Talus-and-gorge ice caves in the northeastern United States past to present—A microclimatological study

Abstract

The focus of this article is both a region and a type of cave not typically associated with ice caves. Nevertheless, both the region and the type play an important role in American ice-cave research. Talus-and-gorge ice caves in the northeastern United States can be used as climate indicators for a whole region; and therefore, they are the target of this young field of research. Ice caves, in general, are sensitive climatopes that can serve as excellent indicators for short and long term changes in the climate of a region, principally because of shifts between phases of increasing ice growth and melting during a year and over time. This research started with an investigation of known talus-and-gorge ice caves, followed by environmental monitoring of selected caves with perennial ice that were equipped with temperature sensors recorded over four years. This is one of the world's longest high-resolution climatologic monitoring record of such caves. In addition, the height of the ice was surveyed annually at a time when ice would most likely be at its minimum, the start of November. This allowed for investigation of the annual changes and the influence of the temperature over the previous year. Some predictions for the future of the ice caves and the whole region could be deduced from the data. At the moment, there is no sign of either a renewed increase in the number of talus-and-gorge ice caves or an increase in ice accumulation within the existing ones.D. Holmgren, A. Pflitsch, K. Rancourt, and J. Ringeis. Talus-and-gorge ice caves in the northeastern United States past to present-A microclimatological study.

Is that a relict rock glacier?

“…Mean and absolute temperature observed at the RRG's front (Figs. 6 and 7) are largely consistent with previous studies in the Alps on talus slopes (e.g., Delaloye and Lambiel, 2005;Popescu et al, 2017) and rock glaciers (e.g., Delaloye and Lambiel, 2005;Morard et al, 2008), as well as in talus-and-gorge ice caves in North America (Holmgren et al, 2017).…”

Talus and its cooling effects on the thermal regime of permafrost: A review

“…89 Additionally, the spatial distribution of snow thickness is not necessarily uniform, possibly being thicker at the bottom and becoming progressively thinner towards the top. 72 The presence of permafrost (e.g., 15,42,64,70,109 ), ground ice (e.g., 71,96,110,111 ), or groundwater (e.g., 82,[112][113][114] ) in talus increases the local thermal conductivity, thereby facilitating heat transfer within the talus. Permafrost is generally distributed at the base of the talus, 16,17,53,62,72,78,115 but can also exist at the top at high altitude.…”

Thermal Regime of Two Talus Slopes in Northwestern Ontario

“…The study area in Northwestern Ontario is different from these regions because neither is it far enough north, nor are the mesas and cuestas sufficiently elevated to result in T a less than 0℃. T a in the region ranges between 2.5℃ at Thunder Bay and which are similar to or lower than locations where permafrost has been found in blocky materials (Delaloye & Reynard, 2001;Gude et al, 2003;Gorbunov et al, 2004;Holmgren et al, 2017a).…”

“…In Balch's observation, the displacement of warm air tends to be much more rapid than that of cold air. Cold air remains longest where there is an obstacle to be overcome (a lip) in order for it to drain away (Balch, 1900;Holmgren et al, 2017a). This creates pockets of long-lasting low temperature which, combined with a water supply, may create and preserve ice in the lowest parts of the cave or blocky materials (Balch, 1900).…”

“…The formation of ice has been mainly attributed to percolation and refreezing of meltwater during snowmelt (Balch, 1900;Ohata et al, 1994;Zacharda et al, 2007) (Fig. 5.1 Kneisel et al, 2015), and may also have restricted convection by filling or covering up holes between the blocks (Holmgren et al, 2017a).…”