干旱区生态环境知识资源中心(Arid): Sediment sources and transport by the Kahiltna Glacier and other catchments along the south side of the Alaska Range, Alaska

Arid

DOI	10.1130/GES02190.1
	Sediment sources and transport by the Kahiltna Glacier and other catchments along the south side of the Alaska Range, Alaska
	Matmon, Ari 1; Haeussler, P. J.2
通讯作者	Matmon, Ari
来源期刊	GEOSPHERE
ISSN	1553-040X
出版年	2020
卷号	16 期号:3 页码:787-805
英文摘要	Erosion related to glacial activity produces enormous amounts of sediment. However, sediment mobilization in glacial systems is extremely complex. Sediment is derived from headwalls, slopes along the margins of glaciers, and basal erosion; however, the rates and relative contributions of each are unknown. To test and quantify conceptual models for sediment generation and transport in a simple valley glacier system, we collected samples for Be-10 analysis from the Kahiltna Glacier, which flows off Denali, the tallest mountain in North America. We collected angular quartz clasts on bedrock ledges from a high mountainside above the equilibrium line altitude (ELA), amalgamated clast samples from medial moraines, and sand samples from the river below the glacier. We also collected sand from nine other rivers along the south flank of the Alaska Range. In the upper catchment of the Kahiltna drainage system, toppling, rockfall, and slab collapse are significant erosional processes. Erosion rates of hundreds of millimeters per thousand years were calculated from Be-10 concentrations. The Be-10 concentrations in amalgamated samples from medial moraines showed concentrations much lower than those measured from the high mountainside, a result of the incorporation of thick, and effectively unexposed, blocks into the moraine, as well as the incorporation of material from lower-elevation nearby slopes above the moraines. The Be-10 sediment samples from downstream of the Kahiltna Glacier terminus showed decreasing concentrations with increasing distance from the moraine, indicating the incorporation of material that was less exposed to cosmic rays, most likely from the glacier base as well as from slopes downstream of the glacier. Taken together, Be-10 concentrations in various samples from the Kahiltna drainage system indicated erosion rates of hundreds of millimeters per thousand years, which is typical of tectonically active terrains. We also measured Be-10 concentrations from river sediment samples collected from across the south flank of the Alaska Range. Calculation of basinwide weighted erosion rates that incorporated hypsometric curves produced unrealistically high erosion rates, which indicates that the major source of sediment was not exposed to cosmic rays and was primarily derived from the base of glaciers. Moreover, the apparently high erosion rates suggest that parts of each drainage system are not in erosional steady state with respect to cosmogenic isotope accumulation.
类型	Article
语种	英语
国家	Israel ; USA ; France
开放获取类型	Green Published, gold
收录类别	SCI-E
WOS记录号	WOS:000537454500005
WOS关键词	BE-10-DERIVED EROSION RATES ; DOMINATED MEDIAL MORAINES ; DENALI-FAULT-SYSTEM ; COSMOGENIC BE-10 ; EASTERN ; SURFACES ; DESERT ; BASIN ; DENUDATION ; FEEDBACKS
WOS类目	Geosciences, Multidisciplinary
WOS研究方向	Geology
来源机构	United States Geological Survey ; French National Research Institute for Sustainable Development ; Hebrew University of Jerusalem
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/318735
作者单位	1.Hebrew Univ Jerusalem, Inst Earth Sci, IL-91904 Jerusalem, Israel; 2.US Geol Survey, 4210 Univ Dr, Anchorage, AK 99508 USA; 3.Aix Marseille Univ, CNRS, Ctr Rech & Enseignement Geosci Environm CEREGE, UMR 6635, BP 80, F-13545 Aix En Provence 4, France
推荐引用方式 GB/T 7714	Matmon, Ari,Haeussler, P. J.. Sediment sources and transport by the Kahiltna Glacier and other catchments along the south side of the Alaska Range, Alaska[J]. United States Geological Survey, French National Research Institute for Sustainable Development, Hebrew University of Jerusalem,2020,16(3):787-805.
APA	Matmon, Ari,&Haeussler, P. J..(2020).Sediment sources and transport by the Kahiltna Glacier and other catchments along the south side of the Alaska Range, Alaska.GEOSPHERE,16(3),787-805.
MLA	Matmon, Ari,et al."Sediment sources and transport by the Kahiltna Glacier and other catchments along the south side of the Alaska Range, Alaska".GEOSPHERE 16.3(2020):787-805.