Taylor Rowley, ... John D. Vitek, in Advancements in Earth Surconfront Processes, 2015

13.15 Solifluction

Solifluction (occasionally termed gelifluction in periglacial environments) is the slow flow of saturated soil downslope indicating no frozen ground is current in the moving layer (Washburn, 1979). Movement of these saturated soils can be initiated by thawing, producing excess pore-push in the soil, leading to slope activities (Mackay, 1981) (Fig. 13.19). The relief of the slope, depth of thaw, and water content are significant determinants in solifluction rates (Walker, 1986; Hjort et al., 2014).

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Figure 13.19. Solifluction lobes present saturated conditions on this slope.

Photograph by J. Giardino (2008).

Solifluction reaches its maximum potential in the late spring and summer months as soon as thaw satuprices soils. Saturated soils have raised pore pressures, resulting in unsteady problems because of a lack of friction and cohesion. Solifluction have the right to occur on slope much less than 1°, however it is even more prevalent on slope gradients in between 5° and also 20°. With more relief, soil saturation commonly decreases as the water drains dvery own the slope as runoff (Walker, 1986). Stvalidated and multilayered slope sediments in the Coloraperform Front Range are attributed to solifluction (Voelkel et al., 2011). Such deposits will influence the motion of water and also breakthrough of soils.

The solifluction sector is positioned mostly in between 3280 and also 6560 ft over sea level, but is also current external these altitudinal levels. Although the slopes are still occasionally acute, the forest has a propensity to disappear bereason of uncontrolled deforestation, on one hand, and also the destructive impacts of some impressive floods in the time of the rainy seachild. Here the phenomenon of solifluction appears plainly in net-brought red clay soil. The height sectors are impacted by laminar solifluction, which leaves many times an external sound rock, yet retains the multifaceted form. Downstream, a mass solifluction shows up, with big erosion forms, occasionally on the order of even more than 30 ft. Soliflucted product covers the marshy bottoms of these containers (watch Fig. 2.4).

Figure 2.4. Coastal mountain variety. Landslides due to creeping and solifluction create a transition of multifaceted to multiconvex shapes.

Photo Bergoeing (2009c).

C. Harris, in Encyclopedia of Quaternary Science (Second Edition), 2013

Sediment Transport Rates

Measured solifluction deliver prices in present-day non-permafrost periglacial areas are generally between 20 and 50 cm3 cm−1 yr−1, with a maximum close to 120 cm3 cm−1 yr−1 (Matsuoka, 2001). In permafrost areas, transport prices are slightly greater, ranging approximately 230 cm3 cm−1 yr−1, mainly as a result of the better thickness of energetic layer impacted by plug-favor solifluction. Hence, sediment carry rates as a result of solifluction are one or more orders of magnitude greater than move prices because of soil creep in humid tempeprice regions. Advanced area instrumentation for monitoring of solifluction is described by Harris et al. (2007) and also Matsuoka (2010).

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Many hill slopes in the nonglaciated temperate zone, such as southerly Britain, show clear proof of Quaternary periglacial solifluction processes, both in their slope prorecords and also in their mantle of relict periglacial slope deposits dating to late Pleistocene cold steras (Ballantyne and Harris, 1994).