Glaciological mass balance (MB) is considered the most direct,undelayed and unfiltered response of the glaciers to climatic perturbations.However,it may inherit errors associated with stake under-representation,averaging over the entire glacier and human bias.Therefore,proper validation of glacio-logical MB with geodetic MB is highly recommended by the World Glacier Monitoring Service (WGMS).The present study focuses on the Dokriani Glacier,central Himalaya which is one of the bench-mark gla-ciers in the region and has glaciological MB records from 1993 to 2013 with intermittent gaps.In the pre-sent study,firstly the glaciological MB series is extended to 2014 i.e.,field-based MB for one more year is computed and,to compare with it,the geodetic MB is computed for the 1999-2014 period using high resolution Cartosat-1 digital elevation model (DEM) and SRTM DEM.Finally,the study assesses the regio-nal representation of the Dokriani Glacier in terms of MB and evaluates the influence of the MB regime on its morphological evolution.Results show that the average glaciological MB (-0.34 ± 0.2 m water equiv-alent (w.e.) y-1) is more negative than the geodetic MB (-0.23 ± 0.1 m w.e.y-1) for the 1999-2014 per-iod.This is likely because of the partial representation of glacier margins in the glaciological MB,where melting is strikingly low owing to thick debris cover (＞30 cm).In contrast,geodetic MB considers all mar-ginal pixels leading to a comparatively low MB.A comparative assessment shows that the MB of Dokriani Glacier is less negative (possibly due to its huge accumulation area) than most other glacier-specific and regional MBs,restricting it to be a representative glacier in the region.Moreover,continuous negative MB has brought a peculiar change in the epiglacial morphology in the lower tongue of the glacier as differ-ential debris thickness-induced differential melting has turned the glacier surface into a concave one.This concavity has led to development of a large (10-20 m deep) supraglacial channel which is expanding incessantly.The supraglacial channel is also connected with the snout wall and accelerates terminus dis-integration.Given the total thickness of about 30-50 m in the lower glacier tongue,downwasting at its current pace,deepening/widening of supraglacial channel coupled with rapid terminus retreat may lead to the complete vanishing of the lower one km glacier tongue.

Purushottam Kumar Garg;Jairam Singh Yadav;Santosh Kumar Rai;Aparna Shukla

Indian Institute of Technology Indore,Khandwa Road,Simrol,Indore 453552,India;Wadia Institute of Himalayan Geology,33,GMS Road,Dehradun 248001,India;Ministry of Earth Sciences,Prithvi Bhavan,Lodhi Road,New Delhi 110003,India

地学前缘（英文版）

[1]Purushottam Kumar Garg;Jairam Singh Yadav;Santosh Kumar Rai;Aparna Shukla-.Mass balance and morphological evolution of the Dokriani Glacier,central Himalaya,India during 1999-2014)[J].地学前缘（英文版）,2022(01):255-267

Dokriani,Glaciological,undelayed,unfiltered,glacio,WGMS,ciers,glaciological,Cartosat,iod,ginal,epiglacial,supraglacial,snout,downwasting

Mass,balance,morphological,evolution,Glacier,central,Himalaya,India,during,mass,considered,most,direct,response,glaciers,climatic,perturbations,However,may,inherit,errors,associated,stake,under,representation,averaging,entire,human,bias,Therefore,proper,validation,geodetic,highly,recommended,by,World,Monitoring,Service,study,focuses,which,one,bench,mark,has,records,from,intermittent,gaps,firstly,series,extended,field,more,year,computed,compare,period,using,resolution,digital,elevation,model,DEM,SRTM,Finally,assesses,terms,evaluates,influence,regime,its,Results,that,average,water,equiv,alent,negative,than,This,likely,because,partial,margins,where,melting,strikingly,owing,debris,cover,contrast,considers,pixels,leading,comparatively,assessment,shows,less,possibly,due,huge,accumulation,area,other,specific,regional,MBs,restricting,representative,Moreover,continuous,brought,peculiar,change,morphology,lower,tongue,thickness,induced,differential,turned,surface,into,concave,concavity,development,large,channel,expanding,incessantly,also,connected,wall,accelerates,terminus,dis,integration,Given,total,about,current,pace,deepening,widening,coupled,rapid,retreat,complete,vanishing

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