IASC Workshop
on the dynamics and mass
budget of Arctic glaciers
Abstracts
and Programme
IASC Workshop, 23-25 March 2015
Obergurgl (Austria)

IASC Network on Arctic Glaciology

IASC Workshop on the dynamics andmass budget of Arctic glaciers

Abstracts and program

IASC Workshop &Network on Arctic Glaciology annual meeting,23-25 March 2015, Obergurgl (Austria)

Organised by C.H. Tijm-Reijmer and M. Sharp

Network on Arctic Glaciology

Cover photo: South Greenland August 2014. Photo by J.E. Box.
ISBN: 978-90-393-6379-9

Contents
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4

Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5

Posters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8Participants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9Minutes of the Open Forum meeting . . . . . . . . . . . . . . . . . . . . . . .

10

Abstracts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

13

Scientific results and data from the Programme for Monitoring of the Greenland Ice Sheet (PROMICE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

13

A.P. Ahlstrøm, S.B. Andersen, D. van As, M. Citterio, R.S. Fausto, M.L. Andersen, J.E. Box, W.T. Colgan, M. Veicherts, H. Machguth, R. Forsberg, H. Skourup,
S.L.S. Sørensen, S.M. Hvidegaard, S.S. Kristensen, J. Dall, A. Kusk, D. Petersen

Ice thickness measurements and volume estimates for glaciers in Norway

13

L.M. Andreassen, M. Huss, K. Melvold, H. Elvehøy, S.H. Winsvold

Snow cover dynamics on a small polar glacier using high spatio-temporalmonitoring: 7 years of observations on Austre Lovén glacier. . . . . . . . . .

15

É. Bernard, J.M. Friedt, F. Tolle, S. Schiavone, M. GriselinComparison of century-plus Greenland ice surface mass balance reconstructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

15

J.E. Box, X. Fettweis, T. Kobashi

Using time lapse photogrammetry to examine spatial temporal variations
in Greenland outlet glacier dynamics . . . . . . . . . . . . . . . . . . . . . . . .

16

P.S. Christiansen, J.E. Box, A. Ahlstrøm, A. Messerli, A. Grinsted

Relationships between summer melt and winter motion at Kaskawulsh
Glacier, Yukon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

16

L. Copland, E. Herdes"Slow" surge of the Vavilov Ice Cap, Severnaya Zemlya . . . . . . . . . . . .

17

A. Glazovsky, I. Bushueva, G. Nosenko

Recent glacier and ocean changes in Northeast Greenland . . . . . . . . . .

18

G. Hamilton

Modeling the evolution of the Juneau Icefield using the Parallel Ice Sheet
Model (PISM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

19

F.A. Ziemen, R. Hock, A. Aschwanden, C. Khroulev, C. Kienholz, A. Melkonian,
J. Zhang

Application of terrestrial ’structure-from-motion’ photogrammetry on a mediumsize Arctic valley glacier: potential, accuracy and limitations . . . . . . . . . 19
B. Hynek, D. Binder, G. Boffi, W. Schöner, G. Verhoeven

The structural glaciology of Austre Brøggerbreen, northwest Svalbard . . .
S.J.A. Jennings, M.J. Hambrey, N.F. Glasser, B. Hubbard

1

20

Detailed investigation of glacier calving with a terrestrial radar interferometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

21

M. Luethi

Successive and intense melt rapidly decreases Greenland meltwater retention in firn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

21

H. Machguth, M. MacFerrin, D. van As, J.E. Box, C. Charalampidis, W. Colgan,
R.S. Fausto, H.A.J. Meijer, E. Mosley-Thompson, R.S.W. van de Wal

A comprehensive data base of glacier surface mass balance observations
from the ablation area of the ice sheet and the local glaciers of Greenland

22

H. Machguth, H.H. Thomsen, A. Weidick, J. Abermann, A. P. Ahlstrøm, M. L.
Andersen, D. van As, R.J. Braithwaite, C. E. Bøggild, J. Box, W. Colgan, R.S.
Fausto, K. Gleie, B. Hynek, H. Oerter, K. Steffen, M. Stober, R.S.W. van de Wal

Queen Elizabeth Island glacial surface elevation change from airborne altimetry 1995-2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

24

C. Mortimer, M. Sharp

Dissipative meltwater production in glaciers . . . . . . . . . . . . . . . . . . . .

25

J. Oerlemans

Calving of tidewater glacier driven by melting at the waterline . . . . . . . .

26

M. Pȩtlicki, M. Ciepły, J.A. Jania

Snow cover, ice loss, and rock debris quantification in an arctic glacierbasin through terrestrial laser scanning surveys . . . . . . . . . . . . . . . . .

27

A. Prokop, F. Tolle, É. Bernard, J.-M. Friedt, M. Griselin

Modeling the response of the Juneau Icefield to climate change . . . . . . .

27

A. Roth, R. Hock, B. Anderson, F. Ziemen

The use of airborne radar reflectometry to derive near-surface snow/firn
properties on Devon Ice Cap, Canadian Arctic . . . . . . . . . . . . . . . . . . .

28

A. Rutishauser, C. Grima, M. Sharp, D.D. Blankenship, D.A. Young, J.A. Dowdeswell

Investigating the dynamics of store glacier, west Greenland using UAVs .

29

J. Ryan, A. Hubbard, N. Toberg, P. Christoffersen, J. Box, N. Snooke

Firn line delineation using Envisat SAR imagery from 2005-2010 over Penny
Ice Cap, Baffin Island, Nunavut. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

30

N. Schaffer, L. Copland, C. Zdanowicz

A multivariate approach of the factors impacting a small arctic glacier . .

30

S. Schiavone, F. Tolle, É Bernard, J.-M. Friedt, M. Griselin, D. Joly

Revisiting "The Mass Balance of Circum-Arctic Glaciers and Recent Climate
Change" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

31

M. Sharp

The geodetic campaign 2014 for studies in mass balance, ice dynamics
and validation of satellite data in the Swiss Camp area, West Greenland .

32

M. Stober, H. Rott, M. Hönes, G. Grom, D. Floricioiu

Comparing the Geodetic and Glaciological mass budgets of White Glacier,Axel Heiberg Island, NU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
L. Thomson, L. Copland, M. Zemp

35

Dynamics and Changes in Extent of Bylot Island and Barnes Ice Caps,
Nunavut, Canada . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

36

W. Van Wychen, F. Delaney, L. Copland, D.O. Burgess, L. Gray

Cascading effects of sea ice losses on the formation and preservation of
tidewater glacier tongues and ice shelves on northern Ellesmere Island,
Nunavut, Canada . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

37

A. White, L. Copland

Capabilities of the Sentinel-1 SAR mission for operational monitoring of ice
sheets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
J. Wuite, T. Nagler, M. Hetzenecker, H. Rott38

Preface
The 2015 annual workshop and open forum meeting of the IASC Network on Arctic Glaciology took place in our favorite conference center, Obergurgl University
Center, Obergurgl, Austria. The combination of hotel and conference center in
one building, located in the beautiful Austrian Ötztal, staffed by very friendly andhelpfull people makes this a perfect place for our workshop.
The 2015 meeting attracted 35 participants from 12 different countries. The
IASC Cryosphere Working Group generously supported our meeting which included
support of eleven young scientists to attend the meeting. These 35 participantspresented cutting edge science in 22 talks and 7 posters. The open forum meeting provided many ideas to initiate as a community. An overview of the meeting,especially abstracts of the presented work, can be found in this book.
The activities are not limited to the conference room, but extent, as always, tothe skiing slopes around the conference facility. On the slopes and afterwards inthe bar, the discussions related to, amongst others, science and fieldwork continued resulting in once again a succesful and informal event. Next year the meeting
will take place in Benasque, Spain, from 25 - 27 January, 2016. I hope to meet you
all there.
C.H. Tijm-Reijmer
June 2015

4

Program
The meeting will take place in the University Center Obergurgl, Austria.
Note: Coffee breaks are included in the conference fee, lunches not.
Those participants not staying at the University Center can join dinner at thecenter. To join: register and pay (AC29,- per diner) at the front desk of the center
before noon.

Monday 23 March
08:30 - 09:00

Registration

Convener:

Carleen Reijmer

09:00 - 09:10

Welcome C.H. Reijmer

09:10 - 09:30

Capabilities of the Sentinel-1 SAR mission for operational
monitoring of ice sheets Jan Wuite, T. Nagler, M. Hetzenecker,
H. Rott

09:30 - 09:50

The geodetic campaign 2014 for studies in mass balance, ice
dynamics and validation of satellite data in the Swiss Camparea, West Greenland Manfred Stober, H. Rott, M. Hönes, G.
Grom, D. Floricioiu

09:50 - 10:10

Recent glacier and ocean changes in Northeast Greenland
Gordon Hamilton

10:10 - 10:30

Calving of tidewater glacier driven by melting at the waterline
Michał Pȩtlicki, M. Ciepły, J.A. Jania

10:30 - 11:00

Coffee break

Convener:

Gordon Hamilton

11:00 - 11:20"Slow" surge of the Vavilov Ice Cap, Severnaya Zemlya Andrey
Glazovsky, I. Bushueva, G. Nosenko

11:20 - 11:40

Detailed investigation of glacier calving with a terrestrial radar
interferometer Martin Luethi

11:40 - 12:00

Poster presentations by authors

12:00 -

Very Long Lunch

18:30 -

DinnerTuesday 24 March
Convener:

Andreas Ahlstrøm

5

09:00 - 09:20

The use of airborne radar reflectometry to derive near-surface
snow/firn properties on Devon Ice Cap, Canadian Arctic Anja
Rutishauser, C. Grima, M. Sharp, D.D. Blankenship, D.A. Young,
J.A. Dowdeswell

09:20 - 09:40

Successive and intense melt rapidly decreases Greenland
meltwater retention in firn Horst Machguth, M. MacFerrin, D.
van As, J.E. Box, C. Charalampidis, W. Colgan, R.S. Fausto, H.A.J.
Meijer, E. Mosley-Thompson, R.S.W. van de Wal

09:40 - 10:00

Snow cover dynamics on a small polar glacier using highspatio-temporal monitoring: 7 years of observations on Austre
Lovén glacier. Éric Bernard, J.M. Friedt, F. Tolle, S. Schiavone,M. Griselin

10:00 - 10:20

Firn line delineation using Envisat SAR imagery from 2005-2010
over Penny Ice Cap, Baffin Island, Nunavut Nicolle Schaffer, L.
Copland, C. Zdanowicz

10:20 - 10:50

Coffee break

Convener:

Florian Tolle

10:50 - 11:10

Ice thickness measurements and volume estimates for glaciersin Norway Liss Andreassen, M. Huss, K. Melvold, H. Elvehøy,
S.H. Winsvold

11:10 - 11:30

Queen Elizabeth Island glacial mass loss from airborne altimetry
1995-2012 Colleen Mortimer, M. Sharp

11:30 - 11:50

Application of terrestrial ’structure-from-motion’photogrammetry on a medium-size Arctic valley glacier:potential, accuracy and limitations Bernhard Hynek, D. Binder,
G. Boffi, W. Schöner, G. Verhoeven

11:50 - 12:10

Dissipative meltwater production in glaciers Hans Oerlemans

12:10 - 15:30

Very Long Lunch

15:30 - 16.30

Coffee break and POSTER SESSION

16:30 - 18:00

IASC Network on Arctic Glaciology Open Forum meeting C.H.
Reijmer / M. Sharp

18:30 -

DinnerWednesday 25 March
Convener:

Liss Andreassen

09:00 - 09:20

Scientific results and data from the Programme for Monitoring of
the Greenland Ice Sheet (PROMICE) Andreas Ahlstrøm, S.B.
Andersen, D. van As, M. Citterio, R.S. Fausto, M.L. Andersen, J.E.
Box, W.T. Colgan, M. Veicherts, H. Machguth, R. Forsberg, H.
6

Skourup, S.L.S. Sørensen, S.M. Hvidegaard, S.S. Kristensen, J.
Dall, A. Kusk, D. Petersen
09:20 - 09:40

Comparing the Geodetic and Glaciological mass budgets ofWhite Glacier, Axel Heiberg Island, NU Laura Thomson, L.
Copland, M. Zemp

09:40 - 10:00

A multivariate approach of the factors impacting a small arctic
glacier Sophie Schiavone, F. Tolle, É Bernard, J.-M. Friedt, M.
Griselin, D. Joly

10:00 - 10:20

Revisiting "The Mass Balance of Circum-Arctic Glaciers andRecent Climate Change" Martin Sharp

10:20 - 10:50

Coffee break

Convener:

Horst Machguth

10:50 - 11:10

Modeling the evolution of the Juneau Icefield using the ParallelIce Sheet Model (PISM) F.A. Ziemen, Regine Hock, A.
Aschwanden, C. Khroulev, C. Kienholz, A. Melkonian, J. Zhang

11:10 - 11:30

Modeling the response of the Juneau Icefield to climate change
Aurora Roth, R. Hock, B. Anderson, F. Ziemen

11:30 - 11:50

Comparison of century-plus Greenland ice surface mass balancereconstructions Jason Box, X. Fettweis, T. Kobashi

11:50 - 12:10

Relationships between summer melt and winter motion at
Kaskawulsh Glacier, Yukon Luke Copland, E. Herdes

12:10 - 12:20

Final words C.H. Reijmer / M. Sharp

12:20 -

Lunch / Departure / Skiing

19:00 -

(Dinner)7

Posters• Using time lapse photogrammetry to examine spatial temporal variations inGreenland outlet glacier dynamics Philip Christiansen, J.E. Box, A. Ahlstrøm,
A. Messerli, A. Grinsted• The structural glaciology of Austre Brøggerbreen, northwest Svalbard
Stephen Jennings M.J. Hambrey, N.F. Glasser, B. Hubbard• A comprehensive data base of glacier surface mass balance observations fromthe ablation area of the ice sheet and the local glaciers of Greenland Horst
Machguth, H.H. Thomsen, A. Weidick, J. Abermann, A.P. Ahlstrøm, M.L.
Andersen, D. van As, R.J. Braithwaite, C.E. Bøggild, J. Box, W. Colgan, R.S.
Fausto, K. Gleie, B. Hynek, H. Oerter, K. Steffen, M. Stober, R.S.W. van de Wal• Snow cover, ice loss, and rock debris quantification in an arctic glacier basinthrough terrestrial laser scanning surveys Alexander Prokop, F. Tolle, É.
Bernard, J.-M. Friedt, M. Griselin• Investigating the dynamics of Store Glacier, West Greenland Using UAVS
Jonathan Ryan, A. Hubbard, N. Toberg, P. Christoffersen, J. Box, N. Snooke• Dynamics and Changes in Extent of Bylot Island and Barnes Ice Caps, Nunavut,
Canada Wesley Van Wychen, F. Delaney, L. Copland, D.O. Burgess, L. Gray
• Cascading effects of sea ice losses on the formation and preservation of
tidewater glacier tongues and ice shelves on northern Ellesmere Island,
Nunavut, Canada Adrienne White, L. Copland8

Participants
1. Andreas Peter Ahlstrøm (apa@geus.dk)
2. Liss Andreassen (lma@nve.no)
3. Éric Bernard (eric.bernard@univ-fcomte.fr)
4. Jason Box (jeb@geus.dk)
5. Philip Sigaard Christiansen* (tkw904@alumni.ku.dk)
6. Luke Copland (luke.copland@uottawa.ca)
7. Andrey Glazovsky (glazovsky@gmail.com)
8. Gordon Hamilton (gordon.hamilton@maine.edu)
9. Regine Hock (rehock@alaska.edu)
10. Bernhard Hynek* (bernhard.hynek@zamg.ac.at)
11. Stephen Jennings (saj7@aber.ac.uk)
12. Georg Kaser (Georg.Kaser@uibk.ac.at)
13. Michael Kuhn (Michael.Kuhn@uibk.ac.at)
14. Martin Luethi (martin.luethi@geo.uzh.ch)
15. Horst Machgut (homac@byg.dtu.dk)
16. Michael Mayer (mima@univie.ac.at)
17. Colleen Mortimer* (cmortime@ualberta.ca)
18. Lindsey Nicholson (lindsey.nicholson@uibk.ac.at)
19. Friedl Obleitner (friedrich.obleitner@uibk.ac.at)
20. Hans Oerlemans (J.Oerlemans@uu.nl)
21. Michał Petlicki* (petlicki@igf.edu.pl)
22. Alexander Prokop (alexander.prokop@boku.ac.at)
23. Aurora Roth* (rothaurora@gmail.com)
24. Anja Rutishauser* (anjarutishauser@bluewin.ch)
25. Johnny Ryan* (jor44@aber.ac.uk)
26. Nicole Schaffer* (nicole.schaffer@uottawa.ca)
27. Sophie Schiavone* (sophie.schiavone@univ-fcomte.fr)
28. Martin Sharp (martin.sharp@ualberta.ca)
29. Manfred Stober (manfred.stober@hft-stuttgart.de)
30. Laura Thomson* (lthom021@uOttawa.ca)
31. Carleen Tijm-Reijmer (c.h.tijm-reijmer@uu.nl)
32. Florian Tolle (florian.tolle@univ-fcomte.fr)
33. Wesley van Wychen* (wvanw046@uottawa.ca)
34. Adrienne White* (awhit059@uottawa.ca)
35. Jan Wuite (Jan.Wuite@enveo.at)(Young scientists receiving support are marked *).

9Minutes of the Open Forum meeting
Chair: Carleen Tijm-Reijmer
Vice Chair: Martin Sharp
Minutes: Lindsey Nicholson
Invited to attend: all participants of the workshop.
Agenda
1.
2.
3.
4.
5.
6.
7.
8.

Other items for the agenda
Background on IASC and NAG
Meeting minutes 2016
Location IASC-NAG workshop
Network activities
National contacts
Extended Abstracts
Anything else

Ad. 1
No additional items for the agenda.
Ad. 2
Short Introduction to International Arctic Science Committee (IASC):- Background to IASC (not IACS!)- IASC has 5 working groups- NAG can cross cut the IASC working groups- Need to demonstrate Network activity to ensure funding and support
Ad. 3
An overview was given about what was discussed last year.
Ad. 4
Location for future meetings: - 2016 in Spain Benasque- In Gran Hotel Benasque (***): conference room and hotel at same location,
cheaper accomodation available nearby.
- No objections to 2016 decision- Risk involved in needing to meet an unspecified minimum attendance- No objections to 2017 plan is to go to N. America- Appeal for suggestions for locations for 2017: no suggestions given.
Extra information since the meeting:Meeting dates for 2016 are now set at: Monday 25 - Wednesday 27 January 2016.

10

Ad. 5
Overview of topics discussed last year and activities related to them:- Tidewater glacier initiative (Joined activity IASC Cryospheric Working group and
NAG)* Workshop on ’Glacier and ice-stream calving: Observations and Modelling’ wasorganized in Grenoble, France (2-3 June 2014).
* All presentations, talks and discussions are available online* Review paper being written on tidewater glacier dynamics is being written to besubmitted to Reviews Geophysics- The ’IMBIE’ like project for small ice caps: GIC-IMBIE* Discussed first 2 years ago as a possible initiative but so far has not really beentaken up by anyone.
Extra information since the meeting: The idea is taken up again by making a plan
for a small workshop to bring together people who can take this further.
- Firn processes* Subject well suitable to take up as a comunity. * Jason Box already involved in aworkshop to be organised in spring 2016.
* Can we include NAG in Jason’s initiative?
- Arctic glaciers mass balance records (MAGICS). * Goal is to extent the data sets
gathered by NAG in the MAGICS project to present, by Martin Sharp. * Extended
this record since 1997 (up to 1994 data). Now updated to 2013.
* Focussed on long term records.
* Found errors in WGMS, will update them
* New analysis draws new conclusions compared to the 1997 report (presented
by Martin Sharp in this meeting)* Plan to update the website with this extended dataset
Suggestions for new focus areas:- Regine Hock:
Global comparison of mass balance models, Little effort for big gain
Comment Martin Sharp: data check would be required and may be inadequate- Gordon Hamilton
Greenland icesheet and ocean working group (GRISO) (http://web.whoi.edu/griso/)Workshop in 2013: Extended from this workshop with focus on understanding GIS
dynamics
1) improved bathymetry through data mining
2) surface runoff → subglacial → grounding line controls3) GIS ocean interaction observing system
Anyone can propose an additional focus topic, it should be community led
Comment Carleen Tijm-Reijmer: how to connect it to NAG?
Answer Gordon Hamilton: GRISO affiliated to CliC so can make a focus session in
next NAG meeting
Comment Carleen Tijm-Reijmer: advantage of getting involved in ocean connections

11

Comment Gordon Hamilton: advantage to learn from non GIS analogues/locations- Carleen Tijm Reijmer
UAV (unmanned aerial vehicle) applications to NAG
Is it worth having a half day of NAG dedicated to this?
Comment Andreas Alstrøm: does it overlap other technical workshops, or is there
a good idea to have an additional specific practical workshops
Comment Carleen Tijm-Reijmer: possibility to run meetings back-to-backComment Liss Andreassen: also using UAVs in Iceland (Jarosch) and Norway (Andreasson/Immerzeel), so can be a useful NAG developement
Conclusion Carleen Tijm-Reijmer: a useful addition to next years program
Ad. 6
No changes in National contacts. Attempt to activate them more.
Ad. 7
Abstracts:- Published as .pdf online on NAG website- Deadline for extended abstracts 12 May 2015
- Published as pdf 01 Aug 2015
- Michael Kuhn offers to publish abstracts in Zeitschrift für Gletscherkunde und
Glazialgeologie (ZGG) (ISBN, no impact factor). Challenge is that to be publishedin the year of the meeting would require the abstracts to fill 80 pages- Can make room for extended abstracts and include figures- Review of abstracts would be carried out primarily by NAG Meeting attendees- No charge for publication, but optional charges A
C260 for 16 color pages- ±50% group is interested in this
- ZZG option would not be available online- Publication date of December 2015 requires deadline of June 2015
- Additional online access is not clear, MK will check this
- Luke Copland and Carleen Tijm-Reijmer stated preference for online access
Extra information since the meeting:This year the abstracts will not be published in ZGG. In case we decide to do this,it should be announced with the meeting announcement so participants are awareof this.

12

Abstracts
Scientific results and data from the Programme for Monitoring of the Greenland Ice Sheet (PROMICE)
A.P. Ahlstrøm1 , S.B. Andersen1 , D. van As1 , M. Citterio1 , R.S. Fausto1 , M.L. Andersen1 ,J.E. Box1 , W.T. Colgan1 , M. Veicherts1 , H. Machguth2 , R. Forsberg3 , H. Skourup3 , S.L.S.
Sørensen3 , S.M. Hvidegaard3 , S.S. Kristensen3 , J. Dall3 , A. Kusk3 , D. Petersen4
1 GEUS - Geological Survey of Denmark and Greenland, Copenhagen Denmark
2 DTU Artek - Arctic Technology Centre, Kemitorvet, Lyngby, Denmark
3 DTU Space - National Space Institute, Elektrovej, Lyngby, Denmark
4 ASIAQ - Greenland Survey, Nuuk, Greenland

Recent scientific and data contributions from the Programme for Monitoring of theGreenland Ice Sheet (PROMICE) include an estimate of Greenland ice sheet massloss partioned in SMB/frontal ablation for each major basin, an improved icemask
based on aerial photos, comparison of RCM runoff against observed discharge, a
new comprehensive database of historical mass balance measurements in Greenland, airborne measurements of elevation and ice thickness over the entire ice
sheet margin, as well as a freely available, long, stable and well-documented timeseries of measurements from an AWS network in the ablation zone. Other products include satellite-derived ice velocity maps from the ice-sheet -wide marginalzone and GPS velocity time series from selected outlet glaciers. These recent
results and available datasets will be presented in an overview, including the instrumental development of the PROMICE AWS which is now made to order.

Ice thickness measurements and volume estimates for
glaciers in Norway
L.M. Andreassen1 , M. Huss2,3 , K. Melvold1 , H. Elvehøy1 , S.H. Winsvold1,4
1 Norwegian Water Resources and Energy Directorate, NVE, Oslo, Norway
2 Department of Geosciences, University of Fribourg, Fribourg, Switzerland

3 Laboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zurich, Zurich, Switzerland
4 Department of Geosciences, University of Oslo, Oslo, Norway

Glacier volume and ice thickness distribution are important variables for the water resources management in Norway and for the assessment of future glacierchanges. Since the 1980s ice thickness measurements have been carried out
by radio-echo sounding (RES) on many glaciers in Norway. Measurements wereconducted on smaller mountain glaciers as well as on the largest ice caps. So
far, however, a total ice volume estimate for Norway has not yet been derived
from these data. Here, we provide an overview of ice thickness measurements
available for mainland Norway, use a distributed model to interpolate data and to
derive an ice volume estimate for all individual Norwegian glaciers, and compare
measured ice volume with results from various volume-area scaling relations.
13

Figure 1. Location map of glaciers with ice thickness measurements in Norway used in this study.
Insets show southern Norway (1), Svartisen (2), Blåmannsisen (BLÅ) and Langfjordjøkelen (LAJ).
Glaciers with ice thickness measurements are in blue, others in grey. Numbers refer to glacier ID
and letters to glacier complex code (Andreassen et al., 2012).

We used all ice thickness data that were available in digital format (Fig. 1). The
source of the data is NVE’s database with a few additions from collaborators. Information on the data collection and processing is documented in individual reports
and papers (Andreassen et al., 2015). Glacier outlines from a Landsat-derived inventory from 1999-2006 covering an area of 2692 ± 81 km2 were used as input(Andreassen et al., 2012). We compiled a rich set of ice thickness observations
collected over the last thirty years. Altogether, interpolated ice thickness measurements were available for 870 km2 , or 32%, of the current glacier area of
Norway with a total ice volume of 134 ± 23 km3 . Ice thickness data were used
to calibrate a physically-based distributed model (Huss and Farinotti, 2012) for
estimating ice thickness of unmeasured glaciers. The results were also used tocalibrate volume-area scaling relations and revealed that scaling was sensitive
to the dividing of glacier complexes into units and to the sample of measured
glaciers. The calibrated total volume estimates for all Norwegian glaciers ranged
from 257 to 300 km3 .
References
Andreassen, L.M., M. Huss, K. Melvold, H. Elvehøy and S.H. Winsvold, 2015. Ice thickness measurements and volume estimates for glaciers in Norway. J. Glaciol., Accepted.
Andreassen, L.M., S.H. Winsvold (eds.), F. Paul and J.E. Hausberg, 2012. Inventory of Norwegianglaciers. NVE Report 38, 236pp. (available at: www.nve.no/glacier)Huss, M., and D. Farinotti, 2012. Distributed ice thickness and volume of all glaciers around theglobe. J. Geophys. Res., 117(F04010 ). doi:10.1029/2012JF002523.

14

Snow cover dynamics on a small polar glacier using
high spatio-temporal monitoring: 7 years of observations on Austre Lovén glacier.
É. Bernard1 , J.M. Friedt2 , F. Tolle1 , S. Schiavone1 , M. Griselin1
1 ThéMA, université de Franche-Comté, Besançon, France
2 FEMTO-ST, université Franche Comté, Besançon, France

Arctic glaciers are known to be reliable indicators of global climate changes as
their behaviour are strongly linked to it. Within this context, the observed evolutions are becoming faster and more unpredictable. Snow and ice dynamics are
directly affected, and following processes becomes challenging: some fast but
key events can be missed since they are short but significant.
In order to better understand these processes, Austre Lovén glacier (4.5 km2 ),located on the Brøgger peninsula (78◦ N, Spitsbergen) has been systematically
instrumented and monitored since 2007. Air temperatures have been recorded
continuously through a network of 20 sensors distributed on the whole glaciersurface. Hourly temperature is thus available and can be spatialized by interpolating data: this gives the thermal state of the glacier. Moreover, with the aimof observing the most accurately snow cover dynamics and melt water phenomena, 6 automatic photos stations were installed around the glacier basin so as
to cover the largest area. Geometric corrections of the photos, using reference
points located on the glacier using GPS receivers, yield quantitative informationfrom initially qualitative images. Projecting the resulting mosaic on a GIS allows
for the precise monitoring of ice-related processes, and especially the snow coverage evolution over time.
This work is based on seven years of observations. By crossing temperature
data with the glacier cover typology (binary snow or ice), we can estimate accurately the potential of snow/ice melting. This is established by applying a kcoefficient in degree-day model. Thus, cumulative maps of potential melt water
allows to assess the protection of snowcover and how warm summers could bedestructive if the glacier is not or not enough covered by snow.

Comparison of century-plus Greenland ice surface massbalance reconstructions
J.E. Box1 , X. Fettweis, T. Kobashi
1 GEUS - Geological Survey of Denmark and Greenland, Copenhagen Denmark

This presentation focuses on a comparison of Greenland ice surface mass balancereconstructions for the past century-plus. Comparisons are made among reconstructions and versus ice cores, meteorological station temperature series, andborehole temperature inversions. The compared reconstructions include that from
Box (2013) based on in-situ observations and that from the regional climate model
MAR v3.5.0 driven by 1.) the 1871-2012 NOAA 20th Century Re-analysis (NOAA
15

20CR) and by 2.) the 1900-2010 ECMWF ERA-20C as well as MAR v3.5.2 forced
by ERA-20C (respectively NOAA 20CR) with a temperature correction of +1◦ C (respectively -1◦ C) to the MAR boundary conditions given that ERA-20C (respectively
20CR) is ∼1◦ colder (respectively. warmer) over Greenland than ERA-Interim dataover 1980-2010. By comparison with 20CR, ERA-20C is not an ensemble mean
which may be advantageous for forcing regional models. Indeed, part of the MAR20CR accumulation increase is due to the decrease of the spread in 20CR and thenits is due to an apparent increase of the pressure gradient at the MAR boundaries
which impacts the humidity advection and then precipitation amount in MAR.
References
Box, J. E., 2013. Greenland ice sheet mass balance reconstruction. Part II: Surface mass balance(1840-2010). J. Climate, 26(18), 6974-6989. doi:10.1175/JCLI-D-12-00518.1.

Using time lapse photogrammetry to examine spatial
temporal variations in Greenland outlet glacier dynamics
P.S. Christiansen, J.E. Box, A. Ahlstrøm, A. Messerli, A. Grinsted
GEUS - Geological Survey of Denmark and Greenland, Copenhagen Denmark

Using time lapse photogrammetry, several outlet glaciers at the Greenland ice
sheet are monitored in order to evaluate the sensitivity of the glacier motion todifferent forcings such as: surface melting, calving, ocean tides, basal melting andothers. Knowing the sensitivity is desirable as the discharge from outlet glaciers,
and thereby the mass loss of the Greenland ice sheet, depends on the surface
velocity.
Beginning in 2007, cameras were placed at the outlet glaciers as a part of the
The Extreme Ice Survey. The velocity field of the glaciers is measured from repeated photos using the newly developed open source feature-tracking software
ImGRAFT. By examining time lapse sequences from different glaciers over single
years and interannually, this study examines the spatial and temporal variationsof glacier motion. The study incorporates records of land and sea surface temperature, sea ice concentration, and tides, to interpret glacier velocity variations.

Relationships between summer melt and winter motion
at Kaskawulsh Glacier, Yukon
L. Copland, E. Herdes
Department of Geography, University of Ottawa, Ottawa, Canada

A near-continuous 5 year record of velocities measured with 4 differential GPS(dGPS) units along the Kaskawulsh Glacier reveals marked inter-annual and intraannual variations in motion. Shortly after the onset of melt each spring there is16

a rapid acceleration of the glacier, with velocities increasing up to triple above
winter values. The acceleration starts near the glacier terminus and propagates
upglacier over the space of a week or so. Enhanced motion continues throughout
the summer, and then rapidly drops once melt stops in the early fall. Velocities in
the fall and winter are low, but quite variable between years, with a strong inverse
connection between the amount of summer melt and fall/winter motion. In some
winter months, for example, motion is >30% slower at all dGPS stations after asummer with high melt (>5 m), in comparison to a summer with low melt (<3m). This suggests that a negative feedback process may operate on large alpine
glaciers which reduces their velocity response to increased melt under a warming
climate.

"Slow" surge of the Vavilov Ice Cap, Severnaya Zemlya
A. Glazovsky, I. Bushueva, G. Nosenko
Institute of Geography, Russian Academy of Sciences, Moscow, Russsia

We use satellite imagery (1963- 2015) and airborne radar data (September 2014)
to document rapid acceleration and surge of western sector of the Vavilov ice cap,
Severnaya Zemlya.
In the 1960s-70s, the ice margin there was stable and followed the generalsmooth outline. Only slight advance by 80 meters in average occurred in thisdecade. Thereat the margin was land-terminated and separated from sea by rampart of "dead" sediment-laden ice up to 0.5 km width.

Figure 1. Surge of the Vavilov Ice Cap, Severnaya Zemlya, 15 September 2014 (by A. Glazovsky).

In 1980s- 2000s the margin began to bulge towards the sea with mean rate
70 m a1 , so that in 2012 the outlet lobe of 2.4 km length, 8 km width, and 12.36
km2 area was formed. When advancing it pushed forward the "dead" ice belt thatframed the front.
17

In 2012, the protrusion of front dramatically accelerated: rate of advance increased from 180 to 1540 m a1 (maximum up to 2.4 km a1 ).
In September 2014 the area enlargement rate reached 37 000 m2 d1 .The surging lobe with 3.142 km3 of ice occupied an area of 30.14 km2 , and embossed
into the sea by 4.5 km. Its thickness reached 178 m (104 m mean), with bedrockat average depth -40 m (minimum -67 m) below sea level. The framing rampartalmost completely collapsed; the margin spread and spitted into fingers, but, nevertheless, it advanced further by February 2015. Only shallows waters seems toprevent the major eruption of icebergs and front destruction. Radarograms show
no large barriers or overdeepenings on bedrock, but reveal a feature that might
be remains of marginal structure of 1963, also traceable through ice on imagery.
Possibly, it is the roots of the cold-based plugging belt that was in most part cut off
and pushed to the sea, where ice movement accelerated on soft unfrozen marine
sediments.

Recent glacier and ocean changes in Northeast Greenland
G. Hamilton
University of Maine

The northeastern sector of Greenland has so far not experienced the profoundseries of changes observed elsewhere around the margin of the ice sheet. One
explanation is the relatively cold ocean waters of the Fram Strait, far removed
from the warming waters of the subpolar gyre that are hypothesized to have provided the forcing for the changes observed elsewhere. We discuss recent results
which suggest this relatively stable situation might not persist.
The Northeast Greenland Ice Stream (NEGIS) is the dominant feature in this
sector of the ice sheet. It feeds ice from the interior into three marine-terminating
glaciers: Nioghalvfjerdsfjorden (79N), Zachariae Isstrøm (ZI), and Storstrømmen.
NEGIS sits in a trough that is below sea level far inland of the current grounding line, making is particularly susceptible to rapid retreat and dynamic thinning.
ZI recently lost its floating tongue in 2013 and ice speeds at the grounding line
have increased. The much larger floating tongue of 79N (the largest ice shelf inthe northern hemisphere) remains intact, but an updated balance assessment indicates a ∼35% increase in submarine melt rate from 1998 to 2012. Increased
melting might be the result of a slight warming (∼1◦ C) of waters circulating in the
sub-ice cavity.
Additional evidence for changes in the ocean environment comes from an analysis of the Norske Ø Ice Barrier (NØIB), an extensive region of perennially fast
ice abutting the terminus of 79N. NØIB varies in size from year to year but, until recently, complete breakups were a rare event. It reportedly broke up in the
1950s and was observed to breakup in August, 1997. More recently, the NØIBdisintegrated during the summers of 2001-2005, 2008, and 2010-2014. A statistical analysis indicates that June surface air temperatures and regional cyclones
are good predictors of the NÃŸIB breakup but warming ocean waters circulating
benath the ice barrier are probably also involved.
18Modeling the evolution of the Juneau Icefield using theParallel Ice Sheet Model (PISM)
F.A. Ziemen1 , R. Hock1 , A. Aschwanden1 , C. Khroulev1 , C. Kienholz1 , A. Melkonian2 , J.
Zhang3
1 Geophysical Institute, University of Alaska Fairbanks, Fairbanks, Alaska, USA
2 Earth and Atmospheric Sciences Department, Cornell University, Ithaca, NY, USA

3 Department of Physics, and Department of Energy and Environmental Systems, North Carolina

Agricultural and Technical State University, Greensboro, NC, USA

Here we study the evolution of the Juneau Icefield, one of the largest icefields inNorth America (4149 km2 ), using the Parallel Ice Sheet Model (PISM). We test two
climate data sets of air temperature and precipitation; the first was dynamicallydownscaled by the Weather Research and Forecasting Model (WRF) and the second is based on spatial interpolation of the Climate Research Unit (CRU) global
reconstruction by the Scenarios Network for Alaska Planning (SNAP). Good agreement between simulated and observed surface mass balance could only be foundafter substantially adjusting WRF precipitation to account for orographic effects
while SNAP’s precipitation pattern is incompatible with observations of surface
mass balance. By 2100 the model projects a decrease in ice volume by 58% to
68% and a 57-63% area loss compared to 2010. Under current (1971-2010) climate the icefield reaches an equilibrium state after roughly 200 years at 86% of
the 2010 volume. Repeating the 2070-2099 climate beyond the 21st century almost eliminates the icefield within by 2200, while stabilizing the climate earlier
causes the icefield to reach a new equilibrium after several 100 years, althoughat substantially reduced ice volumes. If all ice was removed, under current climate conditions, the icefield would regrow to a similar volume as if the model
was started with current initial ice volume. Despite large projected volume losses,
the complex high-mountain topography makes the Juneau Icefield less susceptible
to climate warming than other Alaskan low-lying icefields and allows for multiple
retreat states under varying climate conditions.

Application of terrestrial ’structure-from-motion’ photogrammetry on a medium-size Arctic valley glacier:potential, accuracy and limitations
B. Hynek1 , D. Binder1 , G. Boffi2 , W. Schöner1 , G. Verhoeven3
1 Zentralanstalt für Meteorologie und Geodynamik, Wien, Austria
2 Institute for Geodesy and Photogrammetry, ETH Zurich, Switzerland

3 Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology, Wien, Austria

Terrestrial photogrammetry was the standard method for mapping high mountainterrain in the early days of mountain cartography, until it was replaced by aerial
photogrammetry and airborne laser scanning. Modern low-price digital single-lensreflex (DSLR) cameras and highly automatic and cheap digital computer vision
software with automatic image matching and multiview-stereo routines suggest

19the rebirth of terrestrial photogrammetry, especially in remote regions, where airborne surveying methods are expensive due to high flight costs. Terrestrial photogrammetry and modern automated image matching is widely used in geodesy,
however, its application in glaciology is still rare, especially for surveying ice bodies at the scale of some km2 , which is typical for valley glaciers.
In August 2013 a terrestrial photogrammetric survey was carried out on Freya
Glacier, a 6 km2 valley glacier next to Zackenberg Research Station in NE-Greenland, where a detailed glacier mass balance monitoring was initiated during thelast IPY. Photos with a consumer grade digital camera (Nikon D7100) were takenfrom the ridges surrounding the glacier. To create a digital elevation model, thephotos were processed with the software photoscan. A set of 100 dGPS surveyed
ground control points on the glacier surface was used to georeference and validate
the final DEM.
Aim of this study was to produce a high resolution and high accuracy DEM of theactual surface topography of the Freya glacier catchment with a novel approachand to explore the potential of modern low-cost terrestrial photogrammetry combined with state-of-the-art automated image matching and multiview-stereo routines for glacier monitoring and to communicate this powerful and cheap method
within the environmental research and monitoring community.

The structural glaciology of Austre Brøggerbreen, northwest Svalbard
S.J.A. Jennings, M.J. Hambrey, N.F. Glasser, B. Hubbard
Centre for Glaciology, Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth, UK

Many glaciers in Svalbard have receded and thinned substantially from their Neoglacial maximum c. 1900 AD. Thinning of Austre Brøggerbreen, a predominantly
cold-based valley glacier located in northwest Spitsbergen, has revealed the former internal structure of the glacier in remarkable detail. From this, changes in
the glacier’s dynamics can be inferred in a way that is applicable to other valley
glaciers that are receding rapidly. Detailed structural mapping of Austre Brøggerbreen from aerial photography (NERC imagery acquired in summer 2004) has
enabled the formation and evolution of different suites of structures to be documented. The glacier comprises multiple broad accumulation basins that coalesce
into a narrow and comparatively short tongue. Despite not being very dynamic
at present, the structure of Austre Brøggerbreen is dominated by fractures thatoriginated high in the glacier’s accumulation area, indicating that the glacier was
substantially more dynamic during the Neoglacial time than at present. Furthermore, the persistence of these fractures through the ablation zone to the glacier’s
terminus indicates that they initially penetrated to great depths, possibly all theway to the glacier’s bed. Individual suites of fractures are usually contained
within discrete flow units, with transverse fractures becoming increasingly arcuate
down-glacier as a result of ductile flow. In two cases, initially transverse fracturesets have become sufficiently reorientated at flow-unit boundaries to develop afracture-derived longitudinal foliation. The results of this study provide a unique

20

view of the internal structure of a Svalbard valley glacier, and illustrate how reorientation of relict fracture sets can lead to the formation of a new fracture-derived
longitudinal foliation.

Detailed investigation of glacier calving with a terrestrial radar interferometer
M. Luethi

We investigate ice dynamic processes related to glacier calving with a terrestrial
radar interferometer (TRI), and complementary well established methods. The
target glacier, Eqip Sermia, West Greenland, is a small tidewater outlet glacierof the Greenland Ice Sheet which recently accelerated and started to retreat at
high rate. The glacier is calving several times per day with occasional large calving events that lead to tsunamis in the embayment. TRI measurements allow
us to obtain displacement fields and DEMs in minute intervals, thus facilitating
the determination of calving volumes and tsunami waves of big calving events.
From the displacement fields we can extract strain rates which are essential forunderstanding of the fracture processes of crevassing preceding glacier calving.

Successive and intense melt rapidly decreases Greenland meltwater retention in firn
H. Machguth1,2 , M. MacFerrin3 , D. van As2 , J.E. Box2 , C. Charalampidis2,4 , W. Colgan2 ,R.S. Fausto2 , H.A.J. Meijer5 , E. Mosley-Thompson6 , R.S.W. van de Wal7
1 Centre for Arctic Technology, Technical University of Denmark, Denmark
2 Geological Survey of Denmark and Greenland GEUS, Copenhagen, Denmark3

Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado,
Boulder, USA
4 Department of Earth Sciences, Uppsala University, Uppsala, Sweden
5 Centre for Isotope Research (CIO), Energy and Sustainability Research Institute Groningen (ESRIG),
University of Groningen, the Netherlands
6 Department of Geography, Ohio State University, Columbus, USA
7 Institute for Marine and Atmospheric Research Utrecht (IMAU), Utrecht University, the Netherlands

About half of the current mass loss of the Greenland ice sheet is attributed torunoff from surface melt. At higher elevations, however, melt does not automatically equal runoff, because meltwater refreezes in the porous near-surface snow
and firn. Recent studies suggest that all or most firn pore space is available formeltwater storage, which would make the firn an important buffer against Greenland’s surface melt contribution to sea level rise.
Here, we challenge the notion that all firn pore space is available for meltwater
retention based on field observations (Fig. 1), analysed in the context of historicallegacy data. Our observations frame the recent exceptional melt summers of theyears 2010 and 2012 and reveal a distinctive pathway of firn changes induced bysuccessive and intensive melt. At the lower end of the pathway, where melt ismost abundant, porous firn loses its capability to retain meltwater.
21

Figure 1. Stratigraphy of the nine major firn cores drilled in late April to mid May 2013. Ice lenses
are in blue and given at 1 cm vertical resolution. Density at 10 cm resolution is in black. The
dotted vertical line indicates the density of pure ice (917 kg m−3 ); the thin inclined line denotes
dry firn density. Dashed areas mark the end of the cores. The association of each core with thethree hypothesized firn regimes is indicated at the top.

At 67◦ N, in the lower percolation zone of the western flank of the ice sheet, theformation of thick near-surface ice layers ("regime (3)" in Fig. 1) renders 32±10%of firn pore space inaccessible and forces meltwater to enter the surface discharge
system rather than percolating and being retained in the underlying firn. As a
direct consequence, ice sheet mass loss is intensified; in summer 2012 9±3% of
total runoff originated in the zone of perched ice layers (∼1680 to 1870 m a.s.l.).
Strong evidence suggests that the above described processes take place overextended areas of the lower Greenland percolation zone.

A comprehensive data base of glacier surface mass balance observations from the ablation area of the ice
sheet and the local glaciers of Greenland
H. Machguth1,2 , H.H. Thomsen1 , A. Weidick1 , J. Abermann3 , A. P. Ahlstrøm1 , M. L. Andersen1 ,D. van As1 , R.J. Braithwaite4 , C. E. Bøggild2 , J. Box1 , W. Colgan1 , R.S. Fausto1 , K. Gleie1 ,B. Hynek5 , H. Oerter6 , K. Steffen7 , M. Stober8 , R.S.W. van de Wal9
1 Centre for Arctic Technology, Technical University of Denmark, Denmark
2 Geological Survey of Denmark and Greenland GEUS, Copenhagen, Denmark
3 Asiaq, Nuuk, Greenland

4 The University of Manchester, Manchester, United Kingdom

5 Zentralanstalt für Meteorologie und Geodynamik, Vienna, Austria
6 Alfred Wegener Institute, Bremerhaven, Germany

7 Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
8 Stuttgart University of Applied Sciences, Stuttgart, Germany

9 Institute for Marine and Atmospheric Research Utrecht (IMAU), Utrecht University, the Netherlands

Glacier mass balance measurements on Greenland started nearly a century ago.
While accumulation measurements have been compiled in a number of studies, nocomprehensive overview of the data from the ablation zone of the ice sheet andfrom the local glaciers exists. These data are missing in the evaluation of modelled22Figure 1. Map of the location and temporal description of the Greenland melt area and local
glacier surface mass budget observations contained in the database.

glacier mass balance, but they also bare the potential of specifying changes inglacier melt independently from modelled data.
Here we present a comprehensive data base of glacier mass balance observations from the ablation zone of the Greenland ice sheet and the local glaciers.
The data base contains a total of >2400 mass balance observations from 36 sites(Fig. 1). For each mass balance observation X, Y and Z coordinates, starting andending dates and quality flags are provided. Sources are given for each entry andfor all metadata. The mass balance data is accompanied by a literature base.
Most data were collected from grey literature and unpublished archive documents. 50% of the data have not been published before and were thus inaccessi23

ble to the scientific community. Only 13% of the data already existed in tabulated
form including dates and coordinates.
The data cover all regions of Greenland except for the southernmost part of theeast coast. The earliest measurements date from 1938. Numerous extensive andsystematic campaigns were carried out but nearly all of them were discontinued
after a few years, only the observations along the K-Transect and at Swisscamp exceed 20 years. Once published, the mass balance data base including all sources
becomes openly accessible.

Queen Elizabeth Island glacial surface elevation change
from airborne altimetry 1995-2012
C. Mortimer, M. Sharp
Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Canada

Rapid warming and enhanced melt from glaciers and ice caps have made theQueen Elizabeth Islands (QEI), Arctic Canada, one of the largest glacier contributors to the non-steric component of global sea level rise, after the major ice sheets
in Greenland and Antarctica (Gardner et al., 2013). Between 2005 and 2009 meansummer surface temperatures in the QEI were 0.8◦ C to 2.2◦ C warmer than thoseof the previous pentad (2000-2004) (Sharp et al., 2011) and field based mass balance measurements show 2005-2009 was the most negative pentad since records
began in the early 1960s (Koerner, 2005). In light of the observed warming andmass changes it would be expected that glacier surface elevations in the QEI will
have decreased since the year 2000.
The rate of surface elevation change (dH/dt) was computed from repeat laser
airborne altimetry data from 1995, 2000, 2006, 2005 and 2012. Between 1995
and 2012 surface lowering was observed in most regions of the QEI below 1100
m.a.s.l. Thinning was greatest at low elevations, decreasing with increasing elevation. Temporal variability in dH/dt was investigated by dividing the period 19952012 into three epochs of roughly equivalent length: 1995-2000, 2000-2006,
2006-2012. No significant difference in the magnitude of dH/dt or the relationship between dH/dt with elevation was observed between the first two epochswith the exception of Muller Ice Cap where dH/dt was on average 0.2 m yr−1 lessnegative above 700 m.a.s.l. during the second epoch (2000-2006) compared to
the first (1995-2000). In contrast to the first two epochs where thickening wasobserved at higher elevations, during the most recent epoch dH/dt was negativeat all elevations in all glaciated regions for which data was available. Between
2006 and 2012 dH/dt was on average five times more negative compared to thefirst two epochs.
Observed changes in surface elevation change were interpreted in the context
of summer land surface temperatures and summer minimum surface albedos derived from MODIS satellite data. We find that since 2000 (first available MODIS
data), the QEI has experienced an increase in the duration and intensity of thesummer melt season and a decrease in the minimum summer albedo. Surface
lowering is usually assumed to indicate a reduction in glacier mass, but higher
rates of firn compaction in a warmer climate can also result in surface lowering.
24Firn and ice cores from the Devon and Penny ice caps reveal an increase in firndensity since 1955 (Bezeau et al., 2013; Zdanowicz et al., 2012). These fieldmeasurements are consistent with our analysis of the MODIS data where warmer
land surface temperatures would be expected to generate more melt, leading toboth increased runoff and compaction of the firn. Melt and an increase in snow
metamorphism would also be expected to result in lower surface albedos, further
enhancing melt.
Snow, firn and ice have different reflectance properties allowing the use of surface albedo, derived from satellite imagery, to identify regions corresponding toeach. To evaluate height changes occurring in the firn zone we use MODIS whitesky albedo data to identify regions that are most likely firn and those that are
most likely glacier ice. During the last epoch thinning was observed in both firn
and glacier ice covered areas and was accompanied by a decrease in the averageminimum summer surface albedo and an increase in melt intensity. Qualitatively
this suggests that some of the observed thinning in the firn zone may be the result of firn compaction. We hypothesize that a portion of the observed thinning in
the firn zone during the most recent epoch (2006-2012) is the result of firn compaction and therefore does not equate to a loss in glacier mass. Our hypothesis iscorroborated by field measurements on the Devon Ice Cap which found a 13-80%
increase in firn density above 900 m.a.s.l. between 2004 and 2012 (Bezeau et al.,2013), however, information about changes in ice flow are required in order toquantify the proportion of elevation change that is due to changes in dynamics
versus the component that is the result of changes in surface mass balance.
References
Bezeau, P., M. Sharp, D. Burgess, G. Gascon, 2013. Subscribed Content Firn profile changes in
response to extreme 21st-century melting at Devon Ice Cap, Nunavut, Canada . J. Glaciol.,59(217), 981–991.
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 Broeke, F. Paul,2013. SA reconciled estimate of glacier contributions to sea level rise: 2003-2009. Science, 17,6134, 852-857.
Koerner, R.M., 2005. Subscribed Content Mass balance of glaciers in the Queen Elizabeth Islands,
Nunavut, Canada. Ann. Glaciol., 42, 417-423.
Sharp, M., D.O. Burgess, J.G. Cogley, M. Ecclestone, C. Labine, G.J. Wolken 2011. Extreme melt on
Canada’s Arctic ice caps in the 21st century. Geophys. Res. Lett., 38(L11501).
Zdanowicz, C., A. Smetny-Sowa, D. Fisher, N. Schaffer, L. Copland, J. Eley, F. Dupont, 2012. Summer
melt rates on Penny Ice Cap, Baffin Island: Past and recent trends and implications for regional
climate. J. Geophys. Res., 117(F02006).

Dissipative meltwater production in glaciersJ. Oerlemans
Institute for Marine and Atmospheric Research Utrecht (IMAU), University of Utrecht, Utrecht, theNetherlands

Glaciers are dissipative systems through which mass (snow, ice, water) travels
downwards to leave the system at the glacier front. This process involves theconversion of potential energy, delivered by the atmosphere during precipitation
25

events, into kinetic energy and finally dissipation. From the theory of ice mechanics it is known that the dissipation is given by the convolution of the stress andstrain rate tensors. To do such a calculation for a real glacier is a tedious exercise
for which a detailed and precise numerical model is needed. However, to obtaina feeling for characteristic numbers it is useful to consider a glacier system as anentity, which makes it much easier to estimate the total disspitation.
By estimating the dissipation from the loss of potential energy there is no needto make a distinction between solid and liquid precipitation. In the end all themass leaves the glacier at the glacier front, and the loss of energy is entirely
determined by the altitude difference between the location of mass deposition
and the glacier front.
When a glacier is (almost) temperate, disspative heating will involve melting ofice. To illustrate the concept, schematic calculations are presented for a numberof glaciers with different geometric characteristics. Typical dissipative melt rates,
expressed as water-layer depth averaged over the glacier, range from a few cm
per year for relatively dry Arctic glaciers to half a meter per year for Franz-Josef
Glacier, one of the most active glaciers in the world (in terms of mass turnover).
In a next step, meltwater production resulting from enhanced ice motion during
a glacier surge is calculated. The total generation of meltwater during a surge
is typically half a meter. For Variegated Glacier a value of 70 cm is found, for
Kongsvegen 20 cm. These values refer to water layer depth averaged over theentire glacier. The melt rate depends on the duration of the surge. It is generally
an order of magnitude larger than the water production by ’normal’ dissipation.
On the other hand, the additional basal melt rate during a surge is comparable inmagnitude to the water input from meltwater and precipitation.

Calving of tidewater glacier driven by melting at thewaterline
M. Pȩtlicki1 , M. Ciepły2 , J.A. Jania2
1 Institute of Geophysics, Polish Academy of Sciences, Warsaw, Poland.
2 Department of Earth Sciences, University of Silesia, Sosnowiec, Poland

In this contribution we present the study of the development of thermo-erosional
notch at the waterline and its influence on calving of Hansbreen, a medium size
grounded tidewater glacier in southern Svalbard. The study is based on the resultsof repeated terrestrial laser scans (TLS), analysis of time-lapse camera images
acquired year-round and oceanographic surveys of the sea water properties close
to the ice front. Measured depths of the undercut reach values of 4 m and varylargely in time. The calving activity of Hansbreen was signicantly lower in 2011
than in 2012 due to the persistent presence of the ice pack in Hornsund fjord.
Calving on Hansbreen is controlled by a local imbalance of forces at the front
due to thermo-erosional undercutting at the sea waterline. Calving activity istherefore sensitive to changes in sea water temperature and wave height. It may
be expected that calving rates will rise with increased advection of warm oceanic
water to the Arctic.

26

Snow cover, ice loss, and rock debris quantification in
an arctic glacier basin through terrestrial laser scanning surveys
A. Prokop1 , F. Tolle2 , É. Bernard2 , J.-M. Friedt3 , M. Griselin2
1 University of Natural Resources and Life Sciences, Vienna, Austria and Snow Scan GmbH, Vienna,

Austria
2 ThéMA, université de Franche-Comté, Besançon, France
3 FEMTO-ST, université Franche Comté, Besançon, France

For 3 consecutive years, terrestrial laser scanning surveys have been conductedin the glacier basin of Austre Lovénbreen (Svalbard, 79◦ N). Each year, high density
point clouds were acquired on the glacier surface and on the surrounding slopes.
Two yearly scanning sessions were required in order to spatialize and quantify
snow cover. The first session was done late April at the expected annual snow
maximum. The second session was done in August near the end of the melting
season and before the first potential significant snow falls.
On the glacier itself, laser scans were produced on the glacier snout, in the area
close to the equilibrium line, and in the upper reaches of the glacier. Manual snow
drilling measurements and glacier mass balance data were subsequently used tovalidate snow cover results.
In the steep slopes surrounding the glacier, scans were acquired on slopes atvarious altitudes and orientations in order to get a representative view of different
snow cover settings. Particular attention was granted to snowdrift and avalanche
processes, and their consequences on remaining packed snow stored in perennial
snow accumulation at the bottom of slopes.
A good knowledge of the dynamics of the snow cover is of particular interestin a glacier undergoing a clear retreat. Snow is slowing the melting of the ice forpart of the season, and snow is also providing what will constitute future glacier
ice in the upper reaches of the basin.
Snow on slopes is also of importance as avalanches reaching on the glacier
can contribute to the overall mass balance. Snow cover, by keeping the slopes
permafrost from thawing early in the season, or by providing liquid water affecting
it later in the season, is also playing a key role in the glacier basin morphology
and its interactions with the glacier body.

Modeling the response of the Juneau Icefield to climatechangeA. Roth1 , R. Hock, B. Anderson, F. Ziemen
1 Geophysical Institute, University of Alaska Fairbanks, Fairbanks, Alaska, USA

We project the future mass changes and evolution of the Juneau Icefield, one of
the largest icefields in North America (∼4100 km2 ) using a coupled mass balance
and flow model. Surface mass balance is modeled using a spatially-distributed27

temperature-index model and ice flow is modeled using a 2-D shallow ice approximation model. Input climate data of air temperature and precipitation are dynamically downscaled by the Weather Research and Forecasting Model (WRF) fromone of the Coupled Model Intercomparison Project Phase 5 (CMIP5) simulations
by the Community Climate System Model 4 for the historical period 1971-2005
and for future projections 2006-2100 at 20 km resolution. Surface mass balance,
ice thickness, and ice velocity are simulated on a 300 m grid for each month forthe period of 1971-2010 and compared to available observations to calibrate themodel. Parameters including a snow degree-day factor, ice degree-day factor, anda precipitation correction factor are tuned to yield the best agreement between
model results and observations. Once calibrated, the model was then run for the
2010-2100 time period. Preliminary calculations indicate an ice volume decrease
and ice area decrease by 2100 that is significantly less than previous projections
made by the Parallel Ice Sheet Model PISM (63% volume loss projected, 62% area
loss projected) and projections made a global model mass balance model (79%90% volume loss projected) for the same time period. We plan to incorporate arunoff model to the current coupled mass balance and flow model to make projections for the icefield’s freshwater input to the Gulf of Alaska and to assess theeffects of the icefield’s wastage on streamflow.

The use of airborne radar reflectometry to derive nearsurface snow/firn properties on Devon Ice Cap, Canadian Arctic
A. Rutishauser1 , C. Grima2 , M. Sharp1 , D.D. Blankenship2 , D.A. Young2 , J.A. Dowdeswell3
1 Department of Earth and Atmospheric Sciences, University of Alberta, Canada
2 Institute for Geophysics, University of Texas at Austin, USA

3 Scott Polar Research Institute, University of Cambridge, England

In direct response to recent increases in summer air temperatures, ice caps in the
Canadian Arctic Archipelago now experience significant summer melt at almost allelevations (Sharp et al., 2011). In the percolation zone, this meltwater percolates
into the firn and refreezes as ice layers and lenses. Knowledge of the near-surface
firn density and stratigraphy, especially the spatial distribution of refrozen ice
layers/lenses, and their changes over time is important when computing masschange estimates from altimetry data.
Here, we present an approach for characterizing the near-surface snow/firn
properties using the surface echo from airborne radio-echo sounding (RES) measurements. The radar surface echo is a combination of a coherent (Pc) and ascattering signal component (Pn). Pc is related to the dielectric constant of theprobed surface (upper 5-10 m), whereas Pn is related to the near surface roughness. Hence, different near-surface snow/firn properties can be investigated byanalyzing the signal components Pc and Pn and their spatial variability. The Radar
Statistical Reconnaissance (RSR) methodology (Grima et al., 2013) allows the extraction of Pc and Pn from the radar signal, and also generates estimates of thesurface reflectivity and roughness. We apply the RSR method to RES data collected on Devon Ice Cap and determine Pc, Pn and the near-surface reflectivity.

28

We hypothesize that Pn is largely influenced by the presence/absence of ice layers/lenses within the firn, and use this component for a firn facies classification.
Further, we modeled the radar reflectivity for the ablation zone in response todifferent winter snowpack densities and thicknesses. From these results, we hypothesize that the RSR derived reflectivity values might be used as a measure forthe thickness of snowpack overlying glacier ice. Finally, we investigate how thesurface echo from airborne RES measurements and the RSR results might be used
to estimate the amount and thickness of refrozen ice layers/lenses within the firn.
References
Sharp, M., D.O. Burgess, J.G. Cogley, M. Ecclestone, C. Labine, G.J. Wolken 2011. Extreme melt on
Canada’s Arctic ice caps in the 21st century. Geophys. Res. Lett., 38(L11501).
Grima, C., D.M. Schroeder, D.D. Blankenship, D.A. Young, 2013. Planetary landing-zone reconnaissance using ice-penetrating radar data: Concept validation in Antarctica. Planetary and Space
Science, 103, 191-204.

Investigating the dynamics of store glacier, west Greenland using UAVs
J. Ryan1 , A. Hubbard1,2 , N. Toberg3 , P. Christoffersen3 , J. Box4 , N. Snooke5
1 Centre for Glaciology, Institute of Geography and Earth Science, Aberystwyth University, Aberys-

twyth, UK
2 Department of Geology, University of Tromsø, Tromsø, Norway
3 Scott Polar Research Institute, University of Cambridge, Cambridge, UK
4 Geological Survey of Denmark and Greenland, Copenhagen, Denmark
5 Department of Computer Science, Aberystwyth University, Aberystwyth, UK

Unmanned Aerial Vehicles (UAVs) offer exciting opportunities for acquiring highresolution data that bridge the gap between satellite imagery and ground-based
measurements. We present results from a two month field campaign during which
the terminus of Store Glacier, Greenland was surveyed repeatedly using a fixedwing UAV. Around 90,000 overlapping aerial images were captured which allowed
the production of high-resolution (<50 cm) orthophotos and digital elevation models using stereophotogrammetry. These products provide us with a unique opportunity to investigate glaciological processes at a fine spatial and temporal scale.
Feature tracking of the images are used to extract daily surface velocity fields
and strain rates. These results are combined with meteorological and satellite
data to explore the dynamics of the ice mélange and glacier before, during andafter the ice mélange breakup. The distribution of water-filled crevasses andchanges in the position and size of the meltwater plume emerging from the calving front are also assessed. These results enable the investigation into the impact
of water-filled crevasses and meltwater plumes on calving rates through the deepening of crevasses and submarine melting, respectively. We conclude that theresults and techniques used in this study demonstrate the applicability of repeat
UAV surveys to assess the short-term dynamics of tidewater outlet glaciers.

29Firn line delineation using Envisat SAR imagery from2005-2010 over Penny Ice Cap, Baffin Island, Nunavut.
N. Schaffer1 , L. Copland1 , C. Zdanowicz2 .
1 Department of Geography, University of Ottawa, Ottawa, Canada.
2 Department of Earth Sciences, Uppsala Universitet, Uppsala, Sweden.

Increased mass loss associated with rising temperatures has been observed overthe southern Canadian Arctic from geodetic measurements, particularly since2005. To assess the impact of this warming on glacier facies, the location of thefirn line on Penny Ice Cap (∼66◦ N) was mapped with Envisat SAR imagery fromMay 2005 - October 2010. Data are validated against in-situ ground-penetratingradar (GPR) transects and compared to ELA positions determined from mass balance stake measurements. The firn line observed on a GPR transect recorded in
May 2011 on the southwestern edge of the ice cap matches well with the firn line
position identified from differences in backscatter in Envisat imagery from thesame mass balance year. Applying this backscatter relationship to other years,
the firn line here remains relatively constant in location through time, possibly
due to a local peak in snow accumulation. In contrast, on the western side of theice cap the firn line has migrated up-glacier across a gently sloping region, moving 540 m upglacier between 2005-2008 and 550 m between 2009-2010. Thisaligns with increased mass loss in this region since 2005. At both locations, thestake measurements indicate that the ELA is located >15 km upglacier from theEnvisat-derived firn line. This displacement of the ELA relative to the firn line suggests that Penny Ice Cap is considerably out of balance with current climate, withold firn at depth being exposed in what is now the ablation zone. This is consistent
with warming of ∼10◦ C recorded at a depth of 10 m in the firn region since themid-1990s (Zdanowicz et al., 2012).
References
Zdanowicz, C., A. Smetny-Sowa, D. Fisher, N. Schaffer, L. Copland, J. Eley, F. Dupont, 2012. Summer
melt rates on Penny Ice Cap, Baffin Island: Past and recent trends and implications for regional
climate. J. Geophys. Res., 117(F02006).

A multivariate approach of the factors impacting a small
arctic glacierS. Schiavone1 , F. Tolle1 , É Bernard1 , J.-M. Friedt2 , M. Griselin1 , D. Joly1
1 ThéMA, université de Franche-Comté, Besançon, France
2 FEMTO-ST, université Franche Comté, Besançon, France

Arctic glaciers are good indicators of the ongoing climate change as their dynamics are strongly linked to it. This study is focused on the Austre Lovén glacier, on
the Brøgger peninsula in Spitsbergen (Svalbard, 79◦ N). The aim is to understandhow contrasted climate and snow conditions over the course of a year can lead tomultiple consequences, sometimes unexpected, on mass balance. In 2014, a negative budget was expected, but data analysis has shown the first positive mass30

balance in 7 years. The objective here is to (i) identify and qualify the combinationof factors affecting an arctic glacier mass balance. Three primary indicators seemto display the greatest influence: summer temperatures, liquid precipitations andwinter snow accumulation. A specific focus would also be to (ii) understand theseasonal chronology and to rank parameters that have the greatest influence on
glacial dynamics.
The Austre Lovén glacier (4,5km2 ) has been systematically instrumented andmonitored since 2007. Mass balance is measured yearly at the end of September
with an evenly-spaced 36 stakes network. At the end of April, before the startof the melting season, snow accumulation is also measured through drillings. Air
temperatures have been recorded continuously since 2007 with 20 sensors on theglacier. The last parameter we are mainly interested in for this study is liquid precipitation data. It could not be continuously recorded in situ because of technicalreasons. Hence it was reconstructed with data from the closest meteorologicalstation, in Ny Ålesund, about 6km from the site.
These parameters were then used as explanatory variables to identify theirinfluence on the Austre Lovén glacier. Data being recorded punctually was subjected to spatial generalization at the scale of the glacier. Factors conditioning
accumulation area are not necessarily analogous to the ones having a great influence in the ablation area. Observed data need to be prepared in order to provide more explicit indicators as input for the statistical analysis. For example,
a degree-days indicator allows to considerate only positive temperatures whichhave the greatest influence on the glacier. All of the original and derived factors
are then constituting the basis of all subsequent multivariate analysis.

Revisiting "The Mass Balance of Circum-Arctic Glaciersand Recent Climate Change"
M. Sharp
Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Canada.
With acknowledgements to G. Wolken, A. Arendt, S. O’Neil, M. Pelto, D. Burgess, G. Cogley, R.
Koerner, J. Kohler, and L. Andreassen.

One of the first activities of the IASC Working group on Arctic Glaciology (WAG)(now the Network on Arctic Glaciology, NAG) was to produce a review of in situ
mass balance measurements on glaciers from across the Arctic for the period
1946 to 1994. This work was published in Quaternary Research in 1997 with
Julian Dowdeswell as lead author and 10 co-authors (D97) (Dowdeswell et al.,1997). A further 20 years of mass balance measurements have accrued since thattime and the number of sites being monitored on a regular basis has increased.
It is therefore time to update the 1997 analysis, which reported predominantly
negative mass balances across the Arctic but a lack of any uniform mass balance
trend - although Alaskan glacier mass balances were reported to be becoming
more negative while those in maritime Scandinavia and Iceland were becoming
more positive due to increasing precipitation.
Since 1994, surface mass balance has been measured on 28 Arctic glaciers,
compared with 18 in D97. These are located in Alaska (3), Arctic Canada (4),31

Iceland (9), Svalbard (4) and northern Scandinavia (8) - though not all have beenmeasured every year (the annual sample size ranges from 12- 27). In total, 524
balance years of measurements (out of a possible 588) were made between 1994
and 2014. Consistent with D97, mean regional mass balances for the "Low Arctic"(Alaska, Iceland and northern Scandinavia) were more negative and had higher
standard deviations (-599 to -875 ± 738 to 869 kg m−2 a−1 ) than those for the"High Arctic" (Arctic Canada and Svalbard; -344 to -347 ± 389 to 393 kg m−2 a−1 ).
Only 86 (16%) of the measured annual balances were positive. 53 of these werefrom Low Arctic regions (15.1% of measured balance years) and 33 from the High
Arctic (21%). Mean annual mass balances for individual glaciers differed fromzero by between 0.1 and 2.1 standard deviations of the mean (average of 1.04
standard deviations from zero). For 18/28 glaciers, the mean differed from zeroby more than 1 standard deviation. Cumulative mass balances for the 14 complete series (1994-2013) ranged from -19,683 kg m−2 (Gulkana Glacier, Alaska)
to +2789 kg m−2 (Engabreen, Norway - the only measured glacier with a positive
cumulative mass balance).
D97 reported trends of increasingly positive annual surface mass balance for
glaciers in Iceland, Norway and Sweden prior to 1994. These trends were reversed
starting around 1993-1995, since when cumulative mass balances in these regions have become increasingly negative. Plots of regional cumulative mass balance versus time show recent accelerations in rates of mass loss from glaciers in
Alaska (starting ca.1988), Arctic Canada (starting ca.1986 with a further acceleration after 2004), and for the Arctic as a whole (starting after 1993). If we compare
the regional cumulative mass balances for the twenty-year periods 1974-1993
and 1994-2013 the differences range from -511 kg m−2 in Svalbard to - 16,570
kg m−2 in northern Scandinavia. This calculation cannot be made for Iceland due
to lack of data from the earlier epoch, but it is clear that the increase in the 20
year cumulative mass loss from individual glaciers in the Low Arctic was around
4.8 times greater than it was from glaciers in the High Arctic. The significance of
this difference is, however, reduced by the fact that the glaciated area in the High
Arctic is more than double that in the Low Arctic.
References
Dowdeswell, J.A., J-O. Hagen, H. Björnsson, A.F. Glazovsky, W.D. Harrison, P. Holmlund, J. Jania, R.M.
Koerner, B. Lefauconnier, C.S.L. Ommaney, R.H. Thomas, 1997. The Mass Balance of CircumArctic Glaciers and Recent Climate Change. Quaternary Research, 48, 1-14.

The geodetic campaign 2014 for studies in mass balance, ice dynamics and validation of satellite data in
the Swiss Camp area, West Greenland
M. Stober1 , H. Rott2 , M. Hönes1 , G. Grom1 , D. Floricioiu3
1 Hochschule für Technik Stuttgart, Stuttgart University of Applied Sciences, Germany
2 ENVEO IT and Institute of Meteorology and Geophysics, University of Innsbruck, Austria
3 Remote Sensing Technology Institute, DLR, Oberpfaffenhofen, Germany

Introduction
The long-term studies in the Swiss Camp area were continued by the most re32

Figure 1. Cumulative geodetic and surface
mass balance at Swiss Camp 1991-2014.

Figure 2. Ice flow velocities at Swiss Camp
1991-2014.

cent campaign in 2014. Since 1991 until 2014 the author now has performed 12
geodetic campaigns. In average every second year we had measured a deformation network consisting of 4 stakes forming a triangle with a central stake. There
are two research areas: 1) Swiss-Camp in an altitude of 1170 m and 2) ST2 inan altitude of 1000 m. We measured geodetic elevation changes, surface massbalance at stakes, ice flow velocities and deformation of the ice surface. Comparisons with elevation and elevation change data from CryoSat-2 and TanDEM-X
were applied for validation of the satellite data.
Results
The long-term project is able to deduce the mass balance in respect to the climatechange. At Swiss-Camp (SWC) the accumulated geodetic mass balance (GMB)
and the specific surface mass balance (SMB) at stakes are shown in Figure 1. The
negative geodetic mass balance is increasing. Starting with -0.2 m/a in the period1991 - 2002, we get now in the period 2011-2014 an elevation change rate of-1.46 m/a and the geodetic mass balance -1.31 m w.e./a. In comparison, for thesurface mass balance from the stakes we get -1.21 m w.e./a. The difference canbe explained by the long-term dynamic thinning due to the accelerated ice flow
velocity (Fig. 2).
It is well known that in summer time the ice is flowing faster (Zwally et al., 2002;
Stober et al., 2013). In Figure 3 the mean ice flow velocities between campaigns(1 up to 3 years) are shown compared to those of a summer day, calculated by
Precise Point Positioning (PPP). In most years the summer speed was significantly
higher, but on August 5th, 2014, the ice flew slower than in average 2011-2014.
At ST2 the summer flow velocity in August 2014 was equal to the average speed

Figure 3. Summer ice flow velocities at Swiss Camp, derived by Precise Point Positioning (PPP).

33

Figure 4. Cumulative geodetic and surface
mass balance at ST2 2004-2014.

Figure 5. Ice flow velocities at ST2 2004 2014.

2011-2014.
At the research area ST2 which is situated in a lower altitude and closer to theice margin we have observations since 2004 until now 2014. Here we find partly
opposite results. The negative geodetic mass balance (Fig. 4) is continuously increasing from -0.35 m w.e./a (2004-2005) up to -1.47 m w.e./a (2011-2014) andthe surface mass balance from -1.18 m w.e./a up to -1.55 m w.e./a respectively. In
opposite to Swiss-Camp the ice flow velocity (Fig. 5) is here slower and has decelerated, probably due to the bedrock topography. Bedrock and ice thickness data
(Bamber et al., 2013; DTU, 2013) show at ST2 the ice flowing against a ridge,
while at Swiss Camp it flows into a trough.
Deformation and strain rates are calculated by an affine transformation of the
stake networks between the successive campaigns 2011 and 2014. Due to theover-determined system (redundancy 2) we calculate the parameters by a leastsquares adjustment which gives also the standard deviations of the unknowns. At
Swiss Camp we get the principal strain rates e1 = 2985 +- 533 ppm/a (azimuth= 195 gon) and e2 = -3760 +- 533 ppm/a (azimuth= 95 gon). The areal distortionis given by the sum e1+e2 = -775 ppm/a and indicates a shrinking area. Withapplication of the continuity condition e1+e2+e3=0 we get the vertical component e3 = +775 ppm/a. Neglecting the variation of a depth dependent velocity
variation and together with the local ice thickness (H=1180 m) we get a positive
vertical velocity of e3*H = +0.91 m/a, but no mass gain, because of the assumed
continuity condition and incompressibility of the ice. The same calculation at ST2
in the years 2011-2014 leads to the horizontal strain rates e1 =+5911 ppm/a(azimuth 171 gon) and e2 = -3550 ppm/a in perpendicular direction and so in vertical e3 = -2361 ppm/a. The resulting distortion in area yields to an enlargementof +2361 ppm/a and with the ice thickness H = 600 m the vertical velocity resultsin the dynamical elevation change -1.42 m/a. The continuity condition postulates
elevation change in spite of constant mass. The decreasing horizontal ice flow
velocity at ST2 indicates a diminished in-flow into the ST2 area compared to thelong-term equilibrium state. The geodetic mass balance (Figure 1, 4) is the resultof all geometrically measurable effects including all dynamical and meteorologicalparts; SMB contains only the meteorological part.
The high quality of our digital terrain models are used for comparison withelevations and elevation change data from CryoSat-2 and TanDEM-X. The CryoSat2 data were provided by Helm et al. (2014) with elevation change results between
1/2011 and 1/2014. Our comparison shows on average differences in temporalelevation change of 0.25 m/a (SWC) and 0.57 m/a (ST2). Few days after our
34

Figure 6. Height discrepancies (after best fit) between TanDEM-X (August 16th, 2014) and GPS
ground measurements (August 5th, 2014). The marginal regions are not representative due to bad
constitution of the DEM here.

ground measurements at Swiss Camp the TanDEM-X satellite had passed the same
area. The DLR (Rott and Floriciociu, 2015) provided us with one (uncalibrated)digital elevation model (DEM) with a very good horizontal resolution of 5 m. Aftercorrection with a systematic offset of 3.14 m the best fit all over the area (1847
points) achieves on average the standard deviation 0.025 m and for one point1.07 m. The residuals of these 1847 points amount mostly between +1m and -1m(Fig. 6).
References
Bamber J. L. , J. A. Griggs, R. T. W. L. Hurkmans, J. A. Dowdeswell, S. P. Gogineni, I. Howat, J.
Mouginot, J. Paden, S. Palmer, E. Rignot, and D. Steinhage, 2013. A new bed elevation dataset
for Greenland. The Cryosphere, 7, 499–510.
DTU, 2013. Microwave and Remote Sensing, DTU Space, The Technical University of Denmark. Personal communication.
Helm, V., A. Humber, H. Miller, 2014. Elevation and elevation change of Greenland and Antarctica
derived from CryoSat-2. The Cryosphere, 8, 1–21.
Rott and Floriciociu. Personal communication.
Stober M., J. Hepperle and R. Wössner, 2011. Precise Point Positioning (PPP) and its application to
studies in ice dynamics in West Greenland. In: IASC Workshop and Network on Arctic Glaciology
annual meeting, Extended Abstracts, 59-61, Ed: C.H. Tijm-Reijmer. ISBN: 978-90-393-6003-3.
Zwally, H.J., W. Abdalati, T. Herring, K. Larson, J. Saba and K. Steffen, 2002. Surface melt-induced
acceleration of Greenland ice-sheet flow. Science, 297(5579), 218–222.

Comparing the Geodetic and Glaciological mass budgets of White Glacier, Axel Heiberg Island, NU
L. Thomson1 , L. Copland1 , M. Zemp2
1 Laboratory for Cryospheric Research, Geography, University of Ottawa, Canada
2 World Glacier Monitoring Service, Zurich, Switzerland

White Glacier is a 14 km polythermal glacier extending from 50-1800 m a.s.l on
western Axel Heiberg Island, NU. It hosts the longest mass balance record for35

an alpine glacier in the Canadian Arctic, now exceeding 50 years. In this study,
we conduct a reanalysis of the mass balance record and update estimates of thesystematic and random errors associated with generating geodetic and glaciological mass budgets. We compare the geodetically derived mass change of White
Glacier from 1960 to 2014, with the cumulative results of glaciological mass balance observations.
The geodetic mass budget is derived from the volumetric difference between
a 1:10,000 map of White Glacier created in 1960, and a new DEM created fromaerial stereo-photographs collected in July 2014. Through careful co-registration,
we minimized the uncertainty and systematic error to arrive at a geodetic balance of -9.05 ± 1.69 m w.e. over the 54 year time period. Historically, the massbalance of White Glacier has been calculated using the hypsometry of the glacierat its 1960 extent with a localized update to the glacier geometry below 400 m
a.s.l. in 2003, resulting in a cumulative reference balance of -11.35 m w.e.. To
account for changing glacier geometry through time, we homogenize the glaciological mass balance observations through conversion to conventional balances
using estimates of the changing glacier hypsometry. Over 54 years we find a resulting cumulative conventional balance of -11.26 ± 2.73 m w.e.. We discuss thediscrepancy between the geodetic and cumulative glaciological mass budgets,
which in part reflects the generic differences between the two methods.

Dynamics and Changes in Extent of Bylot Island andBarnes Ice Caps, Nunavut, Canada
W. Van Wychen1,2 , F. Delaney1 , L. Copland1 , D.O. Burgess2 , L. Gray1
1 Department of Geography, University of Ottawa, Ottawa, Canada
2 Natural Resources Canada, Geological Survey of Canada, Ottawa, Canada

Recent studies indicate a sharp increase in glacier mass wastage from the Canadian Arctic due to higher summer air temperatures (Gardner et al., 2012; Sharp
et al., 2011). Previous comparisons of aerial photography and Landsat imagery
indicate that between 1959/60 and 2000 the Bylot Island and Barnes Ice Caps
decreased in areal extent by ∼5% and ∼2%, respectively (Sharp et al., 2014).
However, little is known about the detailed patterns within this period, or how
these ice caps have changed since the start of the 21st century. To address theseissues, we digitized the extents of these ice caps using Landsat 8 imagery acquired in the summers of 2013/2014, and used historical Landsat data to digitize
the extent of both ice masses in each decade from 1980-2000. The Bylot Island
Ice Cap total ice area decreased by ∼3.8% between 1975 and 2013/14, with most
ice loss concentrated on small, low elevation glaciers. The Barnes Ice Cap total ice area decreased by ∼3.4% between 1980 and 2013/14, with most ice loss
occurring in the stagnant northwestern region of the ice mass.
To determine the complete surface velocity field of each ice cap for the firsttime, we utilized speckle tracking of ALOS PALSAR (2007-2011) data. Generally,
surface glacier velocities of the ice masses of Baffin and Bylot Island are low,with peak velocities of ∼100 m a−1 and mean velocities of ∼30-60 m a−1 . The
measured velocity structure reveals that peak velocities tend to occur near the36equilibrium line altitude on Penny and Bylot Island Ice Caps, while the fastest
velocities on all other glaciers usually occur near the terminus due to relatively
large accumulation areas draining through narrow outlets. These glacier velocity results provide baseline data from which future changes in ice dynamics canbe detected, allow for the calculation of iceberg calving fluxes from the regions
tidewater glaciers, and can be used as inputs for glacier flow models.
References
Gardner, A.S., G. Moholdt, A. Arendt and B. Wouters, 2012. Accelerated contributions of Canada’s
Baffin and Bylot Island glaciers to sea level rise over the past half century. The Cryosphere, 6,1103–1125.
Sharp, M., D.O. Burgess, J.G. Cogley, M. Ecclestone, C. Labine, G.J. Wolken 2011. Extreme melt on
Canada’s Arctic ice caps in the 21st century. Geophys. Res. Lett., 38(L11501).
Sharp, M., D.O. Burgess, F. Cawkwell, L. Copland, J.A. Davis, E.K. Dowdeswell, J.A. Dowdeswell, A.S.
Gardner, D. Mair, L. Wang, S.N. Williamson, G.J. Wolken, F. Wyatt, 2014. Recent glacier changes
in the Canadian Arctic. [In Global Land Ice Measurements from Space: Satellite Multispectral
Imaging of Glaciers], pp 205-228. J.S. Kargel, M.P. Bishop, A. Kaab, B.H. Raup, G. Leonard Eds.
Springer-Praxis.

Cascading effects of sea ice losses on the formationand preservation of tidewater glacier tongues and ice
shelves on northern Ellesmere Island, Nunavut, Canada
A. White, L. CoplandDepartment of Geography, University of Ottawa, Ottawa, Canada

According to the study of Koenig et al. (1952), it was proposed that the ice shelvesof northern Ellesmere Island form from floating tidewater glacier ice tongues that
extend into sea ice and coalesce with other ice tongues. Observations on current ice shelves, such as the Milne and Petersen, suggest that glacier inputs may
be locally important, but to date no assessment has been made of the controls
on ice tongue formation and preservation on northern Ellesmere Island. Reports
from early explorers (e.g., Peary, 1906) and observations of ice islands suggestthat an ice shelf filled Yelverton Bay and its southern regions, Kulutingwak Fiord
and Yelverton Inlet, until the 1940s. Field observations, aerial photographs (1950,
1959) and SPOT satellite imagery (1987) reveal that multiyear landfast sea ice(MLSI) filled Yelverton Bay after this, with eight glacier tongues (up to 4 kmlong) flowing into Yelverton Inlet and Kulutingwak Fiord. Observations of Landsat and ASTER satellite imagery reveal that partial losses occurred from mostglacier tongues between 2003-2004 and again between 2005-2007. An open water event in summer 2008 led to the complete loss of glacier tongues (up to 4 kmlong) at the northern end of Yelverton Inlet, while an open water event in 2011
caused the complete loss of the remaining glacier tongues at the southern endof the inlet, including the entire glacier tongue (∼15 km) at the front of Yelverton
Glacier. The timing of these losses was associated with the loss of >690 km2 of
MLSI from Yelverton Bay in August 2005, followed by removal of multi-year landfast sea ice (MLSI) from Yelverton Inlet and Kulutingwak Fiord in summers 2008
and 2010. Based on these losses, it is clear that perennial sea ice plays a crucial

37

role in stabilizing glacier tongues. Once this perennial sea ice is lost the floating portion of ice tongues are no longer preserved, thus disabling their ability tothicken amongst sea ice and potentially facilitate ice shelf formation.
References
Koenig et al., 1952. Arctic ice islands. Arctic, 5, 66-103.

Capabilities of the Sentinel-1 SAR mission for operational monitoring of ice sheets
J. Wuite1 , T. Nagler1 , M. Hetzenecker1 , H. Rott1,2
1 ENVEO IT GmbH, Innsbruck, Austria
2 Institute of Meteorology and Geophysics, University of Innsbruck, Austria

Numerous studies indicate large and rapid changes on the Greenland Ice Sheet(GIS) in the last decade in response to changing boundary conditions, including
record surface melt and dynamical changes of marine terminating glaciers. As aresult the contribution of the GIS to global sea level rise has increased significantly.
With the launch of the first satellite of the European Sentinel-1 SAR satellite seriesin April 2014, glaciologists are provided with a new tool to remotely measure iceflow velocity and monitor calving fronts and grounding line deformation. These
are key parameters to determine calving fluxes and the dynamic response of theice masses to climate forcing and to changes in mass balance.
In full deployment the Sentinel-1 mission is a constellation of two identical operational SAR satellites offering unique capabilities for regular and comprehensive
repeat observations of the global ice masses. The Sentinel-1 satellites carry a Cband synthetic aperture radar instrument providing high resolution SAR images
in different acquisition modes, including the Interferometric Wide-Swath mode
(IWS), which will be the main acquisition mode over land areas. Data is acquired
across 250 km swaths at a spatial resolution of about 5 m x 20 m. We use 12-day
repeat pass SLC images of Sentinel-1 A acquired in autumn 2014 to obtain ice
flow velocity fields of several large Greenland outlet glaciers. We apply an iterative offset tracking approach, permitting to acquire the full range of velocities ina single swath while keeping the matching window at a minimum. The results arecompared with ice flow velocity fields derived from repeat pass data of other sensors, including ALOS PALSAR and the TerraSAR-X mission. Combined these data
sets allow for a unique assessment of ice-velocity changes in recent years andhighlights the potential of Sentinel-1 for ice sheet monitoring.

38