Long Term Ecological Research (nematode experimental area) site investigation of soil properties; this site (LTER 1) was chosen for daily repeat sampling to see if there were measurable changes in soil moisture over the length of the sampling period; this sampling is the eleventh at this site and took place at the start of a snowfall event
Description:
LTM Datalogger plot, on the south side of Lake Hoare, approximately 100m south of Lake Hoare, on the lower slope of a ridge which forms part of an undulating ridge and gully/basin topography; the soil sampling site was on the south and upslope side of the LTM datalogger plot, which comprises a series of plastic cones covering the soil surface; the site has an even, stony gravel surface with slope increasing towards the ridge just to the south; this sampling site is designated LTER 1k and was immediately alongside LTER 1j
Altitude:
90 m
Aspect:
NNE
Slope:
5 °
Location Data
Observer
IBC
GPS
Yes
Latitude Longitude DMS
77° 37.99' S 162° 52.86' E
Latitude Longitude DD
-77.63320 162.88100
Latitude longitude precision DD
0.00008 0.00008
Locality
Near Lake Hoare, Taylor Valley, McMurdo Dry Valley region, Transantarctic Mountains
Survey
Lake Bonney Quadrangle, Antarctic 1:50,000 Topographic Series, USGS 1975
Climate
Soil climate zone:
Coastal mountain
Estimated mean annual temperature:
-20
°C
Frozen ground depth:
44 cm
Frozen type:
Hard ice-cemented
Frozen comment:
44cm
Geology
Geological setting:
The deposit is unweathered Ross I till, possibly derived from the Canada Glacier but almost certainly with an up-valley influence because of the presence of marble clasts from basement rocks; the tills may be fluvio-glacial owing to complex depositional ice-marginal processes as the sand % generally increases downwards while there are noticeably more coarse clasts at the surface
Patterned ground:
Moderately developed 10x20m elongate nets with 20cm deep troughs, 75cm wide
Surface weathering or surface features:
A few clasts slightly oxidised and some weak ventifaction; grey calcium carbonate coatings abundant beneath many surface clasts
Soil
Soil parent material:
Predominantly granite/gneiss/schist sandy gravel with minor amounts of dolerite, volcanic (scoria), sandstone and marble
Previous disturbance:
Site probably disturbed by foot traffic activity during biological research activities near the site
Xerous to subxerous; light snow just beginning to fall at 9 30am
Biological activity:
Nil observed at site, nematodes present in adjacent soil; some green algae beneath marble clasts in the general area
Profile Description
Horizon
Depth
Description
904a
-1
–
0
cm
surface cobbles, pebbles, granules and sand; unstained to weakly stained; subangular to subrounded; calcium carbonate coatings beneath many clasts,
904b
0
–
2
cm
light olive grey (5Y 6/2) sandy gravel (57% >2mm 43% <2mm); loose; larger rock particles subangular with smaller particles rounded to subrounded; carbonate coatings beneath larger clasts; diffuse boundary,
904c
2
–
10
cm
light olive grey (5Y 6/2) sandy gravel (57% >2mm 43% <2mm); loose; larger rock particles subangular with smaller particles rounded to subrounded; abundant carbonate coatings around larger and smaller clasts; diffuse boundary,
904d
10
–
18
cm
light olive grey (5Y 6/2) sandy gravel (57% >2mm 43% <2mm); lightly frosted at 15cm; larger rock particles subangular with smaller particles rounded to subrounded; abundant carbonate coatings around larger and smaller clasts; sharp boundary,
904e
18
–
25
cm
light olive grey to pale olive (5Y 6/2 - 6/3) gravelly sand; firmly frozen at 19cm; larger rock particles subangular with smaller particles rounded to subrounded; many carbonate coatings around larger and smaller clasts; diffuse boundary,
904f
25
–
43
cm
light olive grey to pale olive (5Y 6/2 - 6/3) gravelly sand; firmly frozen; larger rock particles subangular with smaller particles rounded to subrounded; few carbonate coatings; sharp boundary,
904g
43
–
47
cm
light olive grey to pale olive (5Y 6/2 - 6/3) gravelly sand; very hard; ice-cemented; on; hard ice-cemented ground