ARTICLE SCIENTIFIQUE
An overcooled coarse-grained talus slope at low elevation:
New insights on air circulation and environmental impacts,
Cannon Cliff, New Hampshire, USA
AUTEURS
Daniel Germain | professeur - Département de géographie UQAM
Jean-François Milot | étudiante à la maîtrise - Département de géographie UQAM
Revue Earth Surface Processes and Landforms
No. 5; Avril 2024; 1-16 - https://doi.org/10.1002/esp.5792
Résumé (en anglais)
Overcooled talus slopes are generally described as islands of sporadic permafrost
below the lower alpine limit of permafrost. The negative thermal anomaly of the ground
is mainly consecutive to the internal ventilation of the deposit, but it is also conditioned
by multiple factors as topography, slope aspect and incline, openwork
structure and coarseness of the deposit, air temperature, solar radiation and wind
regime. Therefore, the study of the spatiotemporal dynamics of ventilation processes
allows a better understanding of the phenomenon. At Cannon Cliff, New Hampshire
(USA), several field visits and environmental monitoring allowed us to describe the
varying nature and significance of the ventilation mechanisms that can be observed
at the ground surface and associated with both the intensity and direction of the airflows
in a talus debris accumulation/protalus rampart system. The thermal negative
anomalies are strong enough to lower the ground temperature to the point of preserving
ice during the late spring and summer seasons. The monitoring of the gradient
between external (air) and internal (talus) temperatures coupled with several
dendroecological and geomorphological analyses provided a complete environmental
picture of the impacts, feedback and extent of the phenomenon.