The ice, the science and the icefjord

^{Many expeditions explored the Inland Ice in the 19th century. Their equipment was primitive, and travel on the ice was difficult and dangerous.}

The first descriptions of the Inland Ice date from the early Middle Ages. ‘Kongens Spejl’ (the King’s mirror), a Norwegian document written about 1260, provides a vivid first-hand description of the widespread extent of Greenland’s ice sheet:

"But as you asked whether the land is free from ice or not, or if it is covered with ice like the sea, then you should know that there is a small part of the land which is free from ice, but the rest is covered by it, and people do not know whether the land is large or small, because all fell areas and all valleys are hidden by the ice, so it is not possible to find an opening". It continues "People have often tried to go to different places on the land on the fells that are highest, to look about and try to find any part of the land that was free from ice and habitable, but nowhere has it been possible to discover such areas apart from those that are already inhabited, which stretch only for short areas along the coast" 

The initial colonisation of Greenland in 1721, and the establishment of Danish settlements (Ilulissat / Jakobshavn was founded in 1741), resulted in many descriptions of the country, the nature and the Inuit people.

Missionaries and traders who travelled along Greenland’s west coast wrote about the area around Ilulissat and the Inland Ice. Observations from the start of the 18th century indicate that the icefjord Kangia was then occasionally ice-free, whereas the margin of the glacier advanced in the 18th century and the start of the 19th century.

In 1770, the missionary David Cranz was one of the first to try to understand the origins of the Inland Ice and the icebergs, and he compared his observations with European and American glaciers. This provided the foundation for more detailed surveys of the Greenland ice sheet during the following century, when it was realised that glaciers could also yield information about earlier changes between warm and cool periods, a sort of ‘climatoscope’.

^{Traditional winter house from the Thule culture modified by a glass window.}

One person dominated the early years of true glacier research in Greenland for decades: Hinrich Rink. Rink was originally educated in chemistry and physics, but he carried out geological and glaciological studies in West Greenland between 1848 and 1852 during travels along the coast from Upernavik in the north to Qaqortoq / Julianehåb in the south.

^{Hinrich Rink (1819-1893)}

^{was a pioneer in studies of the Inland Ice, and the first to realise its enormous size.}

Hinrich Rink’s objective was to make a map of the country based on his own and earlier surveys, and supplemented by map sketches made by local hunters. He concentrated his efforts around the central part of West Greenland, an area that was then largely unknown, and he succeeded in surveying large parts of the fjords and their glaciers. Rink spent the winter of 1850/51 in Ilulissat and sailed to the margin of the Inland Ice at Paakitsoq, north of the town, in October 1850. He travelled by sledge to the southern part of Sermeq Kujalleq in April 1851, and here he determined the position of the front of the glacier. Rink’s surveys were the first in a series of observations of changes of the ice margin that have now lasted more than 150 years. Meteorological observations at Ilulissat were begun in 1873, and together with measurements of the movements of Sermeq Kujalleq from 1875, provide unique documentation of glacier frontal variations in arctic areas.

^{Map illustrating Rink’s 1862 theory of the drainage of the interior of Greenland by rivers. As the map shows, East Greenland was then not well known, and the depiction of the area north of Ilulissat in West Greenland is also imprecise. Click on the map to enlarge it.}

^{Rink’s 1857 map showing the extent of the Inland Ice, and the five large glaciers (ice streams) from the Inland Ice that drain into Disko Bugt and Uummannaq Fjord. Less important glaciers in southern Greenland are also shown. Click on the map to enlarge it.}

Through his work, Hinrich Rink became the first scientist to realise the vast extent and special form of ‘the ice plain’ covering the entire interior of Greenland, and he called this ice cover Indlandsisen, (‘Inland Ice’) after a suggestion by the Danish scientist Japetus Steenstrup. The Inland Ice was completely different from the local glaciers of northern Europe, well known from many descriptions. At about the same time a new idea was developing in Europe - that ice had once covered large parts of northern Europe in the past. Rink’s sensational news that there was an enormous ice sheet in Greenland was therefore received with particular interest in scientific circles, because it could substantiate the argument that northern Europe had been covered by ice during one or more ice ages. Rink’s descriptions also provided the impetus for glaciological expeditions to Greenland and the Ilulissat area in the following decades.

Hinrich Rink also tried to understand the mechanism behind the production of calf ice. His main theory was that the ice streams flowing from Greenland’s interior are fed by the accumulation of snow. The snow, in the form of ice, is then transported out to the coast by the ice streams - in the same way that rain over large land areas is carried to the sea by large rivers.

Rink estimated the production of calf ice on the basis of the size of the glaciers and the quantity of ice in the fjords, and he recognised five icestreams of ‘the first order’ - Jakobshavn, Tossukatek, Den større Kariak, Den større Kangerdlursoak and Upernavik. He thus realised that there was large calf ice production in five fjords, although he did not discover the unique status of Sermeq Kujalleq as the main outlet of the Inland Ice. That was first realised in the second half of the 19th century. However, Rink recognised the extraordinary size of the Inland Ice, which is indicated by his calculation of the catchment area of about 50,000 square kilometres or more that he estimated was necessary to feed each of the five glaciers.

^{The margin of the Inland Ice at Paakitsoq north of Kangia, drawn in 1850 by Hinrich Rink, one of the pioneers of glaciology. The ice margin was then advancing, and reached a maximum about 1880. Since then a gradual retreat has taken place, as is seen from the photographs from 1961 and 1987. Click on the image to enlarge it.}

Interest in Greenland’s glaciology grew in the second half of the 19th century, with an increasing number of researchers visiting Kangia and Sermeq Kujalleq; nearly all described the glacier front and its surroundings. Among the early visitors were some of the leading scientists and explorers of the time, including Erich von Drygalski, Robert E. Peary, Adolf Erik Nordenskiöld and Alfred Wegener.

During the Second World War map-making on the basis of aerial photographs was developed to a high standard, so that even remote areas such as Greenland could be mapped in detail from aerial photographs. At the same time, all-terrain vehicles were developed, which eased access to, and transport on, the inner crevasse-free areas of the Inland Ice.

The modern era started with the activities of Expéditions Polaires Francaises in the years from 1948 to 1953. The expedition’s work was focused along an East - West profile from coast to coast over central Greenland, with the purpose of measuring a profile of the bottom and surface of the Inland Ice and determining the mass balance along the route. The west end of the profile was 70 km north of Ilullisat, on the south side of Eqip Sermia glacier, and this area was the subject of detailed mapping. However, there was little direct contribution to knowledge of the Ilullissat region.

^{Researchers at work during Expéditions Polaires Francaises. (Source: The book: Indlandsisen by Børge Fristrup. Photo: Børge Fristrup)}

Expédition Glaciologique Internationale au Groenlande in 1957-1960 was a collaboration between Austria, Denmark, France, Germany and Switzerland. Using aerial photographs, the expedition determined the rate of movement of all the outlet glaciers draining into Disko Bugt and Uummannaq Fjord. At the same time the production of calf ice was assessed, and the studies confirmed Sermeq Kujalleq’s unique role with regard to the production of calf ice.

After 1960, an important project was undertaken to determine the thickness of the Inland Ice and map the altitude of the ice surface and the topography of the landscape under the ice using airborne radar. More than 60,000 kilometres of profiles were collected over six seasons between 1968 and l976 - the first overall survey of the landscape under the Inland Ice. The survey was a breakthrough in the understanding of the dynamics and geomorphology of glaciers and ice sheets, and in climate research.

However, there was still a lack of detailed knowledge about the continuation of Kangia and the channel occupied by Sermeq Kujalleq beneath the margin of the Inland Ice. Some of this information has since been collected during investigations of the potential for using melt water for hydropower production. For this purpose a helicopter-borne radar technology was developed by the Technical University of Denmark, and modified by the Geological Survey of Denmark and Greenland. The most recent surveys of the thickness of the ice sheet around Sermeq Kujalleq were published in 2001.

Modern studies of the marginal areas of the Inland Ice are, to a large degree, based on data from satellites. Satellite monitoring of frontal changes has replaced aerial photography to some extent as it makes it possible to carry out repeated observations within a short time frame. The record of Sermeq Kujalleq’s development since 1932, established from aerial photographs, has been one of steady retreat until the 1950s. Then followed a period of relative stability until 2002, when satellite monitoring has documented a rapid retreat.

^{Sermeq Kujalleq gradually retreated between 1850 and 1992. The glacier front was more or less stable between 1950 and 2002, with seasonal fluctuations, retreat in summer and advance in winter. The 1962 and 1988 positions shown are respectively winter and spring locations of the front. The 1985 and 1992 positions show the location of the front in respectively summer and early autumn. The 1992 determination, from satellite data, also depicts the ice margin to the north and south of Sermeq Kujalleq. Click on the image to enlarge it.}

During the second half of the 20th century increasing interest was shown by glaciologists in the phenomenon of glacier surging, during which glaciers make short term advances at relatively high velocities. This phenomenon has been described for local glaciers at different places around the world. Surges have velocities comparable to the high velocities of the so-called ice streams of Antarctica and Greenland, the major drainage outlets of the ice sheets for which the high velocities are permanently maintained due to the large catchment areas.

The interest in understanding surging glaciers is related to the development of the idea that the ice sheets of the ice age may have collapsed suddenly and catastrophically. Similar considerations are relevant today with respect to the possible response of the present ice sheets to global warming as a result of the increased greenhouse effect caused by mankind. Interest in the dynamics of glaciers has therefore increased. Sermeq Kujalleq is an obvious choice for studies, partly because the region is covered by a long series of climate observations from the weather station at Ilulissat, but also because historical and scientific observations extend back for 150 years. In addition, due to studies relating to hydropower, a continuous series of temperature, precipitation and radiation measurements were made at the margin of the Inland Ice in the 1980s, to determine the quantity of melt water produced from the ablation zone.

^{Estimated maximum (blue) and minimum (turquoise) calf ice product ion from glaciers along the west coast of Greenland. The production of calf ice from Sermeq Kujalleq is in a class of its own. Click on the image to enlarge it.}

Information about the most recent changes in extent and movement of glaciers is based on surveys from satellites, which can also determine the topography of the ice and the surface velocity over large areas. The dramatic retreat of the floating segment of Sermeq Kujalleq in 2002 will undoubtedly lead to more intensive studies in the near future.