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| Titel |
Surface kinematics of periglacial sorted circles using structure-from-motion technology |
| VerfasserIn |
A. Kääb, L. Girod, I. Berthling |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1994-0416
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| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 8, no. 3 ; Nr. 8, no. 3 (2014-06-11), S.1041-1056 |
| Datensatznummer |
250116165
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| Publikation (Nr.) |
 copernicus.org/tc-8-1041-2014.pdf |
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| Zusammenfassung |
| Sorted soil circles are a form of periglacial patterned ground that is
commonly noted for its striking geometric regularity. They consist of an
inner fine domain bordered by gravel rings that rise some decimetres above
the fine domain. Field measurements and numerical modelling suggest that
these features develop from a convection-like circulation of soil in the
active layer of permafrost. The related cyclic burial and exhumation of
material is believed to play an important role in the soil carbon cycle of
high latitudes. The connection of sorted circles to permafrost conditions and
its changes over time make these ground forms potential palaeoclimatic
indicators. In this study, we apply for the first time photogrammetric
structure-from-motion technology (SfM) to large sets of overlapping
terrestrial photos taken in August 2007 and 2010 over three sorted circles at
Kvadehuksletta, western Spitsbergen. We retrieve repeat digital elevation
models (DEMs) and orthoimages with millimetre resolution and precision.
Changes in microrelief over the 3 yr are obtained from
DEM differencing and horizontal displacement fields from tracking features
between the orthoimages. In the fine domain, surface material moves radially
outward at horizontal rates of up to ~2 cm yr−1. The coarse
stones on the inner slopes of the gravel rings move radially inward at
similar rates. A number of substantial deviations from this overall radial
symmetry, both in horizontal displacements and in microrelief, shed new light
on the spatio-temporal evolution of sorted soil circles, and potentially of
periglacial patterned ground in general. |
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