کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4687416 1635591 2006 22 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Allometric development of glacial cirque form: Geological, relief and regional effects on the cirques of Wales
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Allometric development of glacial cirque form: Geological, relief and regional effects on the cirques of Wales
چکیده انگلیسی

Headward and downward erosion near glacier sources, at rates exceeding fluvial erosion, is important in recent discussions of orogen development and the limits to relief. This relates to a long history of debate on how the form of glacial cirques develops, which can be advanced by relating shape to size in large data sets. For 260 cirques in Wales, this confirms different rates of enlargement in the three dimensions: faster in length than in width, and slower in vertical dimension whether expressed as overall height range, axial height range or wall height. Maximum gradient, plan closure and number of cols increase with overall size. This allometric development applies over different cirque types, regions and rock types. Headwall retreat, often by collapse following glacial erosion at the base, is faster than downward erosion. Welsh cirques form a scale-specific population and, as in other regions, size variables follow Gaussian distributions on a logarithmic scale. As in England, width commonly exceeds length. Vertical dimensions correlate with length more than with width. Cirque form varies with geology, but also with relief as both vary between mountain groups. The main contrast is between larger, better-developed cirques and higher relief on volcanic rocks in the north-west, and smaller, less-developed cirques and lower relief on sedimentary rocks in the south.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Geomorphology - Volume 80, Issues 3–4, 30 October 2006, Pages 245–266
نویسندگان
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