches are particularly common in the Chukchi and Beaufort Seas (Barnes et al 1982, Osterkamp & Gosink 1984, Eicken et al 2005, forming so-called 'dirty ice' or 'sediment-laden ice'. Up to 50% of the entire Arctic ice cover can contain visually detectable amounts of sediment (Pfirman et al 1989, Reimnitz et al 1993, Nürnberg et al 1994, which is transported across the offshore Arctic with the ice drift.Sea ice sediments located in the top 20 to 30 cm of the ice alter the spectral albedo, whereas total sediment load affects light transmission (Light et al 1998). Osterkamp and Gosink (1984) observed, for example, about 10-fold higher attenuation coefficients for sediment-laden fast ice compared to clean ice.…”