Research area #4: Aeolian processes

Antarctic aeolian materials

Aeolian (wind-derived) processes play an important role in the global transport of both geological and biological materials that, in turn, can greatly impact the biogeochemistry of terrestrial and aquatic ecosystems. Arid regions, particularly polar and alpine desert environments, have diminished landscape connectivity compared to temperate regions due to limited and/or seasonal hydrological processes. For these environments, aeolian processes play a particularly important role in landscape evolution and biotic community vitality through nutrient and solute additions.

Big Spring Number Eight (BSNE) collector in the McMurdo Dry Valleys

The McMurdo Dry Valleys (MDV) are the largest ice-free area in Antarctica and are potentially a major source of aeolian material for the continent. We evaluated the role of drainage, foehn, and coastal winds in transporting nutrients. We collected aeolian materials near the surface and ~100 cm above the surface and found:

1. Material in Taylor Valley was generally transported down valley from Taylor Glacier toward the coast. Summer up-valley winds are weaker and did not transport significant material far inland.
2. Nitrate rich material originating from the higher-elevation, inland locations may help to support younger N-limited soils, while lower elevations could be source of phosphorus for older P-limited soils during times of high particle transport.
3. Lower collection height samples demonstrated little intervalley connectivity, while the uppermost samples demonstrated some mixing, altering the chemical continuum.

McMurdo Dry Valleys, Antarctica

In the Southern Hemisphere, the major sources of dust and other aeolian materials are from Patagonia, South Africa, Australia, and New Zealand. However, little information exists on modern Antarctic dust sources, transport, and its role in the Southern Hemisphere dust cycle. We evaluated the trace and rare earth element geochemistry and mineralogy of materials from the McMurdo Dry Valleys.

We found that low elevation and coastal locations (with respect to the Ross Sea) are dominated by local sources, but high elevation and inland locations may have accumulated both local materials and dust from other distant Southern Hemisphere sources. By geochemically “fingerprinting” aeolian materials from the Dry Valleys, we can better inform future studies on the transport of materials within Antarctica and between Southern Hemisphere land masses.