First observations on needle ice formation in the sub-Antarctic

Nel, Werner; Boelhouwers, Jan

doi:10.1017/s0954102013000722

Cited by 5 publications

(7 citation statements)

References 11 publications

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“…The vertical shift of the subsurface sensors was restricted using a fixed wooden slab from which only the tips of the sensor were extruded into the soil. This is in line with what previous studies suggested (Grab, 2001; Li, Matsuoka, & Niu, 2018; Nel & Boelhouwers, 2014; Yamagishi & Matsuoka, 2015). Moreover, 5 temporally randomized soil samples (between 09:00 and 13:00 local time) were collected at 0–2 cm of depth at each plot to assess and compare the gravimetric water content (WC) variability among the quadrats.…”

Section: Methodssupporting

confidence: 93%

Section: Experimental Setup: Thermistors and Bendingsupporting

confidence: 93%

“…Our intra‐plot and multi‐temporal data demonstrate that the surface spatial variability of WCRs and needle ice length match. Indeed, relatively high (−0.49 to 0.10°C h −1 ) surface WCRs are needed to form needle ice (Lawler, 1993; Nel & Boelhouwers, 2014) but not extremely high, otherwise ice lenses form (Branson, 1992; Higashi, 1958). On the other hand, lower surface WCRs (−0.12 to −0.18°C h −1 ) maintain a continuous accretion once formed (visible at the surface) (Figure 5).…”

Section: Discussionmentioning

confidence: 99%

“…It is for this reason that the climatic control on periglacial soil processes needs to be analyzed (Matsuoka, 2011). Needle ice phenomenon is widespread worldwide, for instance, Maritime Subantarctica (Boelhouwers, Holness, & Sumner, 2003; Haussmann, Boelhouwers, & Mcgeoch, 2009; Holness, 2004; Nel & Boelhouwers, 2014), the United Kingdom (Ballantyne, 1996), Alaska (Gartner, Chapin Iii, & Shaver, 1986), South Africa (Grab, 2001, 2002), Canada (Mackay & Mathews, 1974), Japan (Matsuoka, 1998b, 1998a) and Austria (Kellerer‐Pirklbauer, 2018).…”

Section: Introductionmentioning

confidence: 99%

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Advances in understanding the cooling rates and bending of needle ice: Photogrammetric and thermal observations leading to the spatial distribution of needle ice creep

Ponti

Guglielmin

2023

Earth Surf Processes Landf

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The freeze–thaw cycles are a process that dominate entire landscapes with different intensity and magnitudes that are strongly changing in the current climate change conditions. In particular, the diurnal frost heave (FH) and needle ice creep (NIC) are two poorly studied processes, especially in the field, despite their effects on the sediment transportation and vegetation colonization on Alpine slopes. In a site of the Central Alps, we applied photogrammetry, thermal imaging, manual measurements and thermistors logging to improve the knowledge of the driving parameter for the formation and accretion of needle ice, of the relations of their spatial distribution with cooling rates and the frost creep modelling change in the presence of the bending process. Among the driving factors, we demonstrate that very local conditions govern the development of the needle ice, like the air cooling rates, the deepening of the freezing front and the surficial cooling rates. Especially low cooling rates are necessary for an intense process. Also the grain size influences the development of the needle ice with higher needle ice development under fine sediment than under small clasts due to a differential thermal conductivity. Moreover, the bending of needle ice has proved to be dependent on its length, age and type of heaved sediment. Therefore, potential frost creep formulas needed to be ameliorated considering the bending angle. Subsequently, a question about the role of slope gradient in NIC is treated.

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Section: Methodssupporting

confidence: 93%

Section: Experimental Setup: Thermistors and Bendingsupporting

confidence: 93%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Advances in understanding the cooling rates and bending of needle ice: Photogrammetric and thermal observations leading to the spatial distribution of needle ice creep

Ponti

Guglielmin

2023

Earth Surf Processes Landf

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“…Warmer air temperatures will also modify ground thermal dynamics, which could impact the frequency and magnitude of needle ice growth, the freezing depths of both diurnal and seasonal frost and sediment movement and cycling. Needle ice formation is a very important diurnal soil frost process across most islands (Nel et al 2021), impacting several keystone species and small-scale geomorphic processes in the fellfield habitat (Nel & Boelhouwers 2014). Transported propagules of invasive plant species have been shown to have increased rates of establishment and range expansion in the terrestrial habitats of the sub-Antarctic (Convey 2020).…”

mentioning

confidence: 99%