Accumulation and flow rates of ice on Chhota Shigri glacier, central Himalaya, using radio-active and stable isotopes

Nijampurkar, V. N.; Rao, D. K.

doi:10.3189/s0022143000009588

Cited by 14 publications

(14 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…18 O concentrations in snow, pits, surface ice and a shallow ice core d 18 O concentrations in snow and ice The results of the analysis of the fresh snow and surface ice samples collected at different altitudes (in both the accumulation and ablation zones of the glacier) are shown in Figure 3.The d 18 O in snow samples varied from^5% to^9%; however, there is no systematic variation of d 18 O with increasing altitude, as these samples represent only a single snowfall event and not the annual precipitation. These oxygen isotope ratios are similar to those reported in our earlier studies on Himalayan glaciers (Nijampurkar and Bhandari, 1984;Nijampurkar and Rao, 1992). The d 18 O values of surface ice samples at different altitudes range from^11% tô 13.4%.…”

supporting

confidence: 89%

Isotopic study on Dokriani Bamak glacier, central Himalaya: implications for climatic changes and ice dynamics

Nijampurkar¹,

Rao²,

Sarin³

et al. 2002

J. Glaciol.

View full text Add to dashboard Cite

Measurements of natural and artificial radioisotopes (32Si, 210Pb and 137Cs) and oxygen isotopes (δ18O) have been carried out on surface snow and ice, shallow snow pits and an ice core collected from Dokriani Bamak glacier, central Himalaya, to study the dynamics of glacier ice and short-term climatic changes. Based on the 32Si and 210Pb activities in the meltwaters, the age of the snout ice is 400 years and the flow rate of ice along the glacier length is ∼14 m a−1. The specific activity of 137Cs, corresponding to 1963 fallout, in the surface ice at the equilibrium line yields a flow rate of 32 m a−1, a factor of two higher than that derived for the snout ice. The depth variation of 137Cs concentration in a shallow ice core yields a mean accumulation rate of 0.43 m a−1 for the glacier ice over the past decade. The δ18O of snout ice (−13.4‰) is significantly depleted compared to the average value of −9.2‰ in the shallow ice core, indicating that cooler climatic conditions prevailed around AD 1600. Based on the oxygen isotopic ratios in the shallow pits, an “altitude effect” of 0.9‰ per 100 m in δ18O variation is documented for this glacier.

show abstract

supporting

confidence: 89%

Isotopic study on Dokriani Bamak glacier, central Himalaya: implications for climatic changes and ice dynamics

Nijampurkar¹,

Rao²,

Sarin³

et al. 2002

J. Glaciol.

View full text Add to dashboard Cite

show abstract

“…in western Tibet (Owen and Benn, 2005). The seasonal distribution of precipitation creates glaciers of the summer accumulation type, with maxima in accumulation and ablation occurring more or less simultaneously during the summer, in most of the region (Ageta and Higuchi, 1984;Owen and Derbyshire, 1989;Benn and Owen, 1998;Ageta and Kadota, 1992;Kulkarni, 1992;Nijampurkar and Rao, 1992). The summer accumulation maximum reflects high precipitation during the summer monsoon, when moisture-bearing air masses originating over the Indian Ocean bring snow to high altitudes in the Himalaya and western Tibet (Yasunari and Inoue, 1978;Higuchi et al, 1982;Ageta and Higuchi, 1984).…”

Section: Physical Settingmentioning

confidence: 99%

Quaternary glaciation of the Himalayan–Tibetan orogen

Owen

Caffee

Finkel

et al. 2008

J Quaternary Science

210

143

View full text Add to dashboard Cite

Glacial geological evidence from throughout the Himalayan-Tibetan orogen is examined to determine the timing and extent of late Quaternary glaciation in this region and its relation to similar changes on a global scale. The evidence summarised here supports the existence of expanded ice caps and extensive valley glacier systems throughout the region during the late Quaternary. However, it cannot yet be determined whether the timing of the extent of maximum glaciation was synchronous throughout the entire region or whether the response was more varied. The lack of organic material needed for radiocarbon dating has hindered past progress in glacial reconstruction; however, application of optically stimulated luminescence and terrestrial cosmogenic radionuclide methods has recently expanded the number of chronologies throughout the region. Limits to the precision and accuracy available with these methods and, more importantly, geological uncertainty imposed by processes of moraine formation and alteration both conspire to limit the time resolution on which correlations can be made to Milankovitch timescales (several ka). In order to put all studies on a common scale, well-dated sites have been re-evaluated and all the published terrestrial cosmogenic nuclide ages for moraine boulders and glacially eroded surfaces in the Himalayan-Tibetan orogen have been recalculated. Locally detailed studies indicate that there are considerable variations in the extent of glaciation from one region to the next during a glaciation. Glaciers throughout monsoon-influenced Tibet, the Himalaya and the Transhimalaya are likely synchronous both with climate change resulting from oscillations in the South Asian monsoon and with Northern Hemisphere cooling cycles. In contrast, glaciers in Pamir in the far western regions of the Himalayan-Tibet orogen advanced asynchronously relative to the other regions that are monsooninfluenced regions and appear to be mainly in phase with the Northern Hemisphere cooling cycles. Broad patterns of local and regional variability based on equilibrium-line altitudes have yet to be fully assessed, but have the potential to help define changes in climatic gradients over time.

show abstract

“…Time series of (a) δ 18 O and δD; (b) d ‐excess values for the Parbati River water samples; (C) comparison of δ 18 O values of the Parbati River water samples (present study) with some precipitation isotope data taken from nearby high elevation stations (Kumar et al, ). δ 18 O values of meltwater, surface snow, and surface ice from Chhota Shigri glacier along with the variations also presented (Giggenbach, Gonfiantini, & Truesdell, ; Nijampurkar & Rao, ; see text for details of the sampling times in these studies)…”

Section: Resultsmentioning

confidence: 56%

Seasonal variation in stable isotope compositions of waters from a Himalayan river: Estimation of glacier melt contribution

Laskar

Bhattacharya

Rao

et al. 2018

Hydrological Processes

View full text Add to dashboard Cite

Stable isotopic compositions (δ18O and δD) in water samples collected from Parbati River in Himachal Pradesh, India, during 2002–2005 were measured to delineate the contributions from different sources in different seasons. A seasonal cycle with high δ18O and δD values (in ‰) during the spring (March to May; −9.2, −58.6), intermediate values during the winter (December to February; −10.1, −65.6), and low values during the south‐west monsoon (July to September; −10.9, −71.8) is observed. The d‐excess values (15.2 ± 2.1‰) are higher compared with the global meteoric waters indicating significant contribution (~26%) of moisture carried by western disturbances. Higher δ‐values during the spring are ascribed to enhanced contribution from snow melt. The lower δ‐values during the monsoon are due to various Rayleigh effects (altitude, continental, and amount effects) and large‐scale convection effect on rains. A three component‐mixing model using the isotopic data and some plausible end member isotopic values was applied to identify contributions to the river discharge from different sources such as groundwater or subsurface base flow, glacier/surface snow melt, and the monsoon rain. Meltwater from glacier and snow combines with the base flow in spring season. South‐west monsoon rain and glacier melt along with the base flow constitute the monsoon discharge. The post‐monsoon season and winter are dominated by groundwater contribution. About 80% of the discharge is contributed by glacier melts in spring season. In the rainy monsoon season, glacier/snow melt contributes ~41% of the discharge. The mean annual glacier melt contribution to the river water is estimated to be 44 ± 15%. The present estimate along with some previous studies suggest that glacier contribution to the river discharge increased from ~35% to 50% during the period 1990 to 2011. This is consistent with recent data on glacier retreats in the Himalayan region.

show abstract

Accumulation and flow rates of ice on Chhota Shigri glacier, central Himalaya, using radio-active and stable isotopes

Cited by 14 publications

References 35 publications

Isotopic study on Dokriani Bamak glacier, central Himalaya: implications for climatic changes and ice dynamics

Isotopic study on Dokriani Bamak glacier, central Himalaya: implications for climatic changes and ice dynamics

Quaternary glaciation of the Himalayan–Tibetan orogen

Seasonal variation in stable isotope compositions of waters from a Himalayan river: Estimation of glacier melt contribution

Contact Info

Product

Resources

About