The Norwegian Government has defined the Arctic as its most important strategic foreign policy area, and presence and knowledge are key elements. The government's updated Ocean Strategy, Blue Opportunities, addressing knowledge building and sustainable development, adds a new dimension to the policy.
The GoNorth initiative was born in 2010, following the decision by the United Nations' Shelf Commission, to support the Norwegian claim for an extended continental shelf north of Svalbard, into the Nansen Basin. A gathering of geologists at the University Centre in Svalbard, UNIS, were at the time discussing the extension of the shelf and agreed that the knowledge base was limited. Exploring the Arctic Ocean had not been given priority in Norway in recent years.
Another five years went by before the scientists got serious and formed a consortium to pursue the challenge. The Norwegian Ministry of Foreign Affairs funded a pre-project in 2016, which led to the GoNorth program getting off the ground in the winter of 2020.
International collaboration has been identified as a major success criterion for GoNorth, for scientific, logistical and financial reasons. We acknowledge that international scientists have been more active in the Arctic Ocean than Norwegian scientists in recent years.
The logistical challenges will be substantial in some of the areas we will explore. Two ships working in parallel will be essential to achieve the results we seek. Norway has a brand-new ice going research vessel with superb instrumentation in Kronprins Haakon, but it does not have an ice class comparable to Polarstern and the Swedish ice-breaker Oden.
Our scientific interests start in the subsurface
The area north of Svalbard contains several geological enigmas. Major, yet un-answered, scientific questions are:
- Why is the passive, extensional continental margin north of Svalbard unusually narrow, with main characteristics comparable with sheared margins?
- Why is the hydrothermal activity along the ultra-slow spreading Gakkel Ridge similar to much faster spreading ridges?
- What was the climatic, glacial and palaeo-oceanographic development of the Arctic during the past ~65 million years?
New and important data have been acquired in recent years, by the Norwegian Petroleum Directorate, the Alfred Wegener Institute (AWI), the German Federal Institute for Geosciences and Natural Resources (BGR) and the Russian VNIIO/GINRAS. But our understanding of the geology and sea-floor conditions in the Arctic Ocean north of Svalbard, is still limited. This is partly due to the fact that the area is logistically demanding, and because the sea-ice cover poses challenges on data acquisition.
In general, water depths on the shelf north of Svalbard are less than 400 metres, and for the most part free of ice during the summer. The continental slope to the west and north extends to below 2,500 meters depth. The Nansen Basin, which forms part of the Eurasia Basin, is a deep marine basin located between the northern margin of the Barents shelf (Svalbard and the Yermak Plateau) and the Gakkel Ridge. On average, the basin is 500 kilometers wide and 3.7 kilometers deep. We have only limited knowledge of the sedimentary sequences in the Nansen Basin.
Svalbard is a geological laboratory that can be used to obtain an understanding of the structural features that develop in the marine realm further north. Geological and geophysical data from Svalbard will help us gain an understanding of the structural framework and basin development in the Arctic Ocean. This onshore-offshore linkage will be exploited as part of our research program.
On the basis of existing seismic and gravimetric data, as well as heat flow measurements, the southern and north-western segments of the Yermak Plateau are thought to be comprised of thinned continental crust. This interpretation is supported by petrographic, geochemical and geochronological analyses of samples taken from the sea floor. The greater mass of the Yermak Plateau may thus constitute a direct structural continuation of the northern part of Svalbard. Furthermore, bathymetric features and geological structural trends on the plateau are similar to those we encounter in northern Svalbard.
The supposed oceanic segment of the Yermak Plateau is covered by a sequence of Cenozoic sediments, up to 2,000 metres in thickness. The oldest sediments may be approximately 35 million years old, but we cannot exclude the possibility that older (Paleocene) sediments may be encountered in the deepest sub-basins. The IODP sites 910 and 911 drilled through Neogene sediments in the north-western part of the Yermak Plateau, and work is ongoing to determine a higher resolution stratigraphy in these cores.
Svalbard’s northern margin, east of the Yermak Plateau, is interpreted to represent a passive continental margin. However, continental stretching is localized, and the area thus exhibits features that are more similar to a sheared margin. Preliminary geodynamic modelling indicates that the margin may have been subject to a short period of shear deformation before extension became the dominant mechanism during margin formation. Svalbard’s northern margin is thus a unique laboratory for studying the links between shear and extensional movements during continental fragmentation. The study of these processes is made easier by the fact that the margin appears to be very little influenced by magmatism which in other locations often mask tectonic processes.
The Gakkel Ridge
The Gakkel Ridge is a continuation of the Mid-Atlantic Ridge extending into the Arctic Ocean. It extends for 1,800 km through the Eurasia Basin and continues until it meets the broad continental shelf north of Siberia in the Laptev Sea, offshore of the estuary of the Lena River.
The spreading rate along the Gakkel Ridge decreases from 0.7 cm/year north of Svalbard to only 0.3 cm/year close to the Siberian continental shelf (Engen et al. 2003). This makes the Gakkel Ridge the slowest spreading ridge on Earth, which has fueled speculation that it is being formed in a different way from all other mid-ocean ridges (Edwards et al. 2001).
Given that the Gakkel Ridge and the Mid-Atlantic Ridge belong to the same ridge system, the Eurasia and North Atlantic Basins must have been formed by the same process. It is assumed that the Arctic Ocean began to open at the same time as oceanic accretion was initiated in the North Atlantic, approximately 53 million years ago (Faleide et al. 2008).
During this early opening phase, plate movements were such that Svalbard and Greenland moved laterally in relation to each other, while marine basins opened in the north and south. Subsequently, plate movement changed to assume a direction similar to today and, at the earliest approximately 17 million years ago, the Fram Strait between Svalbard and Greenland became deep enough to allow deep-water exchange between the Eurasia Basin and the North Atlantic (Jakobsson et al. 2007; Engen et al. 2008). It thus became possible for deep water masses to flow from north to south and vice versa through the Fram Strait, and this significantly changed the prevailing Atlantic climate regime and oceanic circulation patterns.
In situations where spreading rates are low, such as along the Gakkel Ridge, the mantle is relatively cold and volcanic activity is limited. This results in incomplete development of oceanic crust to the extent that the mantle gradually extends all the way up to the sea floor. In such areas, mantle peridotites are transformed into serpentine (Dick et al. 2003).
Hydrothermal systems are encountered along the spreading ridge in locations where sea water invades the basalts, sinks into the oceanic crust and at some locations into the mantle. The water is then forced back and upwards by the heat. Some of this water returns through so-called “hydrothermal vents” on the sea floor, from which super-critical fluids are discharged at temperatures of up to 400 degrees Celsius. In volumetric terms, this hydrothermal cycle, also known as the ‘oceanic crust cycle’ constitutes about one-seventh of the hydrological cycle we are familiar with on land. The fluids discharged through the vents are rich in minerals, and this flux effectively controls the concentrations of many of the elements found in seawater. Typically, massive sulphide deposits, rich in metals such as copper and zinc, will be formed in these hydrothermal fields (Pedersen et al. 2010a).
The Greenhouse-Icehouse evolution of the Arctic
The Arctic Ocean has been exposed to repeated dramatic climatic and environmental changes during the past approx. 65 million years. This includes the long-term transition from a greenhouse climate with surface water temperatures of up to 25 °C during the Paleocene-Eocene to full icehouse conditions with perennial sea-ice cover (Stein et al. 2015). Many of these environmental changes and their causes remain poorly understood and reconstructions are fragmentary, thus, requiring additional investigation and integration of terrestrial and marine records.
Recent studies show evidence for periods of sea ice as early as middle Eocene times (~47 million years ago) implying that freshwater supply played a crucial role in the hydrological cycle. Moreover, ice-rafted debris in 44 to 30 Ma old sediments in the Arctic-Atlantic gateway region indicates the presence of circum-Arctic ice sheets.
The period from the Eocene to Pliocene is characterized by a marked global cooling. However, only fragmentary knowledge is available for the transition and the history of the deep-water connection between the Arctic and Atlantic oceans. More extensive glaciations in the Atlantic-Arctic gateway region did not prevail before the early/middle Miocene, with stepwise intensification since the onset of glaciations around 3.6 Ma ago (Jakobsson et al. 2007). Reconstructions suggest that the Arctic Ocean went from an isolated, oxygen poor ‘lake stage’, to a transitional ‘estuarine sea’ phase with variable ventilation, and finally to the fully ventilated ‘global ocean’ phase near 17.5 Ma. This inferred formation of the Atlantic – Arctic gateway must have had a substantial effect on high latitude circulation and water mass exchange. However, the exact timing is still uncertain due to coring gaps. Up to date, clear evidence for a fully established deep-water exchange between Arctic and Atlantic exists since about 6.0 Ma.
Major cooling took place at the Pliocene - Pleistocene boundary, when Earth’s orbitally driven factors led to repeated fluctuations between glacial and interglacial cycles. The extent of ice sheets in the Arctic during glacial periods remains unknown (Moran et al. 2006). The first reconstructions ranged from 1 km thick ice caps to perennial sea ice with icebergs. Recent studies found evidence of grounded ice shelves on bathymetric highs in the central Arctic Ocean, suggesting the existence of a coherent, up to 1 km thick, ice shelf in central Arctic Ocean around 140 ka (MIS 6). The first extension of ice sheet to the shelf break off NW Svalbard occurred at ~2.7 Ma. The sediment transport occurred predominantly through ice streams that eroded deep cross-shelf troughs and deposited sediments in till deltas at the outer shelf and upper slope. The chronology of the Pleistocene glaciations remains poorly constrained.
Understanding the advances and retreats of the Svalbard-Barents-Kara Sea Ice Sheet (SBKSIS) during the last glaciation is highly relevant beyond its regional scale. It contributes to the understanding of global sea-level and climate changes and it can be used as an analogue to better understand current processes occurring at the margins and within the Greenland and Antarctic Ice Sheets, respectively.
The basal conditions beneath the ice sheet varied largely between areas of cold-based and relatively inactive ice, and warm-based, fast-flowing ice draining multiple ice domes through fjords and cross-shelf troughs. Fast ice flow resulted presumably in relatively thin ice masses on Svalbard and the local appearance of nunataks, but also the existence of thin, cold-based ice fields between the ice streams.
The deglaciation of the northwestern Barents Sea and Svalbard took mainly place after 20.5 ka BP. It was interrupted by multiple halts and/or re-advances and terminated in most of the inner fjords around 11.2 ka BP (Ingolfsson and Landvik 2013). Despite numerous works addressing glacial history of the SBKSIS, many of the results are conceptual and fragmentary so more firm data from marine and terrestrial records are needed for a more comprehensive understanding of past ice-sheet and glacier dynamics. This includes also the sea-level history on northern Svalbard margin which is, thus far, based on old and incomplete data sets.
GoNorth will require the use of a variety of vessels – from traditional research vessels without ice class certification, to ice-going vessels, icebreakers and drilling vessels. The northernmost part of the program, which will be investigating areas covered with fast ice, will require the use of icebreakers, and thus joint international research collaboration.
Technology, biology and geopolitics
As GoNorth developed, the scope of the program was broadened to include new technology, as well as research related to the water column and the sea surface. The main tasks in development and testing of new technology are related to ship operations in Arctic areas, underwater operations, communication and navigation, environment, geophysical surveying methods and data management. The available infrastructure includes ships, remotely operated vehicles, autonomous underwater vehicles, unmanned surface vehicles, unmanned aerial vehicles, landers and sensors.
Physical and biological processes in the water column under the Arctic sea ice are poorly understood. The ongoing climate change in the Arctic is well documented, but there are many open questions about the role of the Arctic Ocean in the climate system. GoNorth proposes to prepare and deploy a pilot for a year-round multi-disciplinary observing system to collect oceanographic data including ocean temperature, acidification, sea level, sea ice thickness, vocalizing marine life, acoustic impact of human activities, and geophysical hazardous events (e.g. earthquakes, landslides, tsunamis). Another major oceanographic objective will be to investigate the variability and interactions between the inflow of warm water north of Svalbard, the Transpolar Gyre and the Beaufort Gyre.
The complex interactions between the biosphere, hydrosphere and cryosphere are central, yet poorly understood, features of the Arctic Ocean. A perturbation in one or more may propagate and amplify through complex interactions, resulting in disproportionally large changes and/or regime shifts. Disproportionally fast warming of the Arctic and loss of sea ice are well-known examples of such amplifications that will eventually result in a seasonally open, highly illuminated, and freshened Arctic Ocean. GoNorth proposes research aiming at a better understanding of how physical, biological and biochemical drivers regulated by the presence of sea ice influence the ecological processes in the water column below.
Finally, we have added a geopolitical dimension to GoNorth, looking into how scientific knowledge may translate into political power, from historical and contemporary perspectives, and how the science-policy interface works in global governance.