Decadal terminus position changes and ice thickness measurement of Menthosa Glacier in Lahaul region of North-Western Himalaya

Abstract

Glacier ice-thickness measurement and distribution is one of the essential variables to assess present status of glacier-water equivalent and its volumetric reserve as well as to model the future glacier dynamics under the climate changing scenario. Yet, substantial gaps in ice thickness information exist for the Himalayan glaciers. The present study provides a long-term assessment (1965–2016) of recessional and area change patterns, as well as the detailed field-based (2016–2017) Ground Penetrating Radar(GPR), derived ice-thickness measurement of the Menthosa Glacier, Lahaul Himalaya. Additionally, the study examines whether the modelled ice thickness from remote sensing data is consistent with the field-based GPR measurement and how can it be improved. The extensive field surveys coupled with the multi-temporal high (Corona KH-4A) to medium resolution (Landsat Enhanced Thematic Mapper+ (ETM+)/Operational Land Imager (OLI), Sentinel 2A-Multispectral Instrument (MSI)) remote sensing data and cross-sectional GPR surveyed profile measurements have been used to examine past half a century (1965–2016) glacier fluctuation and the recent ice-thickness estimations, respectively. The results show that the Menthosa Glacier receded by 301.5 ± 19.2 m during the past half a century (1965–2016) with an average annual retreat of 5.9 ± 0.4 m a⁻¹, whereas glacier lost 0.09 km² ice in the frontal section. Field measurement over the past one decade (2006–2017) also conforms to a continuous recessional pattern and substantial glacier degeneration particularly the extensive surface lowering and significant appearance of ice-cliffs in the ablation and lateral zones over this period. The GPR measurements (2017) show the minimum glacier ice thickness of 24 meters at 4691 m a.s.l. (in the lower part of ablation area) and maximum glacier ice thickness of 55 meters measured at 4758 m a.s.l. (in the upper left-side tributary part of ablation area). Moreover, the modelled ice thickness derived from remotely sensed data is having Root Mean Square Error (RMSE) between 38 to 72 ± 10 m as compared with GPR measured ice thickness.

Keywords:

• Glacier terminus changes
• glacier ice-thickness
• Ground Penetrating Radar (GPR)
• remote sensing
• Lahaul Himalaya

Acknowledgments

This work was financially supported by the Department of Science and Technology and the Space Applications Centre/ISRO Ahmadabad, Government of India, over 2013–2019. We are thankful to anonymous reviewers and the editorial board for providing constructive comments and suggestions which helped us to improve the content of the manuscript. The authors are thankful to the Jawaharlal Nehru University, New Delhi (India) for providing research facility and infrastructure. We also would record our thanks to Mr Satish Kumar, and Tenzin Dorje for assistance in the GPR & GPS surveys. Our special thanks to the villagers of Urgos and Tingrit for extending logistical support all this while. The authors acknowledge the USGS for providing satellite data except IRS LISS-IV for this research at free of cost. Pritam Chand is grateful to the Central University of Punjab, Bathinda (India).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.