کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6431994 1635403 2015 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Glacier change from the early Little Ice Age to 2005 in the Torngat Mountains, northern Labrador, Canada
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Glacier change from the early Little Ice Age to 2005 in the Torngat Mountains, northern Labrador, Canada
چکیده انگلیسی


- Field and remote sensing data used to estimate Neoglacial Torngat glacier margins
- Approximately 53% of glacier ice has been lost since maximum Neoglacial extents.
- Direct lichenometric dating suggests Neoglacial maximum s between A.D. 1581-1673.
- Total change since Little Ice Age similar to other areas with small alpine glaciers

The glaciers of the Torngat Mountains of northern Labrador are the southernmost of the Canadian Arctic and the easternmost of continental North America. Currently, 195 small mountain glaciers cover an area in excess of ~ 24 km2, confined mostly to small cirques and upland depressions. Using a combination of field and remote sensing methods this study reconstructs and dates the areal extent of Torngat glaciers at their Neoglacial maximums, enabling the first assessment of regional glacier change over the past several centuries. Mapped glacier paleomargins (n = 165) are compared to current (2005) glaciers and ice masses, showing a 52.5% reduction in glacier area, with at least 11 former glaciers altogether disappearing. Glacier change is spatially homogenous and independent of most geographic and topographic factors; however, glacier elevation and glacier size mitigated total change. Previously established lichen growth stations were revisited, and growth rates recalculated based on ~ 30-year-long records, enabling the construction of locally derived low- and high-altitude lichen growth curves. Using growth rates and in situ lichen measurements, the retreat from maximum Neoglacial moraine extents are suggested to have occurred between A.D. 1581 and 1673. These findings indicate a similar magnitude of post-LIA retreat to mountain glaciers elsewhere, yet a much earlier timing (~ 200 years) of retreat than other glaciers in the eastern Canadian Arctic. Though no definitive answer explaining this discrepancy is presented, evidence suggests that regional climate dynamics and the importance of solar radiation for Torngat glaciers may play an important role in local glacierization.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Geomorphology - Volume 246, 1 October 2015, Pages 558-569
نویسندگان
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