Loess deposits In Lower Adventdalen, Spitsbergen

Bryant, Ian

doi:10.3402/polar.v1982i2.7006

Cited by 20 publications

(34 citation statements)

References 4 publications

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“…Grain size was classified using the Wentworth scale into four groups: medium to very coarse sand (‐1–2 φ), coarse silt to fine sand (2–5 φ), fine to medium silt (5–8 φ) and clay (≥8 φ). This classification is useful in distinguishing between colluvial/alluvial and aeolian sediments because loess in Adventdalen is mainly composed of coarse silt to fine sand (2–5 φ) (Bryant, ).…”

Section: Methodsmentioning

confidence: 99%

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Soil Physical and Environmental Conditions Controlling Patterned-Ground Variability at a Continuous Permafrost Site, Svalbard

Watanabe

Matsuoka

Christiansen³

et al. 2016

Permafrost and Periglac. Process.

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This study examines soil physical and environmental conditions controlling patterned‐ground variability on an alluvial fan in a continuous permafrost landscape, at Adventdalen, Svalbard. On‐site monitoring of ground temperature, soil moisture and snow depth, laboratory analyses of soil physical properties and principal component analysis indicate that the distribution of patterned ground depends primarily on soil texture, soil moisture and the winter ground thermal regime associated with snow cover. Mudboils and composite patterns (mudboils surrounded by small polygons) occupy well‐drained areas composed of clay‐rich aeolian sediments. Compared to mudboils, composite patterns show a sharper contrast in soil texture between barren centres and vegetated rims. Hummocks filled with organic materials develop on poorly drained lowlands associated with a shallow water table. Ice‐wedge polygons are dominant on sandy loess‐covered areas where the local wind regime minimises snow cover, enhancing ground cooling that promotes thermal contraction cracking. Copyright © 2016 John Wiley & Sons, Ltd.

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Section: Methodsmentioning

confidence: 99%

“…The development of the fans reflects long‐lasting uplift due to isostatic rebound of the deglaciated valley, and downcutting by the Adventelva river. Loess has preferentially accumulated at the river bank margins, originating from deflation of fluvial loams deposited in the floodplain (Bryant, ).…”

Section: Study Area and Sitementioning

confidence: 97%

Soil Physical and Environmental Conditions Controlling Patterned-Ground Variability at a Continuous Permafrost Site, Svalbard

Watanabe

Matsuoka

Christiansen³

et al. 2016

Permafrost and Periglac. Process.

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“…) and pingos (Ross et al . ) on adjacent loess‐covered terraces (Bryant ) reflect the presence of permafrost. Alluvial fans spread out at the mouths of tributary valleys (Sørbel et al .…”

Section: Study Areamentioning

confidence: 99%

Holocene permafrost history and cryostratigraphy in the High‐Arctic Adventdalen Valley, central Svalbard

Cable

Elberling

Kroon

2017

Boreas

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This paper presents the history and cryostratigraphy of the upper permafrost in the High‐Arctic Adventdalen Valley, central Svalbard. Nineteen frozen sediment cores, up to 10.7 m long, obtained at five periglacial landforms, were analysed for cryostructures, ice, carbon and solute contents, and grain‐size distribution, and were 14C‐ and OSL‐dated. Spatial variability in ice and carbon contents is closely related to the sedimentary history and mode of permafrost aggradation. In the valley bottom, saline epigenetic permafrost with pore ice down to depths of 10.7 m depth formed in deltaic sediments since the mid‐Holocene; cryopegs were encountered below 6 m. In the top 1 to 5 m, syngenetic and quasi‐syngenetic permafrost with microlenticular, lenticular, suspended and organic‐matrix cryostructures developed due to loess and alluvial sedimentation since the colder late Holocene, which resulted in the burial of organic material. At the transition between deltaic sediments and loess, massive ice bodies occurred. A pingo developed where the deltaic sediments reached the surface. On hillslopes, suspended cryostructure on solifluction sheets indicates quasi‐syngenetic permafrost aggradation; lobes, in contrast, were ice‐poor. Suspended cryostructure in eluvial deposits reflects epigenetic or quasi‐syngenetic permafrost formation on a weathered bedrock plateau. Landform‐scale spatial variations in ground ice and carbon relate to variations in slope, sedimentation rate, moisture conditions and stratigraphy. Although the study reveals close links between Holocene landscape evolution and permafrost history, our results emphasize a large uncertainty in using terrain surface indicators to infer ground‐ice contents and upscale from core to landform scale in mountainous permafrost landscapes.

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“…; Christiansen ). The outer part of the gently sloping fan is covered by 1–2 m of loess (Bryant ), that thickens towards the river bank. The fan ends with a cliff 2–3 m high eroded by the river Adventelva into the north part of the fan.…”

Section: Study Areamentioning

confidence: 99%

Land cover classification using high‐resolution aerial photography in adventdalen, svalbard

Mora

Vieira

Pina

et al. 2015

Geografiska Annaler: Series A, Physical Geography

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A methodology was tested for high‐resolution mapping of vegetation and detailed geoecological patterns in the Arctic Tundra, based on aerial imagery from an unmanned aerial vehicle (visible wavelength – RGB, 6 cm pixel resolution) and from an aircraft (visible and near infrared, 20 cm pixel resolution). The scenes were fused at 10 and 20 cm to evaluate their applicability for vegetation mapping in an alluvial fan in Adventdalen, Svalbard. Ground‐truthing was used to create training and accuracy evaluation sets. Supervised classification tests were conducted with different band sets, including the original and derived ones, such as NDVI and principal component analysis bands. The fusion of all original bands at 10 cm resolution provided the best accuracies. The best classifier was systematically the maximum neighbourhood algorithm, with overall accuracies up to 84%. Mapped vegetation patterns reflect geoecological conditioning factors. The main limitation in the classification was differentiating between the classes graminea, moss and Salix, and moss, graminea and Salix, which showed spectral signature mixing. Silty‐clay surfaces are probably overestimated in the south part of the study area due to microscale shadowing effects. The results distinguished vegetation zones according to a general gradient of ecological limiting factors and show that VIS+NIR high‐resolution imagery are excellent tools for identifying the main vegetation groups within the lowland fan study site of Adventdalen, but do not allow for detailed discrimination between species.

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Loess deposits In Lower Adventdalen, Spitsbergen

Cited by 20 publications

References 4 publications

Soil Physical and Environmental Conditions Controlling Patterned-Ground Variability at a Continuous Permafrost Site, Svalbard

Soil Physical and Environmental Conditions Controlling Patterned-Ground Variability at a Continuous Permafrost Site, Svalbard

Holocene permafrost history and cryostratigraphy in the High‐Arctic Adventdalen Valley, central Svalbard

Land cover classification using high‐resolution aerial photography in adventdalen, svalbard

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