Modern erosion rates in the High Himalayas of Nepal

Gabet, Emmanuel J.; Burbank, Douglas W.; Pratt-Sitaula, Beth; Putkonen, Jaakko; Bookhagen, Bodo

doi:10.1016/j.epsl.2007.11.059

Cited by 163 publications

(171 citation statements)

References 55 publications

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“…12d, e). Similar results were reported earlier from the same region (France-Lanord et al, 2003;Tipper et al, 2006;Gabet et al, 2008;Bickle et al, 2018) and from other basins of the world (White and Blum, 1995;Gaillardet et al, 1999).…”

Section: Runoff Controlsupporting

confidence: 80%

Seasonal variations of biogeochemical matter export along the Langtang-Narayani river system in central Himalaya

Bhatt

Hartmann

Acevedo

2018

Geochimica et Cosmochimica Acta

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Weathering and suspended matter fluxes of the Langtang Narayani river system in central Nepal Himalaya have been investigated at 16 stations for one year, based on monthly water sampling in the lower reaches and bi-monthly in higher elevation areas, to determine temporal variations of weathering fluxes along an elevation profile between 169 and 3989 m asl. Results indicate that the lower reaches are the dominant places of weathering in the system. The sum of major base cation fluxes is 2.9 to 9.2 higher during the monsoon season compared to the pre-monsoon season. Alkalinity and sea-salt corrected sulfate were the dominant anions (97%). The lowest downstream location exports 1611 tons km À2 yr À1 suspended sediment, 78.56 tons km À2 yr À1 of major cations (Na + K + Mg + Ca), 12.72 tons km À2 yr À1 of silica (4-fold higher than at the middle reaches of the basin), and 1.9 Â 10 6 mol km À2 yr À1 of dissolved inorganic carbon (8.9-fold higher than at the middle reaches). Nitrogen and phosphorus concentrations are low in general and dissolved organic carbon export is within expected ranges. River water pCO 2 values are low in general, with exception of those main stem reaches where tributaries with relevant pyrite oxidation processes, and lower pH, alter the pattern locally. Element ratios suggest seasonal shifts in the weathering flux generation, modulated by the monsoon system. During the peak of the monsoon season the most relevant weathering products alkalinity, * SO 4 , * Ca and * Mg were not diluted, and increased concentrations observed at the lower reaches suggests an enhanced mobilization during this period of the year. Carbonate weathering exceeds silicate weathering along the drainage network and the carbonate-to silicate-cation mol ratio is 3.5 at the outlet. Sulfide oxidation probably enhances weathering rates besides the control of the soil-rock partial pressure of CO 2 . The ratio of the total alkalinity flux to sea-salt corrected sulfate equivalent flux at the base of the Himalaya at Narayanghat was 5.7. Sea-salt corrected sulfate equivalent export is about the same as the silicate cation-equivalent flux that leaves the system (98%). Therefore, further research on sulfur isotopes might be helpful to support the hypothesis that pyrite oxidation compensates for the idealized CO 2 -consumption by silicate weathering in the studied area.

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Section: Runoff Controlsupporting

confidence: 80%

Seasonal variations of biogeochemical matter export along the Langtang-Narayani river system in central Himalaya

Bhatt

Hartmann

Acevedo

2018

Geochimica et Cosmochimica Acta

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“…Rain water was sampled on a biweekly basis during the 2002 monsoon season but, unfortunately, many of the samples appeared to have been mislabeled and, thus, could not be trusted. Consequently, meteoric contributions are based on only two samples that were subsequently 1 The numbering scheme in this study differs systematically from the one utilized in a closely related paper (Gabet et al, 2008). The difference follows from the fact that watershed #3b in this study corresponds to #4 in Gabet et al (2008) with the implications for all following watersheds.…”

Section: Corrections and Errorsmentioning

confidence: 89%

“…Consequently, meteoric contributions are based on only two samples that were subsequently 1 The numbering scheme in this study differs systematically from the one utilized in a closely related paper (Gabet et al, 2008). The difference follows from the fact that watershed #3b in this study corresponds to #4 in Gabet et al (2008) with the implications for all following watersheds. While we treat the very same basins as the cited study, our numbering ends at 9 while theirs end at 10.…”

Section: Corrections and Errorsmentioning

confidence: 89%

Spatial variations in chemical weathering and CO2 consumption in Nepalese High Himalayan catchments during the monsoon season

Wolff-Boenisch

Gabet

Burbank

et al. 2009

Geochimica et Cosmochimica Acta

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“…This indicates that the flowing water is not the only source of river seismic signals and secondary signals are produced by sources in the river, probably moving bedload particles. No bedload data are available for Himalayan rivers at the time of writing, but a similar hysteresis loop between suspended sediment load and water discharge is known from other trans-Himalayan rivers (Gabet et al, 2008;Andermann et al, 2012;Struck et al, 2015), lending some weight to this interpretation. Hsu et al (2011) also found a hysteresis loop between discharge and seismic noise at the shorter timescale of a typhoon-induced flood along the Cho-Shui River, Taiwan.…”

Section: Ambient Monitoringmentioning

confidence: 96%

Seismic monitoring of torrential and fluvial processes

2016

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Abstract. In seismology, the signal is usually analysed for earthquake data, but earthquakes represent less than 1 % of continuous recording. The remaining data are considered as seismic noise and were for a long time ignored. Over the past decades, the analysis of seismic noise has constantly increased in popularity, and this has led to the development of new approaches and applications in geophysics. The study of continuous seismic records is now open to other disciplines, like geomorphology. The motion of mass at the Earth's surface generates seismic waves that are recorded by nearby seismometers and can be used to monitor mass transfer throughout the landscape. Surface processes vary in nature, mechanism, magnitude, space and time, and this variability can be observed in the seismic signals. This contribution gives an overview of the development and current opportunities for the seismic monitoring of geomorphic processes. We first describe the common principles of seismic signal monitoring and introduce time-frequency analysis for the purpose of identification and differentiation of surface processes. Second, we present techniques to detect, locate and quantify geomorphic events. Third, we review the diverse layout of seismic arrays and highlight their advantages and limitations for specific processes, like slope or channel activity. Finally, we illustrate all these characteristics with the analysis of seismic data acquired in a small debris-flow catchment where geomorphic events show interactions and feedbacks. Further developments must aim to fully understand the richness of the continuous seismic signals, to better quantify the geomorphic activity and to improve the performance of warning systems. Seismic monitoring may ultimately allow the continuous survey of erosion and transfer of sediments in the landscape on the scales of external forcing.

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Modern erosion rates in the High Himalayas of Nepal

Cited by 163 publications

References 55 publications

Seasonal variations of biogeochemical matter export along the Langtang-Narayani river system in central Himalaya

Seasonal variations of biogeochemical matter export along the Langtang-Narayani river system in central Himalaya

Spatial variations in chemical weathering and CO2 consumption in Nepalese High Himalayan catchments during the monsoon season

Seismic monitoring of torrential and fluvial processes

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