Fundamental questions to consider: How likely is a glacier lake outburst flood?

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Irene Phillips
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1 Fundamental questions to consider: How likely is a glacier lake outburst flood? How large will the flood be? How far will the flow reach?

2 Estimate of probability of dam failure Palcacocha Indicator Attribute Qualitative probability Dam type Freeboard to dam height ratio Impact waves by ice/rock falls reaching the lake Kinzl 1932 Ice Moraine Bedrock Low Medium High Dam width to height ratio Small, Medium, Large, > 0.5 Extreme meteorological events (high temperature/ precipitation) Frequent / large volume Sporadic / medium volume Unlikely / small volume Frequent Sporadic Unlikely High Medium to high Low High Medium Low High Medium Low High Medium Low High Medium Low Patzelt 2004 from Huggel et al., 2004

3 Estimate of maximum discharge for different outburst mechanisms Palcacocha Patzelt 2004 Kinzl 1932 from Walder and Costa, 1996

4 Estimate of maximum discharge for moraine-dammed lakes Palcacocha Patzelt 2004 Kinzl 1932 from Huggel et al., 2002

5 Type of lake and dam failures Palcacocha Patzelt 2004 Kinzl 1932 from Huggel et al., 2002

6 Estimate of maximum runout (reach) Palcacocha Patzelt 2004 Kinzl 1932 from Huggel et al., 2002

7 W. Haeberli

8 Huandoy Huascaran Hualcan Palcaraju

9 Palcacocha Patzelt 2004 Kinzl 1932

10 W. Haeberli

11 W. Haeberli

12 W. Haeberli

13 W. Haeberli

14 Impact waves from rock/ice avalanches into new glacial lakes: lessons learned from the Nevado Hualcán/Laguna 513 event of 11 April 2010

15 Nevado Hualcán Laguna 513 Pampa de Shonquil Río Chucchún

17 Potentially inundated areas by GLOF Reynolds et al. (1998)

18 October 1988: 1 syphon: 190 l/s Christmas 1988: 1 million m 3 drained but lake level remains the same January 1989: another syphon, total drainage capacity 500 l/s March 1989: lake level lowered by 2 m June 1989: two more meters down June 1990: a total of 5 m lake lowering 1991: important ice avalanche causes impact wave, overtopping dam but no one killed May 1993: Start of tunnel construction

by 2 m June 1989: two more meters down June 1990: a total of 5 m lake lowering 1991: important ice

20 La construcción de túneles a través de la roca para bajar el nivel de la laguna Reynolds, Dolecki, Portocarrero Reynolds et al. (1998)

21 Labores de construcción del túnel en 1993 Reynolds et al. (1998)

23 Portocarrero

24 ALOS satellite images

25 W. Haeberli

26 Río Chucchún W. Haeberli

27 Lake probably shallow Lake probably deep Lake formation uncertain Lake formation ongoing or imminent Lake formation in coming decades W. Haeberli possible retention

28 Schneider et al., 2013 Multi-process modeling Ice avalanche lake impact flood/debris flow

29 Schneider et al., 2013 Hazard map Based on modeling and field work

30 Laguna 513: Monitoring and Early Warning Design and implementation of a GLOF early warning system Electricidad de paneles solar y comunicación de radio por cada estación necesario Cerro Aracoto: Estación repetidora con video camera y geófono para la observación de la Laguna 513 y los glaciares empinados del Nevado Hualcán Carhuaz: Centro de datos y comunicación para la observación y análisis de los datos (conectado al internet) Pampa Shonquil: Estación meteorológica con sensor de presión para medir el flujo de agua del Río Chucchun y geófono Schneider et al., 2013 Rampac Chico: Estación repetidora Alternativa: Cerro Marcash Leyenda: Conexión de radio Geófonos adicionales

31 Design and implementation of a GLOF early warning system

32 Conclusions: Succesfull hazard prevention: many lives saved Efficient risk reduction but not to zero Shift of hazard source to summit areas: polythermal (?) hanging glaciers and warm permafrost Larger events (10 6 m 3 ) and new lakes possible, hence further measures necessary: Observation of starting zone important (stabilisation/destabilisation?) Enhancement of freeboard (deeper tunnel, breach closure) Retention at Pampa de Shonquil (multipurpose structure) Passive measures in town (EWS, escape information)... and especially...

33 Conclusions: The probability of large catastrophes as a consequence of impact waves caused by rock/ice avalanches into lakes may appear small now but is rising with continued warming of icy mountain peaks and a growing number of lakes at their foot!

34 Giétro / Mauvoisin, 1818 Jahrbuch SAC XXXIV

35 Kantonsarchiv Wallis

36 Escher von der Linth

39 Alean, ca. 1985

40 Röthlisberger 1970

41 Röthlisberger 1970

43 Röthlisberger 1970

44 Röthlisberger 1970

46 Worni et al., 2012

47 Worni et al., 2012 Flow transformations

48 Dam breach / GLOF modeling Worni et al., 2012

49 Worni et al., in press Flow transformations

50 Unterer Grindelwaldgletscher Städelin, 2008

52 2. Juli Juli

53 June 2008 August October 2008

55 Bauliche Massnahmen Abflussstollen

56 Bauliche Massnahmen Abflussstollen

57 Hydrograph of lake outburst in May 2008 Bauliche Massnahmen Abflussstollen

58 Täsch Mattertal (VS) Weingartensee, Täsch, 2001

59 Typische Moränenbastion der Kleinen Eiszeit, bis 36 steil, Fels auf ca. 100m Tiefe, Freibord des Sees vor 2001 ca. 1-2 m

60 Huggel, Paul

62 Crealp

64 Bauliche Massnahmen See Philippe Teysseire

65 Täschalp, dam mitigation structures Bauliche Massnahmen Schutz/Ablenkungsdamm Täsch

66 Täsch, sediment retention reservoir

67 Wrap-up Täsch, sediment retention reservoir

Glacial hazards and downstream effects of climate change on high mountain glaciers. John M. Reynolds Reynolds Geo-Sciences Ltd, Mold, UK

Glacial hazards and downstream effects of climate change on high mountain glaciers John M. Reynolds Reynolds Geo-Sciences Ltd, Mold, UK Glacial hazards Hazard Description Time scale Avalanche Slide or