Ninth International Conference on Permafrost ... - IARC Research

A Provisional Soil Map of the Transantarctic Mountains, AntarcticaMegan R. BalksEarth and Ocean Sciences, University of Waikato, Private Bag 3105, Hamilton, New ZealandMalcolm McLeodLandcare Research, Private Bag 3172, Hamilton, New ZealandJames G. BockheimDepartment of Soil Sciences, University of Wisconsin, 1525 Observatory Drive, Madison, WI 53706-1299, USAIntroductionA provisional soil map has been prepared for theTransantarctic Mountain region of Antarctica in three wallsize(A0) sheets, each at a scale of 1:1,000,000. The mapscontribute to the ANTPAS (Antarctic Permafrost and Soils)effort to develop a soil map of the Antarctic continent andpdf files of the maps will be made available on the ANTPASwebsite http://erth.waikato.ac.nz/antpas/.The Transantarctic Mountains extend 3500 km across theAntarctic continent from 69°S in northern Victoria Land to87°S in the upper Scott Glacier region. The TransantarcticMountain region has an ice-free area of 21,000 km 2 , whichconstitutes 42% of the total ice-free area (49,500 km 2 ) ofAntarctica. The climate ranges from ultraxerous, withtemperatures rarely exceeding 0°C, on the inland marginsof the Transantarctic Mountains, to subxerous, withtemperatures greater than 0°C for several weeks in summerand liquid water present for short periods, on coastal margins(Campbell & Claridge 1987). Soil parent materials arepredominantly glacial tills with mixed lithologies, mainlydominated by sandstones, granites, and dolerites. Altituderanges from sea level to peaks of over 2500 m with manysteep valley sides. Topography has a strong influence onlocal microclimates. Soil surfaces range from Holoceneto Pliocene in age. Over much of the area the influence oforganisms on soil development is limited to microbial life.In warmer, moister, coastal sites small areas with extensivemoss coverage occur and penguins have an impact on soildevelopment, providing guano-rich soils, in small areas ofnesting colonies.While the general pattern and properties of Antarctic soilsare well known (e.g., Tedrow & Ugolini 1966, Campbell &Claridge 1987, Bockheim 2002), little attention was paidto mapping the spatial distribution of Antarctic soils untilrecently, when soil maps of the Wright Valley (McLeodet al. 2008, this proceedings), the McMurdo Dry Valleys(Bockheim & Mcleod 2008), and the Seabee Hook (Hofsteeet al. 2006) have been published. This paper is a “partner”to Bockheim et al. (2008, this proceedings), which describespermafrost maps of the Transantarctic Mountains.MethodsThe soil maps have been compiled from existingdata, including published data and data archived by theNational Snow & Ice Data Center (http://nsidc.org/cgi-bin/get_metadata.Pl?id-ggd221) and New Zealand LandcareResearch (http://www.landcareresearch.co.nz). Scanned andgeo-rectified 1:250,000 topographic maps prepared by theU.S. Geological Survey (http://usarc.usgs.gov) were joinedin ArcGIS 9.2 and used as a base map. Aerial photographand topographic map interpretation were used to extrapolateto areas where field data are limited. Because some partsof the region are more readily accessible, with more dataavailable than others, a “confidence” rating was applied toeach map unit as described in McLeod et al. (2007). Recentfieldwork was undertaken by the authors in the DarwinGlacier, Wright Valley, and Cape Hallet areas to add toexisting data and corroborate our data, topographic map, andphoto, interpretations.Table 1 Provisional physiographic legend.*Soils of the subxerous coastal regionsFormed on patterned groundTypic Haploturbels + Typic HaplorthelsFormed on ice-core driftGlacic Haploturbels + Glacic HaplorthelsFormed within penguin coloniesOrnithic HaplorthelsFormed on nunataks or rock outcropsLithic Haploturbels + Lithic HaplorthelsFormed in areas with patterned ground and rock outcropsLithic Haploturbels + Orthic Haploturbels + LithicHaplorthels + Typic HaplorthelsSoils of the xerous and ultraxerous inland areasFormed in areas with dry permafrost to > 70 cm depth andno patterned groundTypic AnhyorthelsFormed on patterned ground with dry-permafrost to > 70 cmdepthTypic Anhyorthels + Typic AnhyturbelsFormed on patterned ground with ice-cement or seasonallymoist soil at < 70 cm depthTypic Haploturbels + Typic HaplorthelsFormed on patterned ground with ice-cement or seasonallymoist soil at < 70 cm depth and rock outcropsTypic Haploturbels + Typic Haplorthels + LithicHaploturbels + Lithic HaplorthelsFormed on ice cored drift with dry-permafrost to > 70 cmdepthGlacic Anhyturbels + Glacic AnhyorthelsFormed on nunataks or rock outcrops including areas withdry permafrost to >70 cm depthLithic Anhyorthels + Typic Anhyorthels* + denotes a soil association.13