Geological Survey of Denmark and Greenland Bulletin 4, 2003, pp 85-88 85 Jakobshavn Isbræ (also known as Sermeq Kujalleq or Ilulissat Isbræ) is situated at about 69°10′N and 50°00′W in West Greenland. This major outlet from the Inland Ice has an extremely high rate of movement (nearly 1 m/hour) and thus a high production of icebergs, which via the icefjord float westwards through Disko Bugt to Davis Strait (Fig. 1). Estimates of the iceberg production are in the range of 35 ± 10 km3 ice per year, more than 10% of the entire calf-ice pro- duction of the Inland Ice (e.g. Bauer l968; Bindschadler 1984). The icefjord into which Sermeq Kujalleq calves is Kangia, best known in glaciological literature as Jakobshavn Isfjord. Spectacular changes of the glacier were observed dur- ing 2002 and 2003 at the same time as it was nominated for inclusion in the UNESCO World Heritage List under the name ‘Ilulissat Icefjord’. Nomination of ‘Ilulissat Icefjord’ and Sermeq Kujalleq The Eskimo ruins and archaeological sites in the region around the modern Greenland township of Ilulissat include representatives of all the cultural phases since the first Eskimo settlement of Greenland. The association with Greenland’s most productive glacier makes the ‘Ilulissat Icefjord’ area a strong candidate for inclusion in the UNESCO World Heritage List. In December 2000 the Government of Greenland decided to nominate ‘Ilulissat Icefjord’, and the Geological Survey of Denmark and Greenland (GEUS) was given the task of preparing the nomination document (Fig. 1; Mikkelsen & Ingerslev 2003). A decision as to whether ‘Ilulissat Icefjord’ will be awarded World Heritage List Status Jakobshavn Isbræ,West Greenland: the 2002–2003 collapse and nomination for the UNESCO World Heritage List Anker Weidick, Naja Mikkelsen, Christoph Mayer and Steffen Podlech Fig. 1. Extent of the nominated area of ‘Ilulissat Icefjord’ (red boundary lines). The ablation area and front of the glacier Sermeq Kujalleq are included, together with the entire icefjord area. Modified from Mikkelsen & Ingerslev (2003). Geological Survey of Denmark and Greenland Bulletin 4, 85–88 (2004) © GEUS, 2004 will be made at the annual meeting of UNESCO in June 2004. The nomination document includes comprehensive doc- umentation on observations and investigations of Sermeq Kujalleq. This major glacier, or ‘ice stream’, is situated in a subglacial trough that in its outer parts reaches depths of 1500 m below sea level (Iken et al. 1993; Clarke & Echel- meyer 1996), and it can be traced inland for about 100 km (Echelmeyer et al. 1991). General descriptions of the outer part of the glacier stress the quasistable conditions of the glac- ier front throughout the second half of the 20th century (Stove et al. 1983; Echelmeyer et al. 1991; Sohn et al. l997a, b). However, during an inspection visit to the nominated area in August 2003 radical changes in the situation of the glacier front were found to have occurred compared to the descrip- tion set out in the nomination document (Fig. 2). Prehistoric variations of Sermeq Kujalleq At the beginning of postglacial time (c. 9500 B.P.) the front of Sermeq Kujalleq was situated at the mouth of the fjord, about 50 km west of the front position shown in Fig. 1, rest- ing on a bank near Ilulissat at depths of 200–300 m below present sea level (Weidick 1994). Subsequently, the ice mar- gin retreated some 65–70 km, and at the end of the climatic optimum c. 5000 years ago the glacier front was located about 20 km east of the ice margin position of 1964 (Weidick et al. 1990, fig. 4). The following neoglacial readvance culminated during the Little Ice Age (A.D. 1500–1900), with the maximum posi- tion of the glacier front in 1851 (Fig. 3; cf. Bauer 1968). Since the postglacial climatic optimum the ice margin is pre- sumed to have advanced in pulses, such as it has been docu- mented for the ice margin 40 km north of Sermeq Kujalleq where the response of the ice-sheet margin has been calcu- lated for the last 1400 years (Reeh 1983). There may have been two periods of advance: at A.D. 700–800 and during the Little Ice Age (A.D. 1500–1900). Historical records of Sermeq Kujalleq Historical records of the glacier fluctuations of Sermeq Kujalleq have been collected and described by Larsen & Meldgaard (1958) and Georgi (1960). The numerous obser- vations since the beginning of the 1700s and up to 1851 sug- gest a gradual advance during this period. Subsequent to 1851 observations and descriptions are more frequent and more detailed. The first mapping of the frontal position was by Rink in 1851 (Rink 1857), the first determination of the fast movement of the glacier front was made in 1875 (Helland 1876), and seasonal fluctuations of the glacier front position were recorded by investigations in 1879–80 (Hammer 1883). Regular meteorological observa- tions were begun in the town of Ilulissat in 1873. The quasistable period of Sermeq Kujalleq 1950–2002 Recessional positions of Sermeq Kujalleq are summarised in Fig. 3. The recent part of the curve is based on aerial pho- tographs (from about 1950) and since 1962 also satellite information (Sohn et al. 1997a). This well-documented 50- 86 Fig. 2. Sermeq Kujalleq on 28 May 2003; glacierfront indicated by dashed red line. Satel-lite image by ASTER (Advanced Spaceborne Thermal Emission and Reflection Radio-meter) installed in the Terra satellite, with the position of the glacier front on 7 July 2001 indicated by dashed black line. ASTER data are distributed by the Land Processes Distributed Active Archive Center (LPDAAC), located at the United States Geological Survey’s EROS Data Center: http://lpdaac.usgs.gov year period coincides with a stable position of the glacier front at a broad part of the fjord. The quasistability of the glacier front position was probably influenced by subglacial topography (Echelmeyer et al. l991; Weidick 1992). The thinning of the glacier during the recessional period c. 1850–1950 has been estimated at more than 200 m (Weidick 1992), while observations on subsequent changes in thick- ness of the glacier front are few and scattered. A lowering of the frontal surface may have occurred from the 1960s to the 1980s (Echelmeyer et al. 1991). Between 1993/94 and 1998/99 investigations of the glacier by laser altimetry showed Sermeq Kujalleq to be one of the few Greenland out- lets showing signs of slight growth (Abdalati et al. 2001). However, since 1997 a sudden transition to a rapid thinning has occurred, starting in the lower reaches of the glacier and spreading gradually inland. By 2001 almost the entire glacier up to elevations of 2000 m exhibited thinning (Thomas et al. 2003). Substantial changes of the glacier front were therefore not entirely unexpected. The break-up of the Sermeq Kujalleq front The inhabitants of Ilulissat had observed an unusual amount of detached parts of the glacier front at the mouth of the ice- fjord in 2002, and observations during the 2003 visit showed that these parts are the result of a break-up of the floating glacier front. To date more closely the time of glacier break-up and retreat of the front, studies were made of a series of Landsat images covering the years 2001 to early 2003. It was estab- lished that the last winter advance of the quasistable period took place in March 2002, and was followed by a period of continuous break-up and recession of the glacier front. By May 2003, the glacier front was situated c. 11 km east of the ‘normal’ winter position. Major parts of the floating glacier described by Echelmeyer et al. (199l) had disappeared. Two stages in this break-up are illustrated in Fig. 2 (July 2001 and May 2003). The ‘normal’ retracted summer posi- tion of the quasistable stage (July 2001) was followed by the last winter advance of c. 3.5 km to March 2002. In May 2003, a major recession of the glacier front has occurred, and the glacier segment in Tissarissoq had become isolated and had partially disintegrated. The frontal position after 7 July 2003 is currently uncer- tain, but recession seems to have continued and it is now approaching the retracted position of the climatic optimum 4000–5000 years ago. The occurrences of marine shells in the neoglacial moraines surrounding Tissarissoq demonstrate that the area was ice-free in the past, although the duration of this ice-free period is not known. A single radiocarbon dating 87 Fig. 3. Top: Approximate recessional positions of Sermeq Kujalleq. Modified from Bauer (1968). Bottom: Conceptual reces- sional curve of the Sermeq Kujalleq glacier front, based on the positions given by Bauer (1968) up to 1964. The younger parts of the curve are based on satellite information by Stove et al. (1983), Sohn et al. (1997a, b) and later Landsat and ASTER images. The width of the curve depicts range of seasonal variations in the position of the glacier front. Note the rapid break-up and retreat from 2002–2003. Bauer (1968) and Georgi (1960) give very advanced positions of the front in 1870 and 1880; both were considered uncertain by Engell (1904), and have therefore been omitted here. 88 of a walrus tusk is currently available (4290 ± 100 B.P.; Weidick 1992). Local legends record that this area was for- merly ice-free and used as a hunting locality (Hammer 1883, p. 5). If these legends record a real event, then the end of the open-water period and advance of the ice may be as recent as the Little Ice Age (A.D. 1500–1900). This can only be veri- fied by extensive dating of the marine deposits, such as that carried out to determine the duration of open water in Nioghalvfjerdsfjorden in North-East Greenland (Bennike & Weidick 2001). Acknowledgement The nomination project received financial support from the Danish Ministry of the Environment as part of the environmental support pro- gramme Dancea – Danish Co-operation for Environment in the Arctic. References Abdalati, W., Krabill, W., Frederick, E., Manizade, S., Martin, C., Sonntag, J., Swift, R., Thomas, R., Wright, W. & Yungel, J. 2001: Outlet glacier and marginal elevation changes: near-coastal thinning of the Greenland ice sheet. Journal of Geophysical Research 106(D24), 33729–33741. Bauer, A. 1968: Missions aériennes de reconnaissance au Groenland 1957–1958. Observations aériennes et terrestres, exploitation des pho- tographies aériennes, détermination des vitesses des glaciers vêlants dans Disko Bugt et Umanak Fjord. By A. Bauer, in collaboration with M. Baussart, M. Carbonnell, P. Kasser, P. Perroud and A. Renaud. Meddelelser om Grønland 173(3), 116 pp. Bennike, O. & Weidick, A. 2001: Late Quaternary history around Nioghalv- fjerdsfjorden and Jøkelbugten, North-East Greenland. Boreas 30, 205–227. Bindschadler, R.A. 1984: Jakobshavn Glacier drainage basin: a balance assessment. Journal of Geophysical Research 89, 2066–2072. Clarke, T.S. & Echelmeyer, K. 1996: Seismic-reflection evidence for a deep subglacial trough beneath Jakobshavns Isbræ, West Greenland. Journal of Glaciology 42(141), 219–232. Echelmeyer, K., Clarke, T.S. & Harrison, W.D. 1991: Surficial glaciology of Jakobshavns Isbræ, West Greenland. Part I: Surface morphology. Journal of Glaciology 37(127), 368–382. Engell, M.C. 1904: Undersøgelser og Opmaalinger ved Jakobshavns Isfjord og Orpigsuit i Sommeren 1902. Meddelelser om Grønland 26(1), 70 pp. Georgi, J. 1960: Otto Fabricius und andere über die Eisverhältnisse auf Grönland, mit einem Exkurs auf den Jakobshavner Gletscher. Polar- forschung 4 (Jahrgang 28, 1958, Heft 1–2), 79–91. Hammer, R.R.J. 1883: Undersøgelser ved Jakobshavns Isfjord og nærme- ste Omegn i Vinteren 1879–1880. Meddelelser om Grønland 4(1), 68 pp. Helland, A. 1876: Om de isfyldte Fjorde og de glaciale Dannelser i Nordgrønland. Archiv for Matematik og Naturvidenskab 1, 69 pp. Iken, A., Echelmeyer, K. & Funk, M. 1993: Mechanism of fast flow in Jakobshavn Isbræ, West Greenland. Part I: Measurements of tempera- ture and water level in deep bore holes. Journal of Glaciology 39, 15–25. Larsen, H. & Meldgaard, J. 1958: Paleo-Eskimo cultures in Disko Bugt, West Greenland. Meddelelser om Grønland 161(2), 75 pp. Mikkelsen, N. & Ingerslev, T. (eds) 2003: Nomination of the Ilulissat Icefjord for inclusion in the World Heritage List. Document prepared for UNESCO, 136 pp. Copenhagen: Geological Survey of Denmark and Greenland. Reeh, N. 1983: Ikke-stationær beregningsmodel for Indlandsisens rand- zone. Gletscher-hydrologiske Meddelelser Grønlands Geologiske Undersøgelse 83/7, 81 pp. Rink, H. 1857: Grønland, geografisk og statistisk beskrevet. Vol. 1: Det nordre Inspektorat, 420 pp.; vol. 2: Det søndre Inspektorat, 588 pp. København: Andr. Fred. Høst. Sohn, H.G., Jezek, K.C. & van der Veen, C.J. 1997a: Jakobshavn Glacier, West Greenland: 30 years of space-borne observations. Geophysical Research Letters 25, 2699–2702. Sohn, H.G., Jezek, K.C. & van der Veen, C.J. 1997b: Seasonal variations in terminus position of Jakobshavn Glacier, West Greenland. In: van der Veen, C.J. (ed.): Calving glaciers. Byrd Polar Research Center Report 15, 137–140. Stove, G.C., Green, K., Birnie, R.V., Davidson, G., Bagot, K., Palmer, M., Kearn, G., Ritchie, P.F.S. & Sugden, D.E. 1983: Monitoring iceberg pro- duction from West Greenland tidewater glaciers using Landsat data. Results of the AGRISPINE experiment for the Jakobshavn Isbræ, 32 pp. Macaulay Institute for Soil Research, Craigiebuckler, Aberdeen, Scotland and the National Remote Sensing Centre, Farnborough, Hampshire, England. Thomas, R.H., Abdalati, W., Frederick, E., Krabill, W., Manizade, S. & Steffen, K. 2003: Investigation of surface melting and dynamic thin- ning on Jakobshavn Isbræ, Greenland. Journal of Glaciology 49(165), 231–239. Weidick, A. 1992: Jakobshavn Isbræ area during the climatic optimum. Rapport Grønlands Geologiske Undersøgelse 155, 66–72. Weidick, A. 1994: Fluctuations of West Greenland calving glaciers. In: Reeh, N. (ed.): Workshop on the calving rate of West Greenland glac- iers in response to climate change, 143–168. Copenhagen, Denmark: Danish Polar Center. Weidick, A., Oerter, H., Reeh, N., Thomsen, H.H. & Thorning, L. 1990: The recession of the Inland Ice margin during the Holocene climatic optimum in the Jakobshavn Isfjord area of West Greenland. Palaeogeography, Palaeoclimatology, Palaeoecology 82, 389–399. Authors’ addresses A.W., N.M. & C.M., Geological Survey of Denmark and Greenland, Øster Voldgade 10, DK-1350 Copenhagen K, Denmark. E-mail: awe@geus.dk S.P., Department of Geophysics, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen Ø, Denmark. << /ASCII85EncodePages false /AllowTransparency false /AutoPositionEPSFiles true /AutoRotatePages /All /Binding /Left /CalGrayProfile (Dot Gain 20%) /CalRGBProfile (sRGB IEC61966-2.1) /CalCMYKProfile (U.S. Web Coated \050SWOP\051 v2) /sRGBProfile (sRGB IEC61966-2.1) /CannotEmbedFontPolicy /Warning /CompatibilityLevel 1.4 /CompressObjects /Tags /CompressPages true /ConvertImagesToIndexed true /PassThroughJPEGImages true /CreateJDFFile false /CreateJobTicket false /DefaultRenderingIntent /Default /DetectBlends true /ColorConversionStrategy /LeaveColorUnchanged /DoThumbnails false /EmbedAllFonts true /EmbedJobOptions true /DSCReportingLevel 0 /SyntheticBoldness 1.00 /EmitDSCWarnings false /EndPage -1 /ImageMemory 1048576 /LockDistillerParams false /MaxSubsetPct 100 /Optimize true /OPM 1 /ParseDSCComments true /ParseDSCCommentsForDocInfo true /PreserveCopyPage true /PreserveEPSInfo true /PreserveHalftoneInfo false /PreserveOPIComments false /PreserveOverprintSettings true /StartPage 1 /SubsetFonts true /TransferFunctionInfo /Apply /UCRandBGInfo /Preserve /UsePrologue false /ColorSettingsFile () /AlwaysEmbed [ true ] /NeverEmbed [ true ] /AntiAliasColorImages false /DownsampleColorImages true /ColorImageDownsampleType /Bicubic /ColorImageResolution 300 /ColorImageDepth -1 /ColorImageDownsampleThreshold 1.50000 /EncodeColorImages true /ColorImageFilter /DCTEncode /AutoFilterColorImages true /ColorImageAutoFilterStrategy /JPEG /ColorACSImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /ColorImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /JPEG2000ColorACSImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /JPEG2000ColorImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /AntiAliasGrayImages false /DownsampleGrayImages true /GrayImageDownsampleType /Bicubic /GrayImageResolution 300 /GrayImageDepth -1 /GrayImageDownsampleThreshold 1.50000 /EncodeGrayImages true /GrayImageFilter /DCTEncode /AutoFilterGrayImages true /GrayImageAutoFilterStrategy /JPEG /GrayACSImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /GrayImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /JPEG2000GrayACSImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /JPEG2000GrayImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /AntiAliasMonoImages false /DownsampleMonoImages true /MonoImageDownsampleType /Bicubic /MonoImageResolution 1200 /MonoImageDepth -1 /MonoImageDownsampleThreshold 1.50000 /EncodeMonoImages true /MonoImageFilter /CCITTFaxEncode /MonoImageDict << /K -1 >> /AllowPSXObjects false /PDFX1aCheck false /PDFX3Check false /PDFXCompliantPDFOnly false /PDFXNoTrimBoxError true /PDFXTrimBoxToMediaBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ] /PDFXSetBleedBoxToMediaBox true /PDFXBleedBoxToTrimBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ] /PDFXOutputIntentProfile () /PDFXOutputCondition () /PDFXRegistryName (http://www.color.org) /PDFXTrapped /Unknown /Description << /FRA /ENU (Use these settings to create PDF documents with higher image resolution for improved printing quality. 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