Dominance of tectonics over climate in Himalayan denudation

Godard, Vincent; Bourlès, Didier; Spinabella, Françoise; Burbank, Douglas W.; Bookhagen, Bodo; Fisher, G. Burch; Moulin, Adrien; Léanni, Laëtitia

doi:10.1130/g35342.1

Cited by 189 publications

(211 citation statements)

References 35 publications

Supporting

Mentioning

189

Contrasting

Unclassified

Order By: Relevance

“…This later estimate lies at the higher end of the previous estimates of denudation in the NBGPm, which range between 5 and 17 mm yr −1 (Stewart et al, 2008;Enkelmann et al, 2011;Larsen and Montgomery, 2012). These denudation rate estimates are also all significantly higher than other 10 Be denudation rates reported for other Himalayan catchments (Vance et al, 2003;Wobus et al, 2005;Finnegan et al, 2008;Lupker et al, 2012;Godard et al, 2012Godard et al, , 2014Puchol et al, 2014;Scherler et al, 2014;Le-Roux-Mallouf et al, 2015;Portenga et al, 2015;Morell et al, 2015;Olen et al, 2015Olen et al, , 2016Abrahami et al, 2016), highlighting the significance of the NBGPm as a denudational hot spot.…”

Section: Denudation Of the Eastern Syntaxis And Of The Nbgpmmentioning

confidence: 52%

See 1 more Smart Citation

<sup>10</sup>Be systematics in the Tsangpo-Brahmaputra catchment: the cosmogenic nuclide legacy of the eastern Himalayan syntaxis

Lupker¹,

Lavé²,

France‐Lanord

et al. 2017

Earth Surf. Dynam.

View full text Add to dashboard Cite

Abstract. 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 10 Be 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 10 Be 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 ∼ 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 10 Be concentration, landslide material produced within the syntaxis that dilutes the upstream high-concentration 10 Be 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 10 Be denudation measurements were made in the syntaxis, the dilution of the upstream 10 Be 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, 10 Be 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.

show abstract

Section: Denudation Of the Eastern Syntaxis And Of The Nbgpmmentioning

confidence: 52%

“…Constraining the magnitude of this overestimation requires an independent estimate of the sediment flux at the range outlet. Goswami et al (1985) reported a sediment flux of ca. 210 Mt yr −1 in Pasighat (pt.…”

Section: Denudation Of the Eastern Syntaxis And Of The Nbgpmmentioning

confidence: 99%

<sup>10</sup>Be systematics in the Tsangpo-Brahmaputra catchment: the cosmogenic nuclide legacy of the eastern Himalayan syntaxis

Lupker¹,

Lavé²,

France‐Lanord

et al. 2017

Earth Surf. Dynam.

View full text Add to dashboard Cite

show abstract

“…In tectonically active and previously glaciated mountain ranges there are three common orogenic processes that are most often suggested to dominate Holocene erosion rate patterns: climate gradients (Carretier et al, 2013;Olen et al, 2016), glacial modification of the landscape (Moon et al, 2011;Glotzbach et al, 2013), and patterns of tectonic rock uplift (Scherler et al, 2013;Godard et al, 2014;Adams et al, 2016). In the following we explore the relevance and applicability of these explanations to our dataset.…”

Section: Orogenic Processes Governing Erosion Ratesmentioning

confidence: 99%

Tectonic controls of Holocene erosion in a glaciated orogen

Adams

Ehlers

2018

Earth Surf. Dynam.

View full text Add to dashboard Cite

Abstract. Recent work has highlighted a strong, worldwide, alpine glacial impact on orogen erosion rates over the last 2 Ma. While it may be assumed that glaciers increased erosion rates when active, the degree to which past glaciations influence Holocene erosion rates through the adjustment of topography is not known. In this study, we investigate the influence of long-term tectonic and post-glacial topographic controls on erosion in a glaciated orogen: the Olympic Mountains, USA. We present 14 new 10 Be and 26 Al analyses which constrain Holocene erosion rates across the Olympic Mountains. Basin-averaged erosion rates scale with basin-averaged values of 5 km local relief, channel steepness, and hillslope angle throughout the range, similar to observations from non-glaciated orogens. These erosion rates are not related to mean annual precipitation or the marked change in Pleistocene alpine glacier size across the range, implying that glacier modification of topography and modern precipitation parameters do not exert strong controls on these rates. Rather, we find that despite spatial variations in glacial modification of topography, patterns of recent erosion are similar to those from estimates of long-term tectonic rock uplift. This is consistent with a tectonic model where erosion and rock uplift patterns are controlled by the deformation of the Cascadia subduction zone.

show abstract

“…While order-of-magnitude-higher precipitation amounts in the Himalayas do not allow for a clear picture of how climate defines landscape evolution (Godard et al, 2014), the much drier climate in the Pamirs provides fundamentally different boundary conditions and suggests water availability as a limiting factor (Fuchs et al, 2014b). Precipitation intensities alone, however, cannot solve the discrepancy of intensities between hillslope erosion and river incision in the Pamirs (Fuchs et al, 2014a, b).…”

Section: Introductionmentioning

confidence: 99%

Sensitivity analysis and implications for surface processes from a hydrological modelling approach in the Gunt catchment, high Pamir Mountains

et al. 2015

View full text Add to dashboard Cite

Abstract.A clear understanding of the hydrology is required to capture surface processes and potential inherent hazards in orogens. Complex climatic interactions control hydrological processes in high mountains that in their turn regulate the erosive forces shaping the relief. To unravel the hydrological cycle of a glaciated watershed (Gunt River) considered representative of the Pamir Mountains' hydrologic regime, we developed a remotesensing-based approach. At the boundary between two distinct climatic zones dominated by the Westerlies and Indian summer monsoon, the Pamir Mountains are poorly instrumented and only a few in situ meteorological and hydrological data are available. We adapted a suitable conceptual distributed hydrological model (J2000g). Interpolations of the few available in situ data are inadequate due to strong, relief-induced, spatial heterogeneities. Instead of these we use raster data, preferably from remote sensing sources depending on availability and validation. We evaluate remote-sensing-based precipitation and temperature products. MODIS MOD11 surface temperatures show good agreement with in situ data, perform better than other products, and represent a good proxy for air temperatures. For precipitation we tested remote sensing products as well as the HAR10 climate model data and the interpolation-based APHRODITE data set. All products show substantial differences both in intensity and seasonal distribution with in situ data. Despite low resolutions, the data sets are able to sustain high model efficiencies (NSE ≥ 0.85). In contrast to neighbouring regions in the Himalayas or the Hindu Kush, discharge is dominantly the product of snow and glacier melt, and thus temperature is the essential controlling factor. Eighty percent of annual precipitation is provided as snow in winter and spring contrasting peak discharges during summer. Hence, precipitation and discharge are negatively correlated and display complex hysteresis effects that allow for the effect of interannual climatic variability on river flow to be inferred. We infer the existence of two subsurface reservoirs. The groundwater reservoir (providing 40 % of annual discharge) recharges in spring and summer and releases slowly during autumn and winter, when it provides the only source for river discharge. A not fully constrained shallow reservoir with very rapid retention times buffers meltwaters during spring and summer. The negative glacier mass balance (−0.6 m w.e. yr −1 ) indicates glacier retreat, which will ultimately affect the currently 30 % contribution of glacier melt to annual stream flow. The spatiotemporal dependence of water release from snow and ice during the annual cycle likewise implies spatiotemporally restricted surface processes, which are essentially confined to glaciated catchments in late summer, when glacier runoff is the only source of surface runoff. Only this precise constraint of the hydrologic cycle in this complex region allows for unravelling of the surface processes and natural hazards such as floo...

show abstract

Dominance of tectonics over climate in Himalayan denudation

Cited by 189 publications

References 35 publications

<sup>10</sup>Be systematics in the Tsangpo-Brahmaputra catchment: the cosmogenic nuclide legacy of the eastern Himalayan syntaxis

<sup>10</sup>Be systematics in the Tsangpo-Brahmaputra catchment: the cosmogenic nuclide legacy of the eastern Himalayan syntaxis

Tectonic controls of Holocene erosion in a glaciated orogen

Sensitivity analysis and implications for surface processes from a hydrological modelling approach in the Gunt catchment, high Pamir Mountains

Contact Info

Product

Resources

About

Dominance of tectonics over climate in Himalayan denudation

Cited by 189 publications

References 35 publications

&lt;sup&gt;10&lt;/sup&gt;Be systematics in the Tsangpo-Brahmaputra catchment: the cosmogenic nuclide legacy of the eastern Himalayan syntaxis

&lt;sup&gt;10&lt;/sup&gt;Be systematics in the Tsangpo-Brahmaputra catchment: the cosmogenic nuclide legacy of the eastern Himalayan syntaxis

Tectonic controls of Holocene erosion in a glaciated orogen

Sensitivity analysis and implications for surface processes from a hydrological modelling approach in the Gunt catchment, high Pamir Mountains

Contact Info

Product

Resources

About

<sup>10</sup>Be systematics in the Tsangpo-Brahmaputra catchment: the cosmogenic nuclide legacy of the eastern Himalayan syntaxis

<sup>10</sup>Be systematics in the Tsangpo-Brahmaputra catchment: the cosmogenic nuclide legacy of the eastern Himalayan syntaxis