Entry_ID: GGD283
Entry_Title: Rock glaciers, Disko Island, Greenland
Group: Data_Set_Citation
   Dataset_Creator: Humlum, O
   Dataset_Title: Rock glaciers, Disko Island, Greenland
   Dataset_Release_Date: 1998-01-01
   Dataset_Release_Place: Boulder, Colorado USA
   Dataset_Publisher: NSIDC: National Snow and Ice Data Center
   Online_Resource: http://nsidc.org/data/ggd283.html
End_Group
Group: Personnel
   Role: Investigator
   First_Name: Ole
   Last_Name: Humlum
   Email: oleh@unis.no
   Phone: 47  79 02 33 00 
   Fax: 47   79 02 33 01 
   Group: Contact_Address
      Address: The University Centre on Svalbard, UNIS
      Address: Department of Geology
      Address: P.O. Box 156
      City: Longyearbyen
      Postal_Code: 9171
      Country: Norway
   End_Group
End_Group
Group: Parameters
   Category: EARTH SCIENCE
   Topic: Cryosphere
   Term: Frozen Ground
   Variable_Level_1: Permafrost
End_Group
Group: Parameters
   Category: EARTH SCIENCE
   Topic: Cryosphere
   Term: Frozen Ground
   Variable_Level_1: Rock Glaciers
End_Group
Group: Parameters
   Category: EARTH SCIENCE
   Topic: Land Surface
   Term: Frozen Ground
   Variable_Level_1: Permafrost
End_Group
Group: Parameters
   Category: EARTH SCIENCE
   Topic: Land Surface
   Term: Frozen Ground
   Variable_Level_1: Rock Glaciers
End_Group
Keyword: Mapping
Keyword: Meteorology
Keyword: Permafrost Properties
Keyword: Rock Glaciers
Group: Spatial_Coverage
   Southernmost_Latitude: 69.5
   Northernmost_Latitude: 70.5
   Westernmost_Longitude: -55
   Easternmost_Longitude: -52
End_Group
Group: Location
   Location_Category: CONTINENT
   Location_Type: NORTH AMERICA
   Location_Subregion1: GREENLAND
   Detailed_Location: SOUTHWESTERN DISKO ISLAND, CENTRAL WEST GREENLAND
End_Group
Data_Set_Language: English
Group: Data_Center
   Data_Center_Name: NSIDC > National Snow and Ice Data Center
   Data_Center_URL: http://nsidc.org
   Group: Personnel
      Role: Data Center Contact
      First_Name: NSIDC
      Last_Name: User Services
      Email: nsidc@nsidc.org
      Phone: 1 303 492-6199 
      Fax: 1 303  492-2468 
      Group: Contact_Address
         Address: National Snow and Ice Data Center
         Address: CIRES, 449 UCB
         Address: University of Colorado
         City: Boulder
         Province_or_State: CO
         Postal_Code: 80309-0449
         Country: USA
      End_Group
   End_Group
End_Group
Group: Data_Center
   Data_Center_Name: FGDC > Frozen Ground Data Center
   Data_Center_URL: http://nsidc.org/fgdc/
   Group: Personnel
      Role: Data Center Contact
      First_Name: FGDC
      Last_Name: User Services
      Email: nsidc@nsidc.org
      Phone: 1 303 492-6199 x
      Fax: 1 303  492-2468 x
      Group: Contact_Address
         Address: National Snow and Ice Data Center
         Address: CIRES, 449 UCB
         Address: University of Colorado
         City: Boulder
         Province_or_State: CO
         Postal_Code: 80309-0449
         Country: USA
      End_Group
   End_Group
End_Group
Group: Distribution
   Distribution_Media: FTP
   Distribution_Format: ASCII Text (.txt)
End_Group
Group: Reference

   Christiansen, H. H. 1995. Observations of Open System Pingos in a Marsh 
   Environment, Mellemfjord, Disko, Central West Greenland. Danish Journal of 
   Geography, 95, 42-48.

   Hansen, B. U.; Humlum, O; Nielsen, N.; Rasch, M. and Funch, P. 1997: 
   Meteorological Observations in 1996 at the Arctic Station, Qeqertarsuaq 
   (Godhavn), Central West Greenland. Danish Journal of Geography, Vol.97, 152-153.

   Humlum, O. 1982. Rock glacier types on Disko, central West Greenland, 
   Geografisk Tidsskrift, 82, 59-66.

   Humlum, O. 1984. Altitudinal trends of talus-derived lobate rock glaciers on 
   Disko, central West Greenland, XXV. International Geographical Congress, Royal 
   Danish Geographical Society, Occasional Papers, 7, 35-39.

   Humlum, O. 1987. Glacier behaviour and the influence of upper-air conditions 
   during the Little Ice Age in Disko, central West Greenland. Danish Journal of 
   Geography, 87, 1-12.

   Humlum, O. 1988a. Rock glacier appearance level and rock glacier initiation 
   line altitude: a methodological approach to the study of rock glaciers, Arctic 
   and Alpine Research, 20, 160-178.

   Humlum, O. 1988b. Natural cairns on rock glaciers as an indication of a solid 
   ice core, Geografisk Tidsskrift, 88, 78-82.

   Humlum, O. 1992. Observations on Rock Moisture Variability in Gneiss and 
   Basalt under Natural, Arctic Conditions. Geografiska Annaler, 74A, 197-205.

   Humlum, O. 1996. Origin of Rock Glaciers: Observations from Mellemfjord, Disko 
   Island, central West Greenland, Permafrost and Periglacial Processes, 7, 
   361-380.

   Humlum, O. 1997. Active Layer Thermal Regime at three Rock Glaciers in 
   Greenland. Permafrost and Periglacial Processes, Vol.8, p. 383-408.

   Humlum, O., Christiansen, H. H., Hansen, B. U., Hasholt, B., Jakobsen, B. H., 
   Nielsen, N. and Rasch, M. 1995. Holocene Landscape Evolution in the 
   Mellemfjord Area, Disko Island, Central West Greenland: Area Presentation and 
   Preliminary Results. Danish Journal of Geography, 95, 28-41.

   Humlum, O.; Nielsen, N. and Hansen, B. U. 1996: Meteorological Observations in 
   1995 at the Arctic Station, Qeqertarsuaq (Godhavn), Central West Greenland. 
   Danish Journal of Geography, 96:119-122.  Nielsen, N.; Humlum, O.; Hansen, B. 
   U.; and M. Rasch. 1995: Meteorological observations at Arctic Station, 
   Qeqertarsuaq (Godhavn), Central West Greenland. Danish Journal of Geography, 
   95:97-104.

   Rasch, M. and Nielsen, N., 1994: Holocene relative sea-level changes indicated 
   by morphostratigraphic sequences; Signifik, Disko Island, West Greenland. 
   Danish Journal of Geography, 94: 37-45.  Rasch, M. and Nielsen, N., 1995: 
   Coastal morpho-stratigraphy and Holocene relative sea level changes at 
   Tuapaat, southeastern Disko Island, central West Greenland. Polar Research, 
   14: 277-289.

   Rasch, M., Christiansen, H. H., Hansen, B. U., Hasholt, B., Humlum, O., 
   Jakobsen, B. H. and Nielsen, N. 1996. Greenland Landscape Elements as 
   Indicators of Rapid Environmental Change. In: Geoindicators: Assessing Rapid 
   Environmental Changes in Earth Systems, Berger, A.R. and Iams, W.J. (eds.) 
   Balkema Publishers, Holland, p. 69-92.

   Weidick, A. 1968. Observations on some Holocene glacier fluctuations in West 
   Greenland. Meddelelser om Grnland, 164(6), 202p.

End_Group
Group: Summary

   Disko Island (8600 km2) is situated west of central  mainland Greenland. The 
   island is part of the Tertiary volcanic province of West Greenland and is 
   mainly made up by lavas. The landscape is a plateau basalt landscape with 
   cirque carved lava plateaus and U-shaped valleys and fjords. Rock glaciers are 
   frequent in Disko Island (Humlum, 1982). In southern Disko Island, about 60 km 
   SSE of the two study sites, meteorological observations have been carried out 
   since 1923 in the village of Godhavn. The present (1961-1990) mean annual air 
   temperature is -3.9 C, the coldest month is March (-15.1 C), and July is the 
   warmest month (7.1 C). The mean annual precipitation at Godhavn is about 400 
   mm water equivalent. Most of the precipitation (75 %) usually falls during the 
   period June to December, associated with advection of moist, maritime air 
   masses from the south and southwest along the Davis Strait. The remaining part 
   of the year is comparatively dry, as it is dominated by cold and dry katabatic 
   air masses flowing off the Greenland Ice Sheet to the east. Approximately 
   60-70 % of the mean annual precipitation is snow and in Godhavn a persistent 
   snow cover is registered from late September to late May.

   No systematic mapping of permafrost or permafrost related terrain features 
   have been carried out in this part of West Greenland. Weidick (1968), however, 
   places Disko Island within the zone of continuous permafrost. This is 
   supported by the occurrence of open system pingos (Christiansen, 1995) and 
   numerous rock glaciers (Humlum, 1982, 1984, 1988a, 1988b, 1996; Humlum et al., 
   1995; Rasch et al. 1996), which are geomorphic indications of the presence of 
   widespread permafrost in Disko Island. Adopting a standard continental 
   geothermal gradient of about 0.033 C m-1, the mean annual air temperature of 
   -7.5 C (1991-96) indicates a potential permafrost thickness of about 175-225 
   m. This estimate is presumably somewhat conservative, as the Little Ice Age 
   annual air temperature presumably was about 2C below modern values (Humlum, 
   1996), which would provide conditions for a somewhat thicker permafrost layer 
   than is suggested by modern meteorological values. The high frequency of rock 
   glaciers on Disko Island is presumably derived from high rock weathering rates 
   (Humlum, 1992). These data are presented on the CAPS Version 1.0 CD-ROM, June 
   1998.

End_Group
Metadata_Name: CEOS IDN DIF
Metadata_Version: 9.7
DIF_Creation_Date: 1998-01-01
Last_DIF_Revision_Date: 2012-08-24
DIF_Revision_History: added creator and publisher info