THE UNIVERSITY OF WISCONSIN PERMAFROST/GROUND ICE/SOILS DATABASE J.G. Bockheim

Areas:  McMurdo Dry Valleys  Transantarctic Mountains –Darwin Glacier area –Beardmore Glacier area  North Victoria Land  Ellsworth Mountains

Antarctic Soils Database:  473 sites throughout McMurdo Dry Valleys (MDV)  Surface boulder lithology, frequency, and weathering features  Detailed soil descriptions  Observations of patterned ground, permafrost, and ground-ice forms  Laboratory characterization of 46% of soils  Classification of soils in SOIL TAXONOMY, WRB

Unique Features of Antarctic Soils Database:  Product of pedologist-glacial geologist/geomorphologist with goal to reconstruct glacial history of MDV  Description and sampling protocol unchanged over 12-yr period ( )  Rigorous protocol for site/soil descriptions and laboratory characterization  Soil pits dug by hand to at least 1 m  Standard soil horizon nomenclature applied with some adaptations  Soils classified into ST, WRB

Approach: –Select site according to “master relative chronology” –Locate on aerial photograph, topographic map (1:50,000) –Determine corrected elevation –Randomly locate plot on moraine crest –Measure surface boulder weathering features –Describe and sample modal soil profile –Restore site –Characterize soils in laboratory –Electronic storage of data –GIS (ArcInfo) 2000-present --Utilize data for constructing permafrost/ground ice and soil maps

Measuring Surface Boulder Weathering Features in the MDV

Excavating Soil in Upper Arena Valley

Describing and Sampling Soil in Wright Valley

A GIS For The McMurdo Dry Valleys, Antarctica TheVALMAP (Valleys in Antarctica: Layered Mapping, Analysis, and Planning) Project has produced a Geographic Information System for the McMurdo Dry Valleys, Antarctica, referred to as the MDV GIS. The MDV GIS contains, in a single projection, layers of mapped information, such as images, topographic contours, and geology, to which data are attached according to the "coverage geographic data model" of the Environmental Systems Research Institute (ESRI).

Ecoclimaticregion Number of sites % of total Coastal (C) Inland valley floor (IVF) Inland valley side IVS) Upland valley (UV) Polar fringe (PF) Total Distribution of Sites by Ecoclimatic Region

Location of Sampling Sites

Permafrost Form in the MDV

FormNumber % of total Age Ky BP EcoclimaticregionDry32769>200 IVF, IVS Ice- cemented 14631<200 C, IVS, UV, PF Permafrost form in the MDV (upper 1 m)

Ground ice Number % of total Ecoclimatic region Ice-wedgepolygons6113 C, IVF Ice-coreddrift143 IVS, IVF, C Rock glaciers 163 UV, IVS Ground ice the MDV

Ice-Cored Drift

Rock Glacier

Differentiating Sand-Wedge and Ice-Wedge Polygons

Ground-Ice Features in the MDV

Sand-Wedge Cast

Ice-Wedge Cast

Recession of ice-cemented Permafrost in the MDV Sand-wedge casts

Weathering stage BoulderconditionSoilcolorsSoil Horizon- ation SaltstagePermafrostdepth 1Freshangular5Yminimal0shallow 2 Light staining, some disint. 10YR 6/3- 2.5Y 6/2 weak 1 or 2 shallow 3 Polish, stained 10YR 5/3- 2.5Y 6/4 distinct3Mod.deep 4 Ventif., strong cavern. 10YR 5/4 Verydistinct4deep 5 Few boulders, strong pavement 1-YR 4/4- 5YR 5/8 Verydistinct5deep 6 Residual pavement 7.5YR 5/6- 5YR 4/8 Verydistinct6Shallow-deep Weathering Stages of Antarctic Landforms/Soils

McMurdo Sound Taylor Valley Arena Valley Wright Valley Alpine glaciers Numerical age Weath. stage Taylor I drift Alpine I drift 3.7 Ka 1 Ross Sea drift (Ross I) Wright Lower drift Ka 1 Taylor II drift (Bonney) Alpine IIa drift Ka 2 Marshall drift (Ross II) Onyx drift Ka 2 Taylor III drift Alpine IIb drift Ka 3 (Ross III) Loop moraine 450 Ka? 3 (Ross IV) Wright drift ?4 Taylor IVa Alpine III (IIIa) Ma 4 Taylor IVb Alpine IV (IIIb) 2.7->3.7 Ma 5 Quartermain drift Peleus drift 3->3.8 Ma 6 Sirius drifts Ma 6 Glacial Chronology of the MDV

Distribution of Landforms/Soils by Weathering Stage, MDV

Salt stage Morphogenetic form EC (dS/m) Approx. age 0None<0.6 <10 ka 1 Coatings beneath stones ka 2 <20% of horizon with flecks 1-2 mm ka 3 >20% of horizon with flecks 1-2 mm ka 4 Weakly cemented salt pan ka - ~1.7 Ma 5 Strongly cemented salt pan ~1.7 – 2.5 Ma 6 Indurated salt pan ~>2.5 Ma Morphogenetic Salt Stages in Antarctic Soils

Morphogenetic Salt Stage for Soils in the MDV

Example of Soil With Stage 5 Salts

Location of Soils With Salt Pans in the MDV

Chemistry of Salts in Antarctic Gelisols

Antarctic Soil Showing Intense Cryoturbation (Anhyturbel)

Ecoclimatic zone Salic Anhyorthels Typic Anhyorthels Other Anhyorthels Typic Anhyturbels Other Anhyturbels Total Coastal Inland valley floor Inland valley side Upland valley Plateau fringe Total Classification of Soils in the MDV

Conclusions:  Dry permafrost pervasive in IVF and on older surfaces in IVS and UV  Ground-ice features are common in the MDV  Sand-wedge casts offer promise in reconstructing paleoclimate  Soil development rates: IVF > IVS, UV > PF > C  70% of soils of MDV are Anhyorthels reflecting lack of cryoturbation because of low soil moisture