Working Report 2010-07 Present Conditions in Greenland and the Kangerlussuaq Area Anne Birgitte Nielsen January 2010 POSIVA OY Olkiluoto FI-27160 EURAJOKI, FINLAND Tel +358-2-8372 31 Fax +358-2-8372 3709 Working Report 2010-07 Present Conditions in Greenland and the Kangerlussuaq Area Anne Birgitte Nielsen Geological Survey of Denmark and Greenland January 2010 Working Reports contain information on work in progress or pending completion. The conclusions and viewpoints presented in the report are those of author(s) and do not necessarily coincide with those of Posiva. ABSTRACT Greenland is the world’s largest island, with an area of 2.2 million square kilometres, 80 % of which is covered by the ice sheet. The climate is Arctic, but as Greenland stretches 2600 km from north to south, there is a huge variability in climate, with temperature decreasing from south to north. Due to the influence of oceanic currents, the west coast is slightly warmer than the east coast. Precipitation also decreases strongly from the south to the north, and also with distance from the coast. Kangerlussuaq is located in the dry, continental area of central west Greenland. The bedrock of Greenland is dominated by Precambrian gneisses, with sedimentary rocks occurring in some areas of East and North Greenland, and smaller areas of basalts. All of Greenland has been glaciated several times and has thus been eroded and shaped by the ice, as it still is at the ice margin. Soils are generally thin, and especially in the gneiss regions rather poor in plant nutrients. Permafrost occurs throughout the ice free areas of Greenland. It is continuous in the north, discontinuous along parts of the central east and west coast and occurs as isolated patches in the south. Kangerlussuaq is in the southernmost part of the continuous permafrost zone. The spatial variability in climate is also reflected in the vegetation zones, which range from Arctic dessert in the far north, through dwarf shrub zones with increasing plant height and density towards the south, to the arctic shrub zone in the continental parts of West Greenland and subarctic Birch forest in South Greenland. The terrestrial food chains in Greenland are generally short and with few species. Cyclic variation in population sizes has been observed in some mammal species, including lemming and caribou. Many species of mammals and birds are associated with the coastal environment, which is therefore also and important resource area for the human population. Fishery is the most economically important industry in Greenland, and meat from hunting plays an important role in local consumption. Human settlement has occurred since 2500 BC, when the first palaeoeskimo people arrived from Canada. However, occupation has been interrupted by periods of extinction associated with climate changes. Today the population is 57 000, which is ca. 0.2 people per km2 of ice free area. There is no arable agriculture, but sheep farming occurs in south Greenland, and impacts the vegetation locally. However, the main human impact on ecosystems is not land use, but direct impact on populations through fishing and hunting. Keywords: Greenland, natural conditions, climate, bedrock, vegetation, human activity, settlement history Grönlannin ja Kangerlussuagin luonnonolosuhteet ja ihmistoiminta TIIVISTELMÄ Grönlanti on maailman suurin saari ja sen pinta-ala on noin 2.2 miljoonaa neliö- kilometriä, josta noin 80 prosenttia on jään peitossa. Grönlannin ilmasto on arktinen, mutta koska saari on pohjois-etelä -suunnassa 2600 kilometriä pitkä, on ilmasto-oloissa suurta vaihtelua. Merivirtojen vaikutuksesta saaren länsirannikko on hieman itäran- nikkoa lauhkeampi. Sadanta pienenee selvästi etelästä pohjoiseen ja toisaalta siirryt- täessä rannikolta sisämaahan. Kangerlussuag sijaitsee kuivalla, mantereisella alueella läntisessä Grönlannissa. Grönlannin kallioperää hallitsevat prekambriset gneissit. Sedimenttikiveä esiintyy pai- koitellen saaren itä- ja pohjoisosissa. Pienillä alueilla esiintyy myös basaltteja. Koko Grönlanti on jäätiköitynyt useita kertoja ja maaston muodot ovat näin ollen jään muokkaamia. Maaperä on tyypillisesti ohutta ja erityisesti kallioperältään gneissisillä alueilla vähäravinteista. Ikiroutaa esiintyy jäättömillä alueilla. Ikirouta-alue on yhtenäi- nen saaren pohjoisosissa, epäyhtenäinen osissa itä- ja länsirannikon keskiosia ja esiintyy erillisinä laikkuina etelässä. Kangerlussuag sijaitsee yhtenäisen ikirouta-alueen etelä- osassa. Ilmaston alueellinen vaihtelu heijastuu myös kasvillisuusvyöhykkeisiin, jotka vaihtelevat pohjoisen arktisesta aavikosta varvikko vyöhykkeiden kautta enenevämmän kasvikorkeuden ja -tiheyden luonnehtimaan etelään. Etelä-Grönlannissa kasvaa koivuja. Maaekosysteemissä ravintoketjut ovat yleisesti ottaen lyhyitä ja vähälajisia. Popu- laatiokokojen syklisyyttä on todettu joillain nisäkäslajeilla kuten sopuleilla ja karibuilla. Monet nisäkäs- ja lintulajit elävät rannikolla, joka näin on myös merkittävä alue ihmistoiminnan kannalta. Kalastus on Grönlannin täkein elinkeino ja metsästys on merkittävä tekijä paikallisessa kulutuksessa. Ihmisasutusta on ollut saarella 2500-luvulta e.a.a. lähtien, jolloin ensimmäiset inuiitit saapuivat alueelle nykyisen Kanadan suunnalta. Yhtämittaista asutusta kuitenkin katkaisevat jäätiköitymiskaudet. Tänä päivänä väestöä on noin 57 000 ja väentiheys noin 0.2 as/neliökilometri jäättömällä alueella. Viljelytoimintaa Grönlannissa ei ole, mutta lampaankasvatusta on saaren eteläosissa, mikä vaikuttaa paikallisesti myös kasvillisuuteen. Pääasiallinen ihmis- toiminnan vaikutus ympäristöön ei kuitenkaan tule maakäytön vaan kalastuksen ja metsästyksen kautta. Avainsanat: Grönlanti, luonnonolot, kallioperä, kasvillisuus, ilmasto, ihmistoiminta, asutushistoria PREFACE This report is produced as part of the Greenland Analogue Project (GAP), carried out as a collaboration project with the Canadian Nuclear Waste Managing Organization (NWMO), Posiva Oy and Swedish Nuclear Fuel and Waste Management Co (SKB) as collaborating and financing partners. The overall aim of the project is to improve the current understanding of how ice sheets, during future cold periods, affect the groundwater flow and hydrochemistry around a deep geological repository in crystalline bedrock. 1 TABLE OF CONTENTS ABSTRACT TIIVISTELMÄ PREFACE 1. STUDY AREA ...................................................................................................... 3 1.1 Greenland ..................................................................................................... 3 1.2 Kangerlussuaq .............................................................................................. 4 2. CLIMATE AND METEOROLOGY ........................................................................ 7 2.1 General characteristics .................................................................................. 7 2.2 Spatial variation across Greenland ................................................................ 8 2.3 The Kangerlussuaq region........................................................................... 12 2.4 Temporal variation ....................................................................................... 13 3. BEDROCK ......................................................................................................... 15 3.1 Common properties ..................................................................................... 15 3.2 Chemistry .................................................................................................... 17 3.3 Processes ................................................................................................... 17 3.3.1 Erosion ................................................................................................ 17 3.3.2 Earthquakes ........................................................................................ 18 4. SOIL .................................................................................................................. 19 4.1 Common properties ..................................................................................... 19 4.2 Soil processes in the Kangerlussuaq region ................................................ 19 4.3 Soil chemistry in the Kangerlussuaq region ................................................. 20 5. PERMAFROST .................................................................................................. 21 5.1 Common properties and definition ............................................................... 21 5.2 Spatial variation ........................................................................................... 22 5.3 Permafrost structures near Kangerlussuaq .................................................. 25 6. GLACIAL ENVIRONMENT ................................................................................ 27 6.1 The Greenland ice sheet ............................................................................. 27 6.2 Glaciation history ......................................................................................... 27 6.3 Glacial processes ........................................................................................ 28 6.4 Glacial geomorphology in west Greenland and the Kangerlussuaq region . 30 6.5 Eolian deposits ............................................................................................ 32 7. LAND ECOSYSTEMS ....................................................................................... 33 7.1 Common properties