848

Site number:

848

Authors:

IBC, MRB, JK

Date recorded:

1999/01/16

Reason Sampled:

Active layer/permafrost properties and instrumentation for measurement of soil thermal moisture and site climate

Description:

About 150m NW of the Scott Base buildings below the crest of a small knoll on an otherwise uneven and sloping landsurface; the microtopography is hummocky old lavaflow with small steps of less steeply sloping ground; the surface is bouldery with scoria clasts up to 40cm

Altitude:

70 m

Aspect:

SSW

Slope:

4 °

Climate

Soil climate zone:

Coastal Antarctic

Estimated mean annual temperature:

-18 °C

Frozen ground depth:

30 cm

Frozen type:

Hard ice-cemented

Frozen comment:

30cm

Geology

Geological setting:

Rocks of the area are McMurdo Volcanics with extensive scoria flows; in the Last Glaciation an expanded Ross Ice Shelf covered the region and small amounts of foreign rock types (sandstone, granite) as smaall particles are present

Patterned ground:

Small net polygons, 4m diamater with trough width 30cm and depth 15cm

Surface weathering or surface features:

Some slight polish on finer grained casts; CaCo3 coatings on undersides of larger clasts

Soil

Soil parent material:

Fragmented bouldery scoria locally derived drift

Previous disturbance:

Foot traffic disturbance likely

Soil weathering stage:

1 (Campbell & Claridge 1975)

Soil moisture status:

Oceanic subxerous; the site receives considerable early summer snowfall and there is appreciable thaw in the area; probably no liquid water runoff but direct snow thaw into the soil at times

Biological activity:

small patches of yellow lichen and sparse moss