Climate Change and State of Himalayan Glaciers: Issues, Challenges and Facts

Transcription

1 Climate Change and State of Himalayan Glaciers: Issues, Challenges and Facts D.P. Dobhal Wadia Institute of Himalayan Geology Dehra Dun

2 Major Issues Are the Himalayan glaciers receding rapidly? What are the main controlling factors Is the recession more to global warming or due to the inadequate precipitation? What is the relationship between mass balance and frontal fluctuation? What are the main influencing agents Is it possible to decipher influence of each factor?

3 Are Himalayan glaciers affected by naturally occurring cause of Climate Change or present recession trends are transient expressions of long term cyclic variation? Can relationship between Glacier mass and climate change be used to understand mechanism of glacier recession? What methodology is best suited to assess the recession of Himalayan glaciers?

4 Challenges Himalaya is experiencing rapid recession of glaciers like all glaciated regions of the world What should we expect from glacier changes? What will be the consequences? What will we need to adapt?

5 GLACIERS RETREAT - FACTS Glacier retreat is a natural phenomenon / real Glaciers have been retreating worldwide Accelerated retreat reported after 1980 Sensitive to climate, and to be considered an indicator of climate change

6 Climate is a natural phenomenon: Major causes: Solar forcing Orbital forcing Radiative forcing Greenhouse gases, aerosols, dust (Global warming)

7 Rapid Change in Global Average Temperature

8 Daily Mean Temperature of Dokriani Glacier ( ) 10 Summer Temp Winter Temp Temperature ( C) Jan Jan Jan Jan Jan Jan Jan Jan Jan Jan Jan Temperature (0C) 10 Jan-1-4 Temperature scenario in High altitude region : Dokriani Glacier (3900m asl)

9 World Glaciers Distribution 13.9% 0.062% 0.51% 0.77% 0.15% 10% of earth landmass 0.37% 84.16%

10 Climate zone of the Himalaya (Moisture sources for glacier development) Winter Snow Length: 2500 Width: km Latitude : North WD + Monsoon Monsoon

11 Indian Himalayan Glacier System Number of Glaciers - ~ 9575 Glacierized area km2 Total ice volume km3 Jammu & Kashmir Himachal Uttarakhand Sikkim INDIA Arunachal Glaciers Area (Km2) Average Size (Km2) Glacier (%) Jammu & Kashmir Himachal Pradesh Uttarakhand Sikkim Arunachal Pradesh State (Raina and Srivastava, 2008)

12 Glaciers number, Ice Volume and Area Glaciers no.% 66.42% 26.59% Area % Ice Volume % % % % 12.25% 27.49% % % 14.33% 12.82% % 5.53% 4.18% 4.04% % 6.88% 6.87% 4.27% 4.45% 4.12% 1.16% Glaciers Volume (%) Glaciers no. (%) % 0.41% 0.57% 0.21% 0.12% < 1 km2 1-5 km km km km km km km2 >100 km2 Glacier Area (km2) Source; Based on Glacier inventory, GSI,2009

13 Important Glaciers of the Himalaya Siachen Biafo Hispar Baltoro Batura Rimo Choglungma Gashbrum Gangotri Zemu Milam : 72 : 62 : 61 : 58 : 58 : 40 : 39 : 39 : 30 : 26 : 19 Kanchenjunga Barashigri Miyar Chhota Shigri Satopanth Bhagirath Kharak Dokriani Chorabari Dunagri Pindari Nanda Devi : 16 : 29 : 27 : 09 : 13 : 17 : 5.5 : 6.0 : 6.0 : 5.0 : 22

14 Recession trends of Glaciers in Himalaya (NW- NE) Rates of glacier retreat vary considerably; between <5 to 20 m/year. (Source: GSI, WIHG & ICIMOD)

15 Fluctuation of Snout Retreat of Himalayan Glaciers Dobhal et al, 2014

16 Snout retreat of Gangotri Glacier ( ) Length reduced 819 ± 14 m and frontal area lost 0.41 ± 0.03 sq. km Bhambri el al., 2012, Current Science

17 Changes in Snout of the Gangotri Glacier 1991 Dobhal, 1991 After 20 Years 2012 Dobhal.2012

18 Recession of Dokriani glacier to 2014 Frontal recession constitutes just 10% overall shrinkage Total Frontal Retreat = 876 m; 16.8m/yr Total Frontal Area Loss 0.78 km2 Total ice mass loss - ~ 2.45 x 106 m3 w.e.

19 Changes in glacier surface morphology Surface lowering (Volume loss) in Dokriani glacier during a period of 13 years i) Rapid surface thinning ii) Decrease of snow cover (transition snowline) iii) Increase of debris cover in lower ablation area (Dobhal & Mehta,2009)

20 Change in Chorabari Glacier, Kedarnath 1882 Grieshbatch,1882 After 128 Years 2010 Dobhal, 2010

21 Typical view of Himalayan glacier Chorabari Glacier, Kedarnath Length : 6.5km Thickness : 30-75m

22 Fragmentation of Larger Glacier Chorabari Glacier- Glacier lost 0.71 km2 (9.6%) Tipra Glacier- Glacier lost 2.6 km2 (18%) Tipra Glacier- Glacier lost 2.6 km2 (18%) Chorabari Glacier Glacier lost 0.71 km2 (9.6%) Mehta et al, 2012 Jaundhar Glacier- Glacier lost 2.68 km2 (4.7%)

23 Small glaciers are more prone to melting

24 Supra-glacial Lakes

25 Lateral Moraine Dam Lake Satopanth Glacier (4200m asl) : Chorabari Glacier (3920m asl)

26 End Moraine-dammed lake South Lhonak Lake, Sikkim Himalaya

27 Cirque/ Glacier erosion lake Hem-kund Lake (4400 m asl),uttarakhand Himalaya

28 Chorabari Lake (3905m asl); Uttarakhand Himalaya Chorabari Lake

29 Chorabari Lake burst on June 17, 2013 Kedarnath Town Chorabari Lake

30 Chorabari Glacier Lake Burst and its impacts 17 June,2013 Chorabari Glacier N Before Companion Glacier After

31 Glacier Monitoring Stations of Upper Ganga Basin Centre For Glaciology Wadia Institute of Himalayan Geology Chorabari Dokriani Dunagiri Gangotri

32

33 Glacier lake inventory of Uttarakhand Main type Moraine-dammed lake Ice-dammed lake Glacier erosion lake Other glacial lake Total number % Total area (m)2 End moraine-dammed lake Lateral moraine-dammed lake Recessional moraine-dammed lake Other moraine-dammed lake Supra-glacial lake 809 Cirque lake Sub type Other glacial erosion lake Other glacial lake Total % Mean area (m)

34