Relative effect of slope and equilibrium line altitude on the retreat of Himalayan glaciers

Abstract

Abstract. It has been observed that a majority of glaciers in the Himalayas have been retreating. In this paper, we show that there are two major factors which control the advance/retreat of the Himalayan glaciers. They are the slope of the glacier and changes in the equilibrium line altitude. While it is well known, that these factors are important, we propose a new way of combining them and use it to predict retreat. The functional form of this model has been derived from numerical simulations using an ice-flow code. The model has been successfully applied to the movement of eight Himalayan glaciers during the past 25 years. It explains why the Gangotri glacier is retreating while Zemu of nearly the same length is stationary, even if they are subject to similar environmental changes. The model has also been applied to a larger set of glaciers in the Parbati basin, for which retreat based on satellite data is available, though over a shorter time period.

Regional climate forcing and topographic influence on glacier shrinkage: eastern cordilleras of Peru

“…in the Vilcabamba area. Slope (Venkatesh et al, 2012) and slope stability (Haeberli et al, 1997) may also be crucial in glacier shrinkage, particularly when the study region is seismically active. Even though there was a decrease in mean annual precipitation, an increase in summer precipitation (DJF) was observed, possibly caused by conditions of humidity increase.…”

Evaluating the contribution of avalanching to the mass balance of Himalayan glaciers

“…However, the f s and f d values are typically used as a tuning parameters of the model (Adhikari and Huybrechts, 2009). The values used in modelling various glaciers in the Himalaya are in the range 0.19 − 1.75 × 10 −20 Pa −3 m 2 s −1 for f s , and 1.7 − 5.3 × 10 −25 Pa −3 s −1 for f d (Adhikari and Huybrechts, 2009; Venkatesh and others, 2012; Banerjee and Shankar, 2013; Banerjee and Azam, 2016). Starting with an initial thickness distribution, if the mass-balance profile as a function of time are known, then Eqn (2) can be used to find out h ( x , t ) at all subsequent time t for any given bedrock geometry and width distribution.…”

Recession and Morphological Changes of the Debris-Covered Milam Glacier in Gori Ganga Valley, Central Himalaya, India, Derived From Satellite Data

“…A review of studies on Himalayan glaciers suggests spatially variable and irregular glacier response patterns across the Karakorum-Himalayan mountain (Mayewski and Jeschke, 1979;Scherler et al, 2011;Bolch et al, 2012Bolch et al, , 2019Kääb et al, 2012Kääb et al, , 2015Schickhoff et al, 2016;Azam et al, 2018). This spatially variable glacier response is linked to the spatial variability of changing climatic conditions (temperature and precipitation trends) and geomorphic factors; including local physiography, slope of glacier bed, glacier geometry, extent and thickness of debris cover, slope-aspects, elevation characteristics and glacial lake activities (Sakai et al, 2009;Raina, 2010;Bhambri et al, 2011a;Deota et al, 2011;Scherler et al, 2011;Bolch et al, 2012Bolch et al, , 2019Venkatesh et al, 2013;Nainwal et al, 2016;Shukla and Qadir, 2016).…”

“…In general, the debris free glaciers show relatively higher recession rates when compared to those covered with debris (Scherler et al, 2011;Shukla and Qadir, 2016). In addition, considering slope of the glacier bed as an important factor of glacier recession, several studies suggest that glaciers with steep slopes have receded at lower rates when compared to those with gentle slopes (Venkatesh et al, 2013;Nainwal et al, 2016). Further, Deota et al (2011) suggest that south-facing glaciers have receded much faster than those facing north.…”