کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4684992 1635463 2013 14 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A regional inventory of rock glaciers and protalus ramparts in the central Italian Alps
ترجمه فارسی عنوان
موجودی منطقه ای از یخچال های سنگی و معادن پرولتالی در آلپ مرکزی ایتالیا
کلمات کلیدی
یخچال های سنگی پرولتالس رمپ، فهرست، مقیاس منطقه ای، ویژگی های توپوگرافی، بارش
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
چکیده انگلیسی

We present a regional inventory of rock glaciers (n = 1514) and protalus ramparts (228) for the Lombardy region, central Italian Alps. To identify and classify the landforms we inspect three sequential air-orthophoto mosaics and a 2 m-DSM, and conduct confirmatory field work. The inventory forms an empirical basis to analyze: (i) the relative contribution of hillslope (i.e., talus slopes) and glacial (i.e., moraines) sediment stores to rock glacier sediment supply; (ii) linkages between the landforms inventoried and local topographic attributes; (iii) the spatial variability of periglacial activity in relation to a parsimonious set of environmental variables (i.e., elevation, precipitation, and lithology); and (iv) the effects of the Pleistocene–Holocene climatic transition on the distribution of intact and relict landforms. This analysis reveals that the elevation of rock glacier termini can vary over 200 m as a function of slope aspect. In turn, the distribution of rock glaciers among aspect categories is controlled by the structure of the valley network that promotes NW and SE exposures. Talus rock glaciers prevail numerically over the glacier-related typology, even though the latter population appears to have increased during the Holocene. Relict and intact rock glaciers have distinct spatial patterns in that the former display, on average, a 400-m elevation drop and a less clustered distribution towards northern aspects, suggesting that they have developed in more “permafrost-prone” climatic conditions. Analyzing the study region through a 27.5 km-grid has been instrumental for showing that the rock glacier specific area and terminus elevation are: (i) positively correlated with terrain elevation; and (ii) negatively correlated with mean annual precipitation. As a consequence, in relation to Holocene generalized atmospheric temperature rise, intact rock glaciers have progressively disappeared from the wetter and milder portions of the central Italian Alps. Analysis of rock glacier occurrence across litho-tectonic sectors does not provide conclusive dependences and requires further analysis. This inventory, which represents a necessary preliminary step for modelling the spatial distribution of discontinuous permafrost at the regional scale, fills a critical geographic gap in the context of ongoing permafrost research in the European Alps (e.g., PermaNET).


► We compile a regional inventory of rock glaciers and protalus ramparts.
► We analyze landform location in relation to topography, precipitation, and lithology.
► We show strong interactions between landform aspect and elevation.
► Rock glacier elevation and specific area correlate with elevation and precipitation.
► Relict and intact rock glaciers display climate-driven spatial distributions.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Geomorphology - Volume 186, 15 March 2013, Pages 136–149
نویسندگان
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