Toolik 1km

General Information

Created: 2013-12-27 16:18:31
Modified: 2014-02-03 13:08:07

Active: Yes
Country:United States
Site:Toolik Lake
CALM-Code:U12 A
Responsible Countries: United States,
Timezone:UTC/GMT -09:00 hours
Vegetation Type:Tundra
Responsible Person:Nikolay Shiklomanov
Offset:100 m


This grid occupies the flanks of a bedrock-cored hill adjacent to Toolik Lake. Moist acidic tundra has developed atop glacial tills. Vegetation and soils vary with slope, aspect, and drainage, and are discontinuous (Hinkel & Nelson, 2003).



1-sq km grid consists of a square array of surveyed permanent stakes separated by 100 m, yielding an 11 × 11 array of sampling nodes on each grid. Thaw depth and snow sampling was conducted twice by manual probing at each stake. The two values for each sampling point are averaged, yielding a maximum of 121 data points per grid per probing date. The active layer was not measured at locations where grid points intersect rocks or deep water.

The soil climate station was established in September of 1998 and is located near Toolik Lake, Alaska, at the University of Alaska/National Science Foundation Research camp. The station is located within the 1 km CALM u12A grid. The elevation is about 759 m (2490 ft). This station monitors air temperature, precipitation, soil temperature at various depths to a maximum of 120 cm, and soil water contents at 9, 12, 38, 39, and 68 cm depths. Measurements are made at 20-minute intervals and averaged and recorded every hour.

Soil temperature and soil moisture metadata and data are also available at

Slope:1 °
Permafrost Zone:Continuous
Vegetation:Tussock-graminoid, dwarf-shrub tundra and prostrate-dwarf-shrub, moss tundra (moist acidic and nonacidic)
Hydrology:Dry on top of the ridges, wet to saturated in the watertrack
Landform:Glaciated foothills
Lithology:Ruptic-Histic Aquiturbel Typic Aquiturbel Organic Layer thikness:15 (cm); mineral texture -- silty loam /silty clay/gravelly loam (coarce glacial till)
Access Timeseries
Bibliographic References
Hinkel, K.M. Nelson, F.E. 2003. Spatial and temporal patterns of active layer thickness at Circumpolar Active Layer Monitoring (CALM) sites in northern Alaska, 1995-2000. Journal of Geophysical Research, Vol.108, No. D2, 8168.
Shiklomanov, N.I. and F.E. Nelson. 2003 Climatic variability in the Kuparuk region, north-central Alaska: optimizating spatial and temporal interpolation in a sparse observation network. Arctic, 56: 136-146.
Shiklomanov, N.I. and F.E. Nelson. 2003 Statistical representation of landscape-specific active-layer variability. In Phillips, M., Springman, S. M., and Arenson, L. U. (eds.), Proceedings of the Eighth International Conference on Permafrost, vol. 2. Lisse: A.A. Balkema, 1039-1044.
Walker D.A., Jia G.J., Epstein H.E., Raynolds M.K., Chapin III F.S., Copass C., Hinzman L.D., Kane D., Knudson J.A., Maier H., Michaelson G.J., Nelson F.E., Ping C.L., Shiklomanov N.I., Romanovsky V.E., Shur Y. 2003 Vegetation-soil-thaw-depth relationships along a Low Arctic bioclimatic gradient, Alaska: Synthesis of information from the Atlas studies. Permafrost and Periglacial Processes, 14: 103-123.
Shiklomanov N. I. and F. E. Nelson, F. E., 2002. Active-layer mapping at regional scales: a 13-year spatial time series for the Kuparuk region, north-central Alaska. Permafrost and Periglacial Processes, 13: 219-230.
Klene A.E., Nelson F.E., and N.I. Shiklomanov. 2001 The n-factor as a tool in geocryological mapping: seasonal thaw in the Kuparuk River Basin, Alaska. Physical Geography, 22(6): 449-466.
Klene A.E., Nelson F.E., Shiklomanov N.I., and K.M. Hinkel. 2001 The n-factor in natural landscapes: Variability of air and soil-surface temperatures, Kuparuk River basin, Alaska. Arctic, Antarctic and Alpine Research, 33(2): 140-148.
Nelson, F.E., Shiklomanov, N.I., and G.R. Mueller. Variability of active-layer thickness at multiple spatial scales, north-central Alaska, USA. 1999 Arctic, Antarctic, and Alpine Research, 31(2): 179-186.
Walker, D.A., Auerbach, N.A., Bockheim, J.G., Chapin, F.S., Eugster, W., King, J.Y., McFadden, J.P., Michaelson, G.J., Nelson, F.E., Oechel, W.C., Ping, C.L., Reeburg, W.S., Regli, S., Shiklomanov, N.I., and G.L. Vourlitis.1998 Energy and trace-gas fluxes across a soil pH boundary in the arctic. Nature, 394(6692): 469-472.
Nelson F.E., Shiklomanov, N.I., Mueller G.R., Hinkel K.M., Walker D.A., and J.G. Bockheim.1997 Estimating active-layer thickness over a large region: Kuparuk River basin, Alaska, USA. Arctic and Alpine Research, 29(4): 167-378.
Nelson, F.E., Hinkel, K.M., Shiklomanov, N.I., Mueller, G.R., Miller, L.L., and D.A., Walker. Active-layer thickness in north central Alaska: systematic sampling, scale, and spatial autocorrelation. 1998 Journal of Geophysical Research-Atmospheres, 103(D22): 28963-28973.
Bockheim, J.G., Walker, D.A., Everett, L.R., Nelson, F.E. and N.I. Shiklomanov. 1998 . Soils and cryoturbation in moist nonacidic and acidic tundra in the Kuparuk River basin, Arctic Alaska, USA. Arctic and Alpine Research, 30(2): 166-174.
Shiklomanov, N.I. and F.E. Nelson. Analytic representation of the active layer thickness field, Kuparuk River basin, Alaska. 1999 Ecological Modelling, 123: 105-125.
Nelson, F.E., Outcalt, S.I., Brown, J., Shiklomanov, N.I., and K.M. Hinkel. Spatial and temporal attributes of the active-layer thickness record, Barrow, Alaska, USA, 1998 Proceedings of the Seventh International Conference on Permafrost. Centre de etudes nordiques de l'Universite Laval, Laval, Quebec, Canada, Yellowknife, NWT, Canada, pp. 797-802

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U12/13 Toolik Lake

Longitude:-149.6 °
Latitude:68.616667 °
Elevation:741.639343 m
Meta Data Completeness
Percentage of information fields provided for this monitoring site!