气候变化领域集成服务门户(CCPortal): Be-10 systematics in the Tsangpo-Brahmaputra catchment: the cosmogenic nuclide legacy of the eastern Himalayan syntaxis

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DOI	10.5194/esurf-5-429-2017
	Be-10 systematics in the Tsangpo-Brahmaputra catchment: the cosmogenic nuclide legacy of the eastern Himalayan syntaxis
	Lupker, Maarten; Lave, Jerome; France-Lanord, Christian; Christl, Marcus; Bourles, Didier; Carcaillet, Julien; Maden, Colin; Wieler, Rainer; Rahman, Mustafizur; Bezbaruah, Devojit; Liu Xiaohan
通讯作者	Lupker, M (通讯作者)
发表日期	2017
ISSN	2196-6311
EISSN	2196-632X
起始页码	429
结束页码	449
卷号	5 期号:3
英文摘要	The Tsangpo-Brahmaputra River drains the eastern part of the Himalayan range and flows from the Tibetan Plateau through the eastern Himalayan syntaxis downstream to the Indo-Gangetic floodplain and the Bay of Bengal. As such, it is a unique natural laboratory to study how denudation and sediment production processes are transferred to river detrital signals. In this study, we present a new Be-10 data set to constrain denudation rates across the catchment and to quantify the impact of rapid erosion within the syntaxis region on cosmogenic nuclide budgets and signals. The measured Be-10 denudation rates span around 2 orders of magnitude across individual catchments (ranging from 0.03 to > 4 mm yr(-1)) and sharply increase as the Tsangpo-Brahmaputra flows across the eastern Himalaya. The increase in denudation rates, however, occurs similar to 150 km downstream of the Namche Barwa-Gyala Peri massif (NBGPm), an area which has been previously characterized by extremely high erosion and exhumation rates. We suggest that this downstream lag is mainly due to the physical abrasion of coarse-grained, low Be-10 concentration, landslide material produced within the syntaxis that dilutes the upstream high-concentration Be-10 flux from the Tibetan Plateau only after abrasion has transferred sediment to the studied sand fraction. A simple abrasion model produces typical lag distances of 50 to 150 km compatible with our observations. Abrasion effects reduce the spatial resolution over which denudation can be constrained in the eastern Himalayan syntaxis. In addition, we also highlight that denudation rate estimates are dependent on the sediment connectivity, storage, and quartz content of the upstream Tibetan Plateau part of the catchment, which tends to lead to an overestimation of downstream denudation rates. While no direct Be-10 denudation measurements were made in the syntaxis, the dilution of the upstream Be-10 signal, measured in Tsangpo-Brahmaputra sediments, provides constraints on the denudation rates in that region. These denudation estimates range from ca. 2 to 5 mm yr(-1) for the entire syntaxis and ca. 4 to 28 mm yr(-1) for the NBGPm, which is significantly higher than other large catchments. Overall, Be-10 concentrations measured at the outlet of the Tsangpo-Brahmaputra in Bangladesh suggest a sediment flux between 780 and 1430 Mt yr(-1) equivalent to a denudation rate between 0.7 and 1.2 mm yr(-1) for the entire catchment.
关键词	SITU-PRODUCED BE-10 NAMCHE-BARWA SYNTAXIS TERM EROSION RATES DENUDATION RATES TIBETAN PLATEAU SOUTHERN TIBET LANDSCAPE EVOLUTION ARUNACHAL HIMALAYA SEDIMENT DYNAMICS RAPID EXHUMATION
语种	英语
WOS研究方向	Physical Geography ; Geology
WOS类目	Geography, Physical ; Geosciences, Multidisciplinary
WOS记录号	WOS:000419312600001
来源期刊	EARTH SURFACE DYNAMICS
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/259101
推荐引用方式 GB/T 7714	Lupker, Maarten,Lave, Jerome,France-Lanord, Christian,et al. Be-10 systematics in the Tsangpo-Brahmaputra catchment: the cosmogenic nuclide legacy of the eastern Himalayan syntaxis[J]. 中国科学院青藏高原研究所,2017,5(3).
APA	Lupker, Maarten.,Lave, Jerome.,France-Lanord, Christian.,Christl, Marcus.,Bourles, Didier.,...&Liu Xiaohan.(2017).Be-10 systematics in the Tsangpo-Brahmaputra catchment: the cosmogenic nuclide legacy of the eastern Himalayan syntaxis.EARTH SURFACE DYNAMICS,5(3).
MLA	Lupker, Maarten,et al."Be-10 systematics in the Tsangpo-Brahmaputra catchment: the cosmogenic nuclide legacy of the eastern Himalayan syntaxis".EARTH SURFACE DYNAMICS 5.3(2017).