Databank

Databank

Posiva publishes Working Reports and Posiva Reports. From the year 2006 nearly all the reports have been published on our webpage and they can be found in the databank. In the databank you can also find our Annual Reviews and some other publications as well. You can also find print-quality pictures and useful links in the databank.

Recent publications


Workreport 2016-37

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Name:

The Greenland Analogue Project: Data and Processes

Writer:

Harper, J., Brown, J., Hubbard, A., Doyle, S., Fitzpatrick, A., Ruskeeniemi, T., Engström, J., Claesson Liljedahl, L., Kontula, A., Liimatainen, J., Pere, T., Hobbs, M., Hirschorn, S., Kennell, L., Jones, G., Drake, H., Follin, S., Frape, S., Henkemans, E., Graly, J., Harrington, J., Humphrey, N., Hansson, K., Jansson, P., Lindbäck, K., Pettersson, R., Kinnbom, P., Klint Knud, E., van As, D, Tullborg, E.-L.

Language:

English

Page count:

416

Summary:

This report presents the methods, collected datasets, and the interpretations completed for the Greenland Analogue Project (GAP), a collaborative research project conducted between 2008 and 2013 by the national nuclear waste management organisations in Sweden (SKB), Finland (Posiva) and Canada (NWMO). The primary aims of the GAP were to enhance scientific understanding of glacial processes and their influence on both surface and subsurface environments relevant to deep geological repository (DGR) performance in crystalline shield rock settings. Based on its size, relative accessibility, and crystalline shield bedrock, the Greenland Ice Sheet (GrIS) was selected by the GAP as a natural analogue for glaciation processes expected to reoccur in Fennoscandia and Canada over DGR safety-relevant timeframes.

The GAP study area is located east of Kangerlussuaq village on the west coast of Greenland and covers approximately 12 000 km2, of which approximately 70% is occupied by the GrIS. To advance understanding of glacial hydrogeological processes, GAP research activities included both extensive field work and modelling studies of the GrIS, focused into three main subprojects: SPA) surface-based ice sheet studies; SPB) ice drilling and direct studies of basal conditions; and SPC) geosphere studies. The main objectives and activities of these subproject areas are provided below:

SPA) Surface-based ice sheet studies aimed to improve the current understanding of ice sheet hydrology and its relationship to subglacial hydrology and groundwater dynamics. This work was based primarily on indirect observations from the ice sheet surface of the basal hydrological system, to obtain information on the parts of the ice sheet which contribute water for ground­water infiltration. Project activities included quantification of ice sheet surface-water production, as well as an evaluation of how water is routed from the ice surface to the interface between the ice and the underlying bedrock. Methods employed include: remote sensing, automatic weather station network, GPS measurements of ice motion, ground-penetrating radar and seismics.

SPB) Ice drilling and direct studies of basal conditions also aimed to improve understanding of ice sheet hydrology and groundwater formation based on direct observations of the basal hydrological system, paired with numerical ice sheet modelling. Specific processes were investigated, including: 1) thermal conditions within and at the base of the ice sheet; 2) generation of meltwater at the ice/bedrock interface; and 3) hydrologic conditions at the base of the ice sheet. Activities included ice drilling of multiple holes at three locations on the ice sheet, at distances up to thirty kilometers from the ice sheet terminus, to assess drainage, water flow, basal conditions and water pressures at the interface between the ice and bedrock.

SPC) Geosphere investigations focused on groundwater flow dynamics and the chemical and isotopic composition of water at depths of 500 metres or greater below ground surface, including evidence on the depth of permafrost, redox conditions and the infiltration of glacial meltwater into the bedrock. Deep and inclined bedrock boreholes were drilled through the permafrost in the vicinity of the ice sheet margin. The boreholes were hydraulically tested and instrumented to allow hydrogeologic and hydrogeochemical monitoring. The nature of ground conditions under a proglacial lake was also investigated, to assess if areas of unfrozen ground within the permafrost (taliks) may act as a potential pathway for exchange of deep groundwater and surface water. A wide range of methods were applied by SPC to study the above including: geological, geophysical and surface water investigations, as well as bedrock borehole investigations.

Keywords:

Greenland Analogue Project, GAP, Ice sheet, Permafrost, Talik, Hydrology, Glacial hydrology, Geochemistry, Hydrogeology, Natural analogue, Greenland, Nuclear waste repository, Basal drainage system, Kangerlussuaq, Russell glacier, Leverett, Pingo, Isunnguata Sermia.

File(s):

The Greenland Analogue Project: Data and Processes (pdf) (64.4 MB)


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