Introduction
The northernmost land point in the world has fascinated explorers for centuries, with the north tip of continental Greenland, Kap Morris Jesup, first visited by Robert E. Peary in 1900. The later discovery and naming of an offshore island c. 33 km east of Kap Morris Jesup was first sighted by Danish geologist Lauge Koch in 1921, who named it “Kaffeklubben Island” after the informal club composed of staff members from the former Mineralogical Museum and the former Geological Survey of Denmark. Only in 1969 did early satellite measurements confirm that the northern tip of “Kaffeklubben Island” was actually the northernmost land point in the world (Lillestrand, Roots, Niblett & Weber, Reference Lillestrand, Roots, Niblett and Weber1970). Later, following a 1991 ski expedition, Greenland explorer Peter Brandt proposed the name “Inuit Qeqertaat” (Greenlandic for “island of the people”), which is now confirmed as the official name by the Greenland Place Names Committee, and therefore the name used in the rest of this paper.
The discovery of a new islet c. 1.5 km north of Inuit Qeqertaat in 1978, later named “Oodaaq Island”, was measured in connection with the first modern geodetic survey of northernmost Greenland by the Danish Geodetic Institute and has since attracted a multitude of private and a few governmental reconnaissance expeditions to search for or confirm the existence of more than ten such northern islets, as reported in details in Bennike and Shea (Reference Bennike and Shea2019). When revisited, most of these islets, as well as the original “Oodaaq Island”, seemed to have either disappeared or moved, which caused speculations as to their formation and disputes about which island is actually the northernmost island in the world. As late as 2021, a Swiss-Danish expedition, “Leister Around North Greenland Expedition”, discovered yet another fairly large islet, reported in world media as a new northernmost island. In 2022, a new Swiss-Danish expedition visited the area, to confirm the existence of the 2021 island and to visit all previously discovered island positions in the area to confirm their existence and to elaborate their strange appearances, movement and disappearances over the years; see Figure 1 and Table 1. Apart from investigating the offshore islets, the purpose was also to carry out general inter-disciplinary research in this rarely visited part of Greenland from a base camp set up at Kap Morris Jesup during August 2022.
Figure 1. The location of Inuit Qeqertaat (Kaffeklubben Island) and the other islets reported in the area from 1978 to 2021.
Table 1. Reported islands and islets north of Greenland named according to Bennike and Shea (Reference Bennike and Shea2019). All of the locations in Table 1 were visited, but apart from Qeqertaq Avannarleq, there were no icebergs and debris at, or near, the position of any of them
Historical review – Inuit Qeqertaat and new islets 1978–2021
Robert E. Peary sighted in 1900 a small island east of Kap Morris Jesup and named it “Marie Island” after his daughter. This is likely the first recorded observation of Inuit Qeqertaat, which was then resighted by Lauge Koch and Inuiterk, Etukussuk and Nugapiinguak during the Danish Jubilee Expedition in 1921. While Peary is the source of the first written account of the island, the Independence I culture, which arrived in Peary Land around 2400 BC and settled in northernmost Greenland until c. 1900 BC, most probably knew of the island, which is clearly visible from the shoreline. Furthermore, there is also evidence that the more recent Thule Culture travelled along the Greenland north coast and passed Kap Morris Jesup on their way further east (Grønnow & Fog Jensen, Reference Grønnow and Fog Jensen2003). Lauge Koch laid the first stone in the studies of Quaternary geology in the area during his expeditions (1916–1918 and 1921) which was later followed up by the Danish Peary Land Expedition during 1947–1950 (Laursen, Reference Laursen1954). After the founding of the Geological Survey of Greenland (GGU) in 1965, geological and geomorphological studies continued (e.g. Weidick, Reference Weidick1972) and later at The Geological Survey of Denmark and Greenland after a merge with GGU in 1995. A common perception among studies of the region’s glacial landforms and historic extents of the Greenland Ice Sheet north of Greenland suggests that the moraine making up Inuit Qeqertaat may well be part of a former glacial push in a west-east direction, likely from the Kap Washington area (Funder & Larsen, Reference Funder and Larsen1982), and that the maximum extension of the Greenland Ice Sheet during the Last Glacial Maximum (LGM) is to be found further offshore than today’s coastline (Larsen et al., Reference Larsen, Kjær, Funder, Möller, vander Meer, Schomacker, Linge and Darby2010; Jakobsson et al., Reference Jakobsson, Andreassen, Bjarnadóttir, Dove, Dowdeswell and England2014).
Surveys and development in the northernmost part of Greenland commenced with Operation Groundhog in the 1950s with early helicopter visits, the establishment of Station Nord as a Danish military outpost and emergency runway for bomber aircraft, and later installations of an unmanned weather station at Kap Morris Jesup. During the first modern survey and mapping of northern Greenland in 1978, which had a side goal to position both Kap Morris Jesup and Inuit Qeqertaat, the small c. 50 × 100 m Oodaaq Island was sighted by geodetic survey assistant Uffe Petersen to the north of Inuit Qeqertaat during Doppler satellite measurements at the north tip of Inuit Qeqertaat. The “island” was subsequently visited by helicopter and positioned by triangulation. After that, Oodaaq Island was officially added to the topographic maps of Greenland and also later used as a baseline point for definition of the territorial waters north of Greenland.
Since the discovery of Oodaaq Island, the number of expeditions and with them new discoveries of northerly islets in the area has steadily grown to a state where the area has become somewhat mysterious as new islands seemed to appear and then disappeared again (Dawes & Glendal, Reference Dawes, Glendal, Martens, Jensen, Meldgaard and Meltofte2003; Shea, Reference Shea2012; Dawes & Lautrup, Reference Dawes and Lautrup2017). Groups of scientists, explorers and the Danish Military Sirius Dog Sledge Patrol have since made numerous visits to the area, often to leave again with new discoveries of little islets. It has been debated whether these new discoveries qualified as islands and/or if they were permanent features, icebergs, ice-pressed ridges or merely banks of gravel and rock created by sea ice interacting with the sea floor, hereby bulldozing material up in shallow coastal zone waters (Bennike & Shea, Reference Bennike and Shea2019). Further attention to the area was gained during the summer of 2021, when researchers from Denmark and Switzerland discovered a new northernmost potential island and gave it the unofficial name Qeqertaq Avannarleq, Greenlandic for “northerly island”, attracting much attention from world media (e.g., Reuters; CNN, BBC, Le Monde, New York Times, South China Morning Post, The Independent).
Methods
During the first weeks of August 2022, an interdisciplinary Swiss-Danish team, funded by the Swiss Leister Foundation, carried out interdisciplinary investigations in northern Peary Land, as well as along the coastal zone of the Arctic Ocean between Kap Morris Jesup and Inuit Qeqertaat. Apart from the fieldwork on the sea ice which is the main focus of this paper, research comprised of height measurement of selected mountains (summits in the Roosevelt Range), gravity measurements in order to supplement the elevation change measurements of the Greenland GNET permanent GNSS network stations and the associated isostatic rebound. Furthermore, geological reconnaissance in a variety of locations in Peary Land including the High Arctic ZN-PB Belt, measurements of CO2 and methane fluxes and other effects of current warming were also carried out along with investigations of soil microorganisms and their physiological and metabolic mechanisms under extreme conditions. The expedition also retrieved lake sedimentary records from lakes as paleoclimatic and pollution archives. The expedition was serviced by an AS350 helicopter and based at a temporary field camp at Kap Morris Jesup. Part of the fieldwork was aimed at confirming the existence of the new 2021 islet, as well as visiting the earlier reported islet positions and collecting data to understand the formation and disappearance of these islets. The investigations started with precise geodetic measurements with GNSS positioning receivers (Javad type), sea ice drilling equipment (Kovacs) and bathymetric measurements (Garmin Striker 4 echosounder), supplemented by a lead weight line in case of uncertain transducer measurements through the narrow Kovacs drill holes in the ice. Additional geodetic measurements then included the first summer sea ice freeboard measurements from helicopter-borne laser scanning (Riegl Q240i), gravimetric measurements and tide gauge recordings at Kap Morris Jesup; see Figure 2. The laser scanning was also aimed at measuring sea ice free-board and thus the ice thickness to serve as a complement to CryoSat and ICESat satellite validation flights carried out in the same area during winter conditions in early April 2022 as part of ESA Cryosat validation campaigns being carried out repeatedly in the Arctic Ocean north of Greenland since 2003 (Forsberg, Keller & Jacobsen, Reference Forsberg, Keller and Jacobsen2002).
A variety of earth observation satellites were used to support the planning of the 2022 fieldwork and to get a first overview of the offshore conditions. ENVISAT, Radarsat, Sentinel-1 and MODIS satellite imagery provided a long-term time-series overview of fast ice, mobile ice, common break-up patterns and open water areas. High-resolution satellite imagery from Pleiades and Worldview from the summer of 2021 and 2022 then provided local details on sea ice features and was used to locate drilling and measurement sites. The expedition received operational weather and ice support from the Greenland Ice Service at the Danish Meteorological Institute before and during the field campaign, and it quickly became clear that 2022 was a year of unusually little sea ice north of Greenland, with open water some 10–30 km off the shoreline by late August; see Figures 3 and 4. Sea ice terminology is used in accordance with WMO Sea Ice nomenclature (WMO, 2014)
Figure 2. Example of fieldwork setup that was used when working on and near Qeqertaq Avannarleq. (a) The Gravity Meter, Scintrex CG-6 Autograv was used for gravity measurements. Geodetic GNSS Javad receivers operating in DGNSS mode using a coastal reference receiver and GNET station (KMJP-GNSS) giving sub-meter accuracy in WGS84. (b) Kovacs ice auger with a battery-powered drill was used to drill down through the sea ice, and through the drill holes, bathymetric measurements were carried out using a Garmin GT8HW-IF transducer. This transducer features a wide band CHIRP traditional sonar (150–240 kHz) at a beam width of 24–16. Ice thickness was measured by use of the Kovacs ice thickness gauge, a device, which when lowered through a borehole and then pulled upward will bridge across the hole at the bottom of the ice to ensure accurate thickness measurements. (c) Bathymetric measurements were also manually validated using a line counter of reel (led weight line) to confirm the Garmin measurements. (d) A temporary tide gauge, Xylem-Global Water, was installed at Kap Morris Jesup for the duration of the expedition. (e) The Garmin echosounder provided depths measured through the drill holes and readily sounded in excess of 100 m. This photo is from the location of Stray Dog West and shows a depth of approximately 44 m. (f) An airborne laser scanner, Rigel LMS-Q240i, was mounted by the left-hand side window of the AS350 helicopter. The same Rigel LMS-Q240i was used during spring of 2022 to LIDAR scan the area mounted on a Twin Otter DHC6 plane.
Figure 3. Sea ice conditions charted by the Greenland Ice Service at the Danish Meteorological Institute on 24 August 2022.
Figure 4. Sea ice conditions on 24 August 2022 from the Modis satellite, showing large open water area north of Greenland (courtesy of NASA/GSFC).
Results of the 2022 islet reconnaissance measurements
Despite the open water north of Greenland in August 2022, it was still possible to land at all reported islet positions (Fig. 1) and also to carry out bathymetric profiles from land to more than 100 m water depth, close to the outer edge of the fast ice. Apart from Qeqertaq Avannarleq, where a partly debris-covered tabular iceberg was still present from the year before, there were no icebergs or debris at or near the positions of any of the former islet discoveries (Fig. 1). There were no signs of any of the former islets, just sea ice covering the area. Measurement sites were chosen as the nearest suitable landing site for the helicopter which was generally very close to the reported islets position, possibly due to mostly thick multi-year sea ice throughout the area. The area was overflown a number of times and thoroughly examined with regard to sea ice types, filmed and photographed. Numerous tabular icebergs with debris on top, both stranded and floating, were observed both in the area and adjoining waters (Fig. 6), but there were no examples of first-year ice or multi-year ice with debris on it. Distinguishing icebergs from sea ice in the area was generally straightforward. The results of the bathymetric profile measurements are shown in Figure 5, while the measured depths at all reported islet locations are shown in Table 1.
Figure 5. Profile measurements of bathymetry N and NW of Inuit Qeqertaat, from echo sounding through the drill holes in the sea ice, showing a gradual increase in water depths towards the north. The two transects of drilling were done to more than 100-m water depths, close to the outer edge of the fast ice. The new 2021 feature “Qeqertaq Avannarleq” is indicated at the 26 m indication just NW of Inuit Qeqertaat.
The necessary helicopter operations on the landfast ice were fortunately possible due to the relatively thick ice, with ice thicknesses ranging from 131 to 360 cm during August 2022, and with an average thickness from measurements being 238 cm. These numbers should not be taken as presentative of the general landfast ice thickness, due to bias related to selection of helicopter landing positions. The landfast ice zone north of Greenland is known to only rarely break up and mainly consists of multi-year sea ice (MYI, 2–4 m thick) with areas of thinner second-year sea ice (SYI) and first-year ice (FYI). Beyond the landfast ice, the ice north of Greenland flows mostly from west to east, carrying many smaller and larger icebergs with it. The MYI surface consisted during the summer of 2022 mostly of large interconnecting irregular puddles, with meltwater pools and a well-developed drainage system and somewhat thinner greenish-blue colored second-year ice showing a less pronounced drainage system and numerous small puddles. Extensive rubble fields, weathered ridges and hummocked ice were observed together with areas of shore ice ride-ups where the sea ice had been pushed ashore as a slab.
The majority of the icebergs observed during reconnaissance flights were embedded in the sea ice as small tabular icebergs, some obviously recognised as coming from glaciers with middle moraines due to their stripes of supra-glacial (moraine) deposits (Fig. 6). Dome, wedge and blocky shaped icebergs were also observed, most of them small (15–60 m), but some larger (121–200 m), and all quite similar in extent to some of the reported islets. Generally, the number of smaller icebergs were quite numerous when considering the distances to the nearest floating glacier tongues.
Figure 6. Debris-covered ice island fragments photographed in August 2022. The feature in photo A had the working title “Leister Island 2022” during the expedition and shows the distinct island-like appearance, similar to the other reported “islets” in the area. Photo: Martin Nissen.
To support the bathymetry measurements, gravity measurements with an accuracy of 0.01 mGal (10–8 g) were made at the 2021 Qeqertaq Avannarleq islet, as well as a few other islet locations. Measurements centered on the islet, and on the sea ice adjacent to the islets, showed no local anomaly associated with the assumed islets, indicating that the asserted islets cannot be real islets; such a feature should for a surrounding water depth of for example 26 m at the 2021 islet position give a local gravity anomaly around 1.8 mGal.
Discussion
The transect of drillings provides a general bathymetric overview of the coastal zone bathymetry and confirms that the assumption of a very shallow and wide coastal zone bordering Peary Lands northern shoreline around Cape Moris Jessup is incorrect, and thereby that the premise of interpreting the islets as ice-pressured marine sediments forming these small islets is also incorrect. The size of obviously stranded icebergs throughout the area also supports this conclusion, while the gravity measurement results rule out that the formerly asserted islets could be small mounds of sediment standing on the sea bottom. The transect of drillings exposed an offshore seabed rise north of the 2021 islet (Figure 5). This ridge may be interpreted as a terminal moraine ridge developed by the Greenland Ice Sheet at the Last Glacial Maximum (LGM) as suggested by Jakobsson et al. (Reference Jakobsson, Andreassen, Bjarnadóttir, Dove, Dowdeswell and England2014). The bathymetric measurements in the waters near the location of the 2021 islet and Inuit Qeqertaat generally showed water depths in the 26–34 m range. Smaller tabular icebergs can easily drift into these waters and could then get stuck on the seabed until sufficient iceberg melt lifted them again and returned them to floating icebergs, before eventually drifting around Nordøstrundingen and down along the east coast of Greenland. The very limited tidal range in the region (c. 0.25 m between high tide and low spring tide was measured at Kap Morris Jesup during the expedition) has probably been a factor in preventing the icebergs from floating again once they were stranded, and as such also the understanding of them as islets instead of sediment-covered icebergs, just remaining in the area for quite long.
Even if sea ice features, like ridges and stamukhi generated during for example storms could be so thick that they could reach and push sediments from the sea floor; it is impossible that such features would elevate sediments from depths of 24–34 m and as such reach the water surface. Sea ice interacting with the sea floor is well known from deep MYI and FYI ice keels, which in extreme cases exceed down to 20–45 m depth (Lepparanta, Reference Lepparanta2011), but none of the processes of sea ice-ocean floor interactions are known to push larger amounts of sea bottom sediments all the way to the surface from greater depths. Therefore, the obvious explanation of all the islets north of Kap Morris Jesup are stranded tabular icebergs with a cover of debris.
Common for all the previously discovered “islets” are their roundish shapes, the small size of less than 100 × 100 m, heights of 2–4 m above sea level and their sediment cover consisting of silt, sand and gravel along with rounded pebbles, cobbles and boulders (Bennike & Shea Reference Bennike and Shea2019). Characteristic of the debris-covered ice features are also typically their low freeboard, which adds to their island-like appearances, particularly when embedded in MYI conditions. The calving glaciers near Kap Morris Jesup (see example in Fig. 8) have front heights in the range of 3–10 m (as measured with ICESat-2 satellite laser) and are therefore potential sources for the stranded icebergs. A stranded tabular iceberg at 26 m depth would have a freeboard height of 2.6 m, assuming a glacier ice density of 0.92 g cm−3 and an ocean water density of 1.03 g cm−3. The height above water of some icebergs in the area is consistent with airborne lidar measurements of height of the icebergs, formerly interpreted as islets, in April 2022 (Fig. 7).
Figure 7. Airborne laser scans (LIDAR) from April 2022 over the 2021 Qeqertaq Avannarleq, marked with a triangle. The freeboard heights of the feature are consistent with a stranded iceberg. All heights given are relative to The National 2016 Greenland Geoid.
Another physical characteristic is a commonly ride-up of sea ice along and over the edges of the “islets”, which somehow erase the normally distinct border between ice types. Commonly, stranded or grounded icebergs embedded in fast ice have distinct tidal cracks surrounding the perimeter, and this is not so distinct in the area partly due to the modest tidal range.
Generally, the debris-covered icebergs, formerly being interpreted as islets, show limited signs of wave activity around the edges, suggesting a relatively short and sheltered journey in open water that is from calving to becoming stranded in the vicinity of Inuit Qeqertaat. This supports the assumption that the “islets” originate from nearby marine-terminating glaciers. The nearest marine-terminating glaciers near Kap Morris Jesup are the 2 km wide Nordgletsjer at the bottom of Sands Fjord, the Moore Glacier – and some of the wider glaciers further to the west, like the ones in Benedict Fjord near Kap Christian IV (Figs. 8 and 9). Many of these glaciers carry extensive medial moraine lines.
Figure 8. The marine-terminating glacier in Benedict Fjord. Calved tabular icebergs with supra-glacial features like mid-moraines are seen in the open water in front of the glacier. Photo: René Forsberg.
Figure 9. Marine-terminating glaciers observed to carry vast amounts of debris on the surfaces towards the northern shores of Peary Land. Insets show (1) glacier outlets in Benedict Fjord, (2) Nordgletsjer in Sands Fjord and (3) Moore Gletsjer in Bliss Bugt.
Conclusions
The observations and measurements made during the Leister Go North 2022 expedition all show, beyond any doubt, that the reported islets north of Greenland are all located in relatively deep water and can as such not be made of material being pushed up beyond sea level from a shallow sea bottom. The only reasonable explanations of the features are that they are small tabular icebergs covered with moraine material that have stranded in shallow water to remain there until melting and break-up enables them to float away. This explanation is supported by the fact that the ice underneath the moraine material on some of the larger “islets” has a freeboard elevation out of the water that matches the height above water of a stranded iceberg on the relevant water depths. Finally, the absence of any gravimetric anomaly, indicating that the features should be built by sediments also supports this conclusion. It is therefore concluded that the features previously interpreted as islets are in fact stranded icebergs. The northernmost land point in the world is therefore again, the northern tip of Inuit Qeqertaat (Kaffeklubben Island) at latitude 83°39′54″ N, 30°37′45″ W. (Fig. 10).
Figure 10. The northernmost point of land on Earth, Inuit Qeqertaat, or “Coffee Club Island”, seen from SE during the Leister 2022 expedition. The white spot helicopter can be seen at the highest point of the island to the north. Drone photo by Martin Nissen.
The recently published new national topographic map of Greenland, published by the Danish national mapping agency, reflects this finding, and the 1978 Oodaaq Island has therefore been removed from the official maps.
Acknowledgments
We thank the Leister Foundation for supporting the 2022 expedition and Henrik Lassen, Arctic Capacity, for planning the expedition logistics. Henrik Lassen also helped with the ice drilling. We thank Ole Bennike and Willy Weng, Geological Survey of Denmark and Greenland, and Kristian Keller, Casper Jepsen and Anders Færch-Jensen, Danish Agency for Climate Data for advice and processing/equipment help. Marcus H. Jepsen, a student at DTU Space, processed IceSat-2 data. Operational support with weather and ice conditions was provided by the Greenland Ice Service at the Danish Meteorological Institute.
Competing interests
The authors have no conflicts of interest to declare, and no financial interest to report. We certify that the submission is original work and is not under review at any other scientific publication.
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