Mapping Glaciers and surging glaciers in the Karakoram using satellite data

Transcription

1 Mapping Glaciers and surging glaciers in the Karakoram using satellite data Frank Paul Department of Geography University of Zurich Sentinel 2: Copernicus 2015! Satellites Image source: Internet

2 Landsat 8 (30 m) Landsat data: USGS! Paul! Sentinel 2 (10 m) Sentinel 2: Copernicus 2015! Paul!

3 Sensors: timelines and applications Optical outlines velocity (DEMs) DEMs elev. change (inventories) Altimeters elev. change Microwave velocity (DEMs) Paul (Glaciers_cci) Paul! Change in spectral bands (optical sensors) Courtesy: A. Kääb! Paul!

4 A typical alpine glacier crevasses snow bare ice debris rock Photo: Paul! Paul! Spectral properties and glacier mapping TM3 TM5 Red/SWIR TM/ETM+: 3/5 ASTER: 2/4 OLI: 4/6 (8/6) MSI: 4/11 Ratio Mask Outlines Paul!

5 Glacier mapping with Landsat 8 OLI & Sentinel 2 MSI Landsat OLI (pan/swir) Sentinel 2 MSI (red/swir & blue) all colours 1.40 removed by 1.38 all colours removed by removed by MSI requires an additional threshold in the blue band to achieve the same performance in cast shadow as OLI Paul! Glacier mapping with Landsat 8 OLI & Sentinel 2 MSI OLI red/swir (30 m) OLI pan/swir (15 m) MSI red/swir (10 m) Sentinel 2: Copernicus 2015! Paul et al. (2016)! Paul!

6 Debris-covered glaciers: Manual mapping Landsat data: USGS! Strozzi et al. (2010) Debris-covered glaciers: Coherence images Strozzi et al. (2010) ALOS PALSAR data: JAXA!

7 Accuracy: manual glacier delineation (Landsat) Landsat data: USGS! Paul et al. (2015) Time series of area changes Marzeion et al. (in press)

8 Surging glaciers in the Central Karakoram Google Earth! Study region & surging glaciers Copland et al. 2011!

9 Surge-type glaciers and research questions Criteria to identify surge-type glaciers Skamri surge-type - historic evidence - length changes (? km) - advance rates (>? m/a) - flow velocity (>? m/d) - surface appearance => wide range of values - surge / quiescent phase - repeat surges? - constant period? Shingchukpi K2 1 st Feriole Historic documents and field evidence Surging Shingchukpi Glacier (2005) Copland et al. 2011! Hewitt 2007!

10 Velocity fields from optical and microwave sensors 2006/07 ASTER 2009/10 TerraSAR-X Copland et al. 2009! Rankl et al. 2014! Multi-temporal elevation and length changes DEM differencing SRTM-SPOT Outlines Landsat Gardelle et al. 2013! Rankl et al. 2014!

11 Time series with surging tributary glaciers Corona Hexagon Hexagon 500 m TM B3 TM 543 ETM+ pan All images: USGS! Surging glaciers Nr. 7 & 8 in Moniglacier Michael Beek!

12 Conclusions Karakoram glaciers received a surge of attention recently Annual length changes, decadal volume changes, velocity fields and their changes through time have been derived Previous surges were noted, but not further investigated Non-surging glaciers have not changed much since 1960s Surge-type glaciers are often steep, small and debris-free and surge periodically (every y), but non-synchronous Likely no climatic reasons for surging, but others also stable Surging glaciers should be excluded in CC impact assessm. Thank you for attention! Cited studies Bhambri, R., Bolch, T., Kawishwar, P., Dobhal, D. P., Srivastava, D., and Pratap, B. (2013): Heterogeneity in glacier response in the upper Shyok valley, northeast Karakoram, The Cryosphere, 7, Bolch, T., Kulkarni, A., Kääb, A., Huggel, H., Paul, F., Cogley, J.G., Frey, H., Kargel, J.S., Fujita, K., Scheel, M., Bajracharya, S. and Stoffel, M. (2012): The state and fate of Himalayan glaciers. Science, 336, Copland, L., Pope, S., Bishop, M., Shroder, J., Clendon, P., Bush, A., Kamp, U., Seong, Y., and Owen, L. (2009): Glacier velocities across the central Karakoram, Ann. Glaciol., 50, Copland, L., Sylvestre, T., Bishop, M., Shroder, J., Seong, Y., Owen, L., Bush, A., and Kamp, U. (2011): Expanded and recently increased glacier surging in the Karakoram, Arct. Antarct. Alp. Res., 43, Gardelle, J., Berthier, E., Arnaud, Y., and Kääb, A. (2013): Region-wide glacier mass balances over the Pamir- Karakoram-Himalaya dur- ing , The Cryosphere, 7, Gardner, A.S., G. Moholdt, J.G. Cogley, B. Wouters, A.A. Arendt, J. Wahr, E. Berthier, R. Hock, W.T. Pfeffer, G. Kaser, S.R.M. Ligtenberg, T. Bolch, M.J. Sharp, J.O. Hagen, M.R. van den Broecke and F. Paul (2013): A consensus estimate of glacier contributions to sea level rise: 2003 to Science, 340 (6134), Heid, T. and Kääb, A. (2012): Repeat optical satellite images reveal widespread and long term decrease in landterminating glacier speeds. The Cryosphere, 6, Hewitt, K. (2007): Tributary glacier surges: an exceptional concentration at Panmah Glacier, Karakoram Himalaya, J. Glaciol., 53, Marzeion, B., N. Champollion, W. Haeberli, K. Langley, P. Leclercq, F. Paul (in press): Observation of glacier mass changes on the global scale and its contribution to sea level change. Surveys in Geophysics. Paul, F., S.H. Winsvold, A. Kääb, T. Nagler and G. Schwaizer (2016): Glacier Remote Sensing Using Sentinel-2. Part II: Mapping Glacier Extents and Surface Facies, and Comparison to Landsat 8. Remote Sens., 8(7), 575. Quincey, D. J., Braun, M., Glasser, N. F., Bishop, M. P., Hewitt, K., and Luckman, A. (2011): Karakoram glacier surge dynamics, Geophys. Res. Lett., 38, L18504, doi: /2011GL Rankl, M., Kienholz, C., Braun, M. (2014): Glacier changes in the Karakoram region mapped by multimission satellite imagery. In: The Cryosphere 8, Strozzi, T., F. Paul and A. Kääb (2010): Glacier mapping with ALOS PALSAR data within the ESA GlobGlacier project. Proc. ESA Living Planet Symposium, Bergen, Norway , ESA SP-686.