Glacial-topographic interactions in the Teton Range, Wyoming

TitleGlacial-topographic interactions in the Teton Range, Wyoming
Publication TypeJournal Article
Year of Publication2010
AuthorsFoster D, Brocklehurst SH, Gawthorpe RL
JournalJournal of Geophysical Research-Earth Surface
Date PublishedFeb 17
ISBN Number0148-0227
Accession NumberWOS:000274789800001

Understanding interactions among tectonics, topography, climate, and erosion is fundamental to studies of mountainous landscapes. Here, we combine topographic analyses with modeled distributions of precipitation, insolation, and flexural isostasy to present a conceptual model of topographic evolution in the Teton Range, Wyoming, and test whether efficient glacial relief production has contributed to summit elevations. The conceptual model reveals a high degree of complexity inherent in even a relatively small, glaciated, mountain range. Back tilting has caused topographic asymmetry, with the greatest relief characterizing eastern catchments in the center of the range. Two high summits, Grand Teton and Mount Moran, rise hundreds of meters above the surrounding landscape; their elevations set by the threshold hillslope angle and the spacing between valleys hosting large, erosionally efficient glaciers. Only basins >20 km2 held glaciers capable of eroding sufficiently rapidly to incise deeply and maintain shallow downvalley gradients on the eastern range flank. Glacial erosion here was promoted by (1) prevailing westerly winds transporting snow to high-relief eastern basins, leading to cross-range precipitation asymmetry; (2) the wind-blown redistribution of snow from open western headwaters into sheltered eastern cirques, with the associated erosion-driven migration of the drainage divide increasing eastern accumulation areas; and (3) tall, steep hillslopes providing shading, snow influx from avalanching, and insulating debris cover from rockfalls to valley floor glaciers. In comparison, the topographic enhancement of glacial erosion was less pronounced in western, and smaller eastern, basins. Despite dramatic relief production, insufficient rock mass is removed from the Teton Range to isostatically raise summit elevations.

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