Detection of Ice Wedge Cracking in Permafrost Using Miniature Accelerometers

Abstract

Determining the exact timing of ice wedge cracking in permafrost is challenging. Five miniature accelerometers were installed near the ground surface in the trough of a primary ice wedge within a network of low‐centered polygons in Adventdalen, Svalbard, to test whether these instruments could be used to detect dynamics of thermal contraction cracking. Data from 2003 to 2013 were analyzed to characterize cryoseismic signals in the ice wedge trough. High‐magnitude accelerations (from 5 g to at least 100 g) were typically registered in late winter, when the top of permafrost had cooled to about −10°C; these likely correspond to ice wedge cracking in permafrost. Tensile stresses calculated from temperatures measured in the ice wedge trough are near laboratory strengths reported for ice and mineral active layer sediments, supporting the interpretation that large accelerations are caused by thermal contraction cracking. Lower magnitude accelerations occurred throughout the freezing season, usually coinciding with rapid cooling at the ground surface. These small accelerations may be associated with (i) the initiation of small cracks in the active layer of the trough or (ii) the horizontal and vertical propagation of existing ice wedge cracks. The results of this investigation indicate that miniature accelerometers are an effective, inexpensive, and simple method to determine the timing of ice wedge cracking and rates of crack propagation along ice wedge troughs.

Ice wedges as archives of winter paleoclimate: A review

“…This could be supported by field manipulation experiments such as installing appropriate sampling devices in artificial cracks to collect samples of newly formed ice veins at different depths and at different times of crack infilling. Monitoring of frost‐crack timing using shock loggers (accelerometers) or breaking cables (eg,) should be combined with measurements of air and ground temperatures as well as snow thickness, even though breaking cables do not provide information on subsequent events such as crack widening or secondary cracking. This would help to detect the threshold conditions for frost cracking at specific sites and to assess seasonal patterns as well as the temporal frequency of precipitation, frost cracking and infilling events.…”

Air temperature measurements using autonomous self-recording dataloggers in mountainous and snow covered areas

“…Autonomous self-recording and price competitive temperature loggers are widely used in research in areas involving building construction (Fang et al, 2014), animal biology (Schofield et al, 2009), and vegetation (Brabyn et al, 2014;Measham et al, 2017), and also in climatic-meteorological applications (Domínguez-Villar et al, 2015;Imholt et al, 2013;Juliussen and Humlum, 2007;Lundquist and Lott, 2008;O'Neill and Christiansen, 2018). In the present study temperature measurements were made using three thermistor types: Thies PT100, Tinytag-Plus-2 (Tinytag), and Thermochron iButton (iButton).…”

Viscoelastic Modeling of Nocturnal Thermal Fracturing in a Himalayan Debris‐Covered Glacier

“…These examples suggest that significant thermal cracking only occurs when the surface temperatures are below −30 °C. Major ice‐wedge cracking in permafrost preferentially occurs when the surface temperature is below −20 °C, with these warmer conditions potentially corresponding to weaker wedge ice, which is known to contain sediment inclusions, bubbles, and foliations (Matsuoka et al, ; O'Neill & Christiansen, ). Acoustic ambient noise observed beneath the shore‐fast ice in the Arctic was found to be controlled by the air temperature (Milne et al, ).…”

“…Thermal strains induce near-surface thermal stresses, which are recognized as an important agent in various processes. For example, the thermal stress in ice cover is important for dam design (Petrich et al, 2015), can cause large-scale fractures in sea ice (Bazant, 1992;Evans & Untersteiner, 1971;Lewis, 1994;Xie & Farmer, 1991) and lake ice (Carmichael et al, 2012), is responsible for polygon formation in permafrost Journal of Geophysical Research: Earth Surface 10.1029/2018JF004848 on Earth and Mars (Lachenbruch, 1962;Levy et al, 2009;Mellon, 1997;O'Neill & Christiansen, 2018), and is suggested to be an important erosion process on cometary surfaces and the Moon (e.g., Attree et al, 2017). Sanderson (1978) conducted analytic investigations of thermal stresses near glacial surfaces and concluded that (i) in the upper 3 m of the ice, thermal stresses dominate those originating from the overburden pressure and from the gross deformation; (ii) tensile fracture cannot develop in pure ice due to its high tensile strength, unless assisted by stress concentrations at heterogeneities; and (iii) such fractures are more likely to form in weaker firn and snow.…”