1. A 3D inventory of Austrian glaciers Measuring and scaling thickness, area and volume comparison to the 1969 inventory M.Kuhn, R. Würländer, N.Span Institute of Meteorology and Geophysics University of Innsbruck

2. For their assistance we are thankful to M.Butschek, S.Lentner, F.Pellet, E.Schlosser, A. Fischer

3. Motivation 1. Still no global coverage 540.000 54.000 540

4. Water cycle 2. Glaciers are part of the water cycle 3. They contribute to sea level rise

5. 4. Glaciers are a clean water resource Only 2% of all water is non-saline 98% of that is in Antartica and Greenland

6. Hintereisferner Span 2001 Glaciers are documents of global change

7. 1894

8. 19201920 1920

9. 1939

10. 1953

11. 1967

12. 1979

13. 1997

14. Why three-dimensional ? Knowing thickness is more important than volume Z is essential for modelling

15. Measurements 1.Area:remote sensing 2.Area / altitude: aerial photogrammetry 3.Thickness: Radio - echo - sounding

16. Pasterze

17. Austrian Gletscherkataster 1969 1969: original evaluation by Patzelt & Gross Maps 1 : 10.000 With extent of firn, bare ice, debris covered ice Glacier extent 1850 and 1920 where available Summary 1969 925 glaciers > 0.01 km 2 Total area 540 km 2

18. New inventories 1998 inventory: photogrammetric evaluation 1969 partly new photogrammetric evaluation partly digitalization of old maps 30 m grid digital elevation models Vectorized ice margins Maps and orthophotos 1:10.000 Accuracy of surface elevation at rms <.75 m

19. Classification problems

20. Decisions: one or two? debris or debris covered ice?

21. Size spectrum 1969

22. Scaling Parameter scaling:Volume / area Length / thickness Upscaling: from one glacier to an entire mountain group Downscaling: from a GCM to a glacier

23. volume/area V = 0.02 A 1.45

24. Vorderseeferner Pichler 1998

25. Length / thickness scaling Antarctica L = 5000 kmH = 3 km H/L = 0.6 10 -3 A4 paper, 80 g L = 297 mm H = 0.15 mmH/L = 0.5 10 -3 Cirque glacier L = 500 m H = 50 mH/L = 10 -2

26. Climatic impact

27. Gewester Gletscher Napfspitze, Zillertal

28. An inverse problem Climate P, u T, R Accumulation Ablation Mass balance Ice flow Glacier advance, moraines

29. 1996 - 1969 Advance of the 1970s has travelled downglacier like a wave

30. Non-linear flow

31. Austrian glacier inventory, summary 1969 + 1998Digital elevation model of glacier surface 1998 Thickness of major glaciers and representative small glaciers, volume / area scaling for others 1998 –69 Thickness and area changes as basis for models of mass balance and ice flow and of the reaction of glaciers to climate change