DOI: 10.1016/j.quascirev.2015.09.004
Scopus记录号: 2-s2.0-84941285973
论文题名: Repeated Holocene rock avalanches onto the Brenva Glacier, Mont Blanc massif, Italy: A chronology
作者: Deline P. ; Akçar N. ; Ivy-Ochs S. ; Kubik P.W.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2015
卷: 126 起始页码: 186
结束页码: 200
语种: 英语
英文关键词: 10Be
; Glacier
; Historical sources
; Holocene
; Moraine
; Permafrost
; Radiocarbon dating
; Rock avalanche
; Surface exposure dating
Scopus关键词: Glaciers
; Landforms
; Permafrost
; Holocenes
; Moraine
; Radiocarbon dating
; Rock avalanche
; Surface exposure dating
; Rocks
; chronology
; cosmogenic radionuclide
; geomorphology
; glacier
; historical record
; Holocene
; moraine
; mountain environment
; permafrost
; radiocarbon dating
; rock avalanche
; valley
; Brenva Glacier
; Italy
; Valle d'Aosta
英文摘要: Infrequent rock avalanches (volume ≥1 Mm3) are long-runout processes, especially when travelling onto a glacier, that may threaten populated mountain valleys. Rock avalanches also have strong implications are for relief generation and destruction though time. Both consequences make reconstruction and dating of past events crucial, but dense clusters of events documented in one basin that may improve our knowledge of rock-avalanche frequency and triggering are very rare. Here we propose a chronology of seven of the rock-ice avalanches that affected a steep glacier basin on the southeast side of the Mont Blanc during the late Holocene. A geomorphological study of the runout deposits on the valley floor and the opposite side was combined with the analysis of historical sources and the use of absolute and relative dating methods, especially surface exposure dating with cosmogenic nuclides of 18 granite boulders from two deposits.These rock-ice avalanches are dated AD 1997 and 1920, with a rock volume in the range 2.4-3.6 and 2 × 106 m3, respectively; AD 1767, with a slightly shorter runout; AD 1000-1200, with a longer runout; c. AD 500, the runout of which is uncertain; c. 2500 BP, the determination of which is indirect; and c. 3500 years, with the longest runout.There is no distinct relationship between climatic periods and occurrence of these rock avalanches. Even for the two best documented ones, modelling suggests that the 1997 scar was characterized by a permafrost close to 0 °C, whereas in contrast, the 1920 scar was on the contrary located in cold permafrost. © 2015 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59816
Appears in Collections: 过去全球变化的重建
There are no files associated with this item.
作者单位: EDYTEM Lab, Université de Savoie, CNRS, Le Bourget-du-Lac, France; University of Bern, Institute of Geological Sciences, Baltzerstrasse 1-3, Bern, Switzerland; Laboratory of Ion Beam Physics, ETH Hönggerberg, Zürich, Switzerland
Recommended Citation:
Deline P.,Akçar N.,Ivy-Ochs S.,et al. Repeated Holocene rock avalanches onto the Brenva Glacier, Mont Blanc massif, Italy: A chronology[J]. Quaternary Science Reviews,2015-01-01,126