Jakobshavn Isbræ, West Greenland: the 2002–2003 collapse and nomination for the UNESCO World Heritage List

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 production 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 during 2002 and 2003 at the same time as it was nominated for inclusion in the UNESCO World Heritage List under the name ‘Ilulissat Icefjord’

Million years of Greenland Ice Sheet history recorded in ocean sediments

Geological records from Tertiary and Quaternary terrestrial and oceanic sections have documented the presence of ice caps and sea ice covers both in the Southern and the Northern hemispheres since Eocene times, approximately since 45 Ma. In this paper focussing on Greenland we mainly use the occurrences of coarse ice-rafted debris (IRD) in Quaternary and Tertiary ocean sediment cores to conclude on age and origin of the glaciers/ice sheets, which once produced the icebergs transporting this material into the adjacent ocean. Deep-sea sediment cores with their records of ice-rafting from off NE Greenland, Fram Strait and to the south of Greenland suggest the more or less continuous existence of the Greenland ice sheet since 18 Ma, maybe much longer, and hence far beyond the stratigraphic extent of the Greenland ice cores. The timing of onset of glaciation on Greenland and whether it has been glaciated continuously since, are wide open questions of its long-term history. We also urgently need new scientific drilling programs in the waters around Greenland, in particular in the segment of the Arctic Ocean to the north of Greenland

Methane and possible gas hydrates in the Disko Bugt region, central West Greenland

Current climate models predict an annual temperature increase in the Arctic between 4° and 6°C by the end of the 21st century with widespread impact on the Arctic environment. Warming will lead to thawing of the widespread, permanently frozen, high-latitude peat-lands and to degradation of marine gas hydrates, both of which may increase the rate of methane release to the atmosphere. This will influence global climate as methane is a potent greenhouse gas with a large global warming potential. Marine gas hydrates are found worldwide on continental margins and frequently occur in the Arctic. Interpretation of seismic profiles has also indicated their presence in the Disko Bugt region in western Greenland

Late-Holocene Atlantic bottom-water variability in Igaliku Fjord, South Greenland, reconstructed from foraminiferal faunas

A high-resolution record of late-Holocene subsurface water-mass characteristics in outer Igaliku Fjord, South Greenland, is presented based on benthic foraminifera faunas from core PO 243–451 collected from a water depth of 304 m. Strati” cation with Atlantic water masses present in the lower part of the water-column is suggested to have prevailed during the last 3200 cal. years, except for a period referred to as the‘Mediaeval Warm Period’ (MWP). During the MWP (c. ad 885–1235) the outer part of Igaliku Fjord experienced enhanced vertical mixing and a high hydrodynamic energy level which we ascribe to increasing wind stress through this period, corresponding to the period of the Norse settlement. The transition from the MWP to the‘Little Ice Age’ (LIA) shows a two-step pattern with a short climatic amelioration around AD 1520 before maximum cooling occurred. The intensified wind stress and the overall environmental change are suggested to have contributed to the loss of the Norse settlement in Greenland. Periods with strong stratification and marked in uence of Atlantic subsurface water masses around 2.6, 1.3 ka BP and during the LIA are correlated to North Atlantic Holocene ice-rafting events reported by Bond et al. (1997)

Vulnerability of the North Water ecosystem to climate change

High Arctic ecosystems and Indigenous livelihoods are tightly linked and exposed to climate change, yet assessing their sensitivity requires a long-term perspective. Here, we assess the vulnerability of the North Water polynya, a unique seaice ecosystem that sustains the world’s northernmost Inuit communities and several keystone Arctic species. We reconstruct mid-to-late Holocene changes in sea ice, marine primary production, and little auk colony dynamics through multi-proxy analysis of marine and lake sediment cores. Our results suggest a productive ecosystem by 4400–4200 cal yrs b2k coincident with the arrival of the first humans in Greenland. Climate forcing during the late Holocene, leading to periods of polynya instability and marine productivity decline, is strikingly coeval with the human abandonment of Greenland from c. 2200–1200 cal yrs b2k. Our long-term perspective highlights the future decline of the North Water ecosystem, due to climate warming and changing sea-ice conditions, as an important climate change risk

Stable carbon and oxygen isotope ratios of planktonic and benthic foraminifera of ODP Hole 115-714B (Table 1)

Combined data on benthic foraminifers, siliceous fossils, and stable isotopes depict times of enhanced organic carbon oxidation in the sediments and high primary productivity in the southern Indian upwelling zone during the Miocene. Increased abundance of the diatom productivity index, the Thalassionema group, elevated diatom and uvigerinid abundances, and bolivinid diversity all suggest heightened primary productivity and the development of a mid-depth oxygen minimum between ~17 and 10 Ma. The abundance of bolivinids with large pores and crenulate chamber surfaces may indicate more aerated pore waters in the upper few centimeters of the partly siliceous sediments deposited during the episode of higher primary productivity and increased organic carbon flux around 10 Ma