Multidisciplinary Investigations of Alpine Ice Patches in Southwest Yukon, Canada: Paleoenvironmental and Paleobiological Investigations

Abstract

ABSTRACT. Since the discovery of dung-rich alpine ice patches in southwest Yukon in 1997, continuing multidisciplinary studies have provided a unique window on the biology, climate, and hunting activity in this region over much of the Holocene. Aerial surveys have identified 72 ice patches of variable size, and 65 patches have been ground-surveyed for organic remains. Of these, 35 yielded an abundance of biological specimens, including caribou and other rare large mammal remains, mummified small mammals and birds, and artifacts spanning 8000 years. The dung provides pollen and plant macrofossils for analysis and paleoenvironmental reconstruction, as well as dietary, genetic, and parasitic information. Stratigraphically controlled sampling of dung within ice layers has yielded a geochronology placing their formation as early as 8300 to 8000 years BP. Ice patch formation was nearly continuous except for an interval between 6700 and 4700 years BP and another between 1440 and 1030, when warm or dry conditions (or both) resulted in no net ice accumulation. Resumption of ice accumulation over the following 500 years likely culminated in the Little Ice Age. The size of the ice patches during this period is made evident by a lichen-free zone that haloes each patch. More recently, interpretation of air photos from 1946 to 2001 has found a significant reduction in ice patch dimensions. Daily temperature records for Whitehorse (1942 -2001) were used to calculate melting degree-day values that account for a large part of the variation in ice patch size, indicating that while considerable melting has likely occurred since the end of the Little Ice Age, the ice patches are highly sensitive to decadal changes in temperature.

New Aspects of High-Mountain Palaeobiogeography: A Synthesis of Data from Forefields of Receding Glaciers and Ice Patches in the Tärna and Kebnekaise Mountains, Swedish Lapland

“…In many parts of the world, recent glacier recession has opened an entirely new window on the palaeoecology, vegetation history, and archaeology of sites at high elevations (Dyurgerov and Meier, 2000;Farnell et al, 2004;Dove et al, 2005;Nesje, 2009;Menounos et al, 2009;Nesje et al, 2011;Andrews and MacKay, 2012;Callanan, 2012). In forefields of mountain glaciers and perennial snow and ice patches, in most cases quite close to the tree line, exposure of megafossil tree remnants of different species spanning major parts of the Holocene is quite common (e.g., Nicolussi and Patzelt, 2000;Hormes et al, 2001;Schlüchter and Jörin, 2004;Koch et al, 2007;Benedict et al, 2008;Joerin et al, 2008;Wiles et al, 2008;Scapozza et al, 2010;Koehler and Smith, 2011;Nicolussi and Schlüchter, 2012).…”

Identification of Ancient Feather Fragments Found in Melting Alpine Ice Patches in Southern Yukon

“…The presence of whole birds (Krajick, 2002), feathers, and feather fletchings (the attachment of feathers to arrows) associated with the wooden weapon shafts recovered from these ice patches became apparent as soon as scientists began examining the materials (Kuzyk et al, 1999;Krajick, 2002;Farnell et al, 2004). Because it is possible to identify birds from archaeological feather fragments and microscopic analysis (Hargrave, 1965;Messinger, 1965;Dove, 1998;Dove and Peurach, 2002;Rogers et al, 2002), we examined some of the feathers directly attached to or associated with these artifacts in order to document the species of birds used by these ancient peoples.…”

Frozen: The Potential and Pitfalls of Ground-Penetrating Radar for Archaeology in the Alaskan Arctic

“…The significance of ice patch finds stems from their ability to provide unique insights into prehistoric cultural developments and technology since these perishable items are rare in the vast majority of archaeological contexts. These same deposits often also contain rich assemblages of well-preserved plant and animal remains that can shed light on long-term environmental change [51]. There is an urgency to learn about these unique frozen archives because, across broad areas of the globe, glaciers and alpine ice patches are melting at a rate not seen for hundreds or thousands of years [52].…”