• Ancient plant DNA, macro- and microfossil studies of the lake sediments from the High Arctic lake Tenndammen, Svalbard 

      Poliakova, Anastasia; Håkansson, Lena M.; Schomacker, Anders; Pastor, Sandra Garces; Alsos, Inger Greve (Conference object; Konferansebidrag, 2020-05)
    • Ancient sedimentary DNA shows rapid post-glacial colonisation of Iceland followed by relatively stable vegetation until the Norse settlement (Landnám) AD 870 

      Alsos, Inger Greve; Lammers, Youri; Kjellman, Sofia Elisabeth; Merkel, Marie Føreid; Bender, Emma Marie; Rouillard, Alexandra; Erlendsson, Egill; Gudmundsdottir, Esther Ruth; Benediktsson, Ívar Örn; Farnsworth, Wesley Randall; Brynjólfsson, Skafti; Gísladóttir, Guðrún; Eddudóttir, Sigrún Dögg; Schomacker, Anders (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-04-08)
      Understanding patterns of colonisation is important for explaining both the distribution of single species and anticipating how ecosystems may respond to global warming. Insular flora may be especially vulnerable because oceans represent severe dispersal barriers. Here we analyse two lake sediment cores from Iceland for ancient sedimentary DNA to infer patterns of colonisation and Holocene vegetation ...
    • Arctic and sub-Arctic lake water δ2H and δ18O along a coastal-inland transect: Implications for interpreting water isotope proxy records 

      Kjellman, Sofia Elisabeth; Thomas, Elizabeth K.; Schomacker, Anders (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-04)
      High-latitude lakes are sensitive to climate change and store information about large-scale circulation changes and catchment-integrated processes. Lakes are mainly recharged by meteoric water, meaning that some lake sediment proxies may indirectly archive the stable isotopic composition of hydrogen (δ<sup>2</sup> H) and oxygen (δ<sup>18</sup>O) of past precipitation. Yet, despite similar ...
    • A complete Holocene lake sediment ancient DNA record reveals long-standing high Arctic plant diversity hotspot in northern Svalbard 

      Voldstad, Linn H.; Alsos, Inger Greve; Farnsworth, Wesley Randall; Heintzman, Peter D.; Håkansson, Lena; Kjellman, Sofia Elisabeth; Rouillard, Alexandra; Schomacker, Anders; Eidesen, Pernille Bronken (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-09)
      Arctic hotspots, local areas of high biodiversity, are potential key sites for conservation of Arctic biodiversity. However, there is a need for improved understanding of their long-term resilience. The Arctic hotspot of Ringhorndalen has the highest registered diversity of vascular plants in the Svalbard archipelago, including several remarkable and isolated plant populations located far north of ...
    • The configuration, sensitivity and rapid retreat of the Late Weichselian Icelandic ice sheet 

      Patton, Henry; Hubbard, Alun Lloyd; Bradwell, T.; Schomacker, Anders (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-02-03)
      The fragmentary glacial-geological record across the Icelandic continental shelf has hampered reconstruction of the volume, extent and chronology of the Late Weichselian ice sheet particularly in key offshore zones. Marine geophysical data collected over the last two decades reveal that the ice sheet likely attained a continental shelf-break position in all sectors during the Last Glacial Maximum, ...
    • Dissolved Inorganic Geogenic Phosphorus Load to a Groundwater-Fed Lake: Implications of Terrestrial Phosphorus Cycling by Groundwater 

      Nisbeth, Catharina Simone; Kidmose, Jacob; Weckström, Kaarina; Reitzel, Kasper; Odgaard, Bent Vad; Bennike, Ole; Thorling, Lærke; McGowan, Suzanne; Schomacker, Anders; Kristensen, David Lajer Juul; Jessen, Søren (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-10-24)
      The general perception has long been that lake eutrophication is driven by anthropogenic sources of phosphorus (P) and that P is immobile in the subsurface and in aquifers. Combined investigation of the current water and P budgets of a 70 ha lake (Nørresø, Fyn, Denmark) in a clayey till-dominated landscape and of the lake’s Holocene trophic history demonstrates a potential significance of geogenic ...
    • A Driftwood-Based Record of Arctic Sea Ice During the Last 500 Years From Northern Svalbard Reveals Sea Ice Dynamics in the Arctic Ocean and Arctic Peripheral Seas 

      Hole, Georgia M.; Rawson, Thomas; Farnsworth, Wesley Randall; Schomacker, Anders; Ingólfsson, Ólafur; Macias-Fauria, Marc (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-15)
      We present a 500-year history of naturally felled driftwood incursion to northern Svalbard, directly reflecting regional sea ice conditions and Arctic Ocean circulation. Provenance and age determinations by dendrochronology and wood anatomy provide insights into Arctic Ocean currents and climatic conditions at a fine spatial resolution, as crossdating with reference chronologies from the ...
    • Geomorphology and surficial geology of the Femmilsjøen area, northern Spitsbergen 

      Allaart, Lis; Schomacker, Anders; Håkansson, Lena; Farnsworth, Wesley R.; Brynjólfsson, Skafti; Grumstad, Andreas; Kjellman, Sofia Elisabeth (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-03-09)
      Climate change is amplified in the Arctic, and establishing baseline data for its current character is important. Here we present a map of the geomorphology of the Femmilsjøen area, Spitsbergen, northern Svalbard. The regional physiography is characterised by a low-relief, high elevation mountain plateau, its high-relief steep slopes, and low-relief coastal lowlands. The results indicate that glaciers ...
    • Glacial history of the Åsgardfonna Ice Cap, NE Spitsbergen, since the last glaciation 

      Allaart, Lis; Schomacker, Anders; Larsen, Nicolaj K.; Nørmark, Egon; Rydningen, Tom Arne; Farnsworth, Wesley R.; Retelle, Michael J.; Brynjólfsson, Skafti; Forwick, Matthias; Kjellman, Sofia Elisabeth (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-30)
      The response of glaciers and ice caps to past climate change provides important insight into how they will react to ongoing and future global warming. In Svalbard, the Holocene glacial history has been studied for many cirque and valley glaciers. However, little is known about how the larger ice caps in Svalbard responded to Late Glacial and Holocene climate changes. Here we use lake sediment cores ...
    • Glacier response to the Little Ice Age during the Neoglacial cooling in Greenland 

      Kjær, Kurt H.; Bjørk, Anders A.; Kjeldsen, Kristian K.; Hansen, Eric S.; Andresen, Camilla S.; Siggaard-Andersen, Marie-Louise; Khan, Shfaqat Abbas; Søndergaard, Anne Sofie; Colgan, William; Schomacker, Anders; Woodroffe, Sarah; Funder, Svend; Rouillard, Alexandra; Jensen, Jens Fog; Larsen, Nicolaj K. (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-04)
      In the Northern Hemisphere, an insolation driven Early to Middle Holocene Thermal Maximum was followed by a Neoglacial cooling that culminated during the Little Ice Age (LIA). Here, we review the glacier response to this Neoglacial cooling in Greenland. Changes in the ice margins of outlet glaciers from the Greenland Ice Sheet as well as local glaciers and ice caps are synthesized Greenland-wide. ...
    • Holocene glacial history of Svalbard: Status, perspectives and challenges 

      Farnsworth, Wesley Randall; Allaart, Lis; Ingólfsson, Ólafur; Alexanderson, Helena; Forwick, Matthias; Noormets, Riko; Retelle, Michael J.; Schomacker, Anders (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-29)
      We synthesize the current understanding of glacier activity on Svalbard from the end of the Late Pleistocene (12,000 yrs. before present) to the end of the Little Ice Age (<i>c.</i> 1920 AD). Our glacier history is derived from the SVALHOLA database, the first compilation of Holocene geochronology for Svalbard and the surrounding waters, including over 1,800 radiocarbon, terrestrial cosmogenic nuclide ...
    • Holocene precipitation seasonality in northern Svalbard: Influence of sea ice and regional ocean surface conditions 

      Kjellman, Sofia Elisabeth; Schomacker, Anders; Thomas, Elizabeth K.; Håkansson, Lena; Duboscq, Sandrine; Cluett, Allison; Farnsworth, Wesley R.; Allaart, Lis; Cowling, Owen; McKay, Nicholas P.; Brynjólfsson, Skafti; Ingólfsson, Ólafur (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-13)
      Arctic precipitation is predicted to increase in the coming century, due to a combination of enhanced northward atmospheric moisture transport and local surface evaporation from ice-free seas. However, large model uncertainties, limited long-term observations, and high spatiotemporal variability limit our understanding of these mechanisms, emphasizing the need for paleoclimate records of precipitation ...
    • Icelandic permafrost dynamics since the Last Glacial Maximum – model results and geomorphological implications 

      Etzelmüller, Bernd; Patton, Henry; Schomacker, Anders; Czekirda, Justyna; Girod, Luc; Hubbard, Alun Lloyd; Lilleøren, Karianne Staalesen; Westermann, Sebastian (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-14)
      Iceland’s periglacial realm is one of the most dynamic on the planet, with active geomorphologicalprocesses and high weathering rates of young bedrock resulting in high sediment yields and ongoingmass movement. Permafrost is discontinuous in Iceland’s highlands and mountains over c. 800 m a.s.l,and sporadic in palsa mires in the central highlands. During the late Pleistocene and Holocene, ...
    • Late Quaternary glacier and sea-ice history of northern Wijdefjorden, Svalbard 

      Allaart, Lis; Müller, Juliane; Schomacker, Anders; Rydningen, Tom Arne; Håkansson, Lena; Kjellman, Sofia Elisabeth; Mollenhauer, Gesine; Forwick, Matthias (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-04-10)
      The deglaciation history and Holocene environmental evolution of northern Wijdefjorden, Svalbard, are reconstructed using sediment cores and acoustic data (multibeam swath bathymetry and sub‐bottom profiler data). Results reveal that the fjord mouth was deglaciated prior to 14.5±0.3 cal. ka BP and deglaciation occurred stepwise. Biomarker analyses show rapid variations in water temperature and sea ...
    • NordVulk 1974-2024 

      Sturkell, Erik; Schomacker, Anders (Journal article; Tidsskriftartikkel; Peer reviewed, 2024)
      Nordisk Vulkanologisk Institut, senare känt som Nordisk Vulkanologisk Center (NordVulk) på Island fyller 50 år 2024. Tyvärr sammanfaller jubileet med att NordVulk upphör i sin nuvarande form och en lång och framgångsrik era med nordisk vulkanologisk forskning på Island tar slut. Här berättar vi lite om NordVulks historia och bifogar några korta anekdoter från livet där.
    • Ocean-rafted pumice constrains postglacial relative sea-level and supports Holocene ice cap survival 

      Farnsworth, Wesley Randall; Blake Jr., Wesley; Gudmundsdottir, Esther Ruth; Ingólfsson, Ólafur; Larsen, Gudrún; Óladóttir, Bergrún Arna; Schomacker, Anders (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-24)
      Distally deposited tephra from explosive volcanic eruptions can be a powerful tool for precise dating and correlation of sedimentary archives and landforms. However, the morphostratigraphic and chronological potential of ocean-rafted pumice has been under-utilized considering its long observational history and widespread distribution on modern and palaeo-shorelines around the world. Here we analyze ...
    • Persistence of Holocene ice cap in northeast Svalbard aided by glacio-isostatic rebound 

      Farnsworth, Wesley Randall; Ingólfsson, Ólafur; Brynjólfsson, Skafti; Allaart, Lis; Kjellman, Sofia Elisabeth; Kjær, Kurt H.; Larsen, Nicolaj K.; Macias-Fauria, Marc; Siggaard-Andersen, Marie-Louise; Schomacker, Anders (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-03-29)
      The deglaciation of the Svalbard-Barents Sea Ice Sheet was driven by relative sea-level rise, the incursion of North Atlantic waters around Spitsbergen, and increasing summer insolation. However, ice retreat was inter rupted by asynchronous re-advances that occurred into high relative seas, during a period associated with warm regional waters and elevated summer temperatures. Better understanding ...
    • Postglacial relative sea level change and glacier activity in the early and late Holocene: Wahlenbergfjorden, Nordaustlandet, Svalbard 

      Schomacker, Anders; Farnsworth, Wesley Randall; Ingólfsson, Ólafur; Allaart, Lis; Håkansson, Lena; Retelle, Michael; Marie-Louise, Siggaard-Andersen; Korsgaard, Niels J.; Rouillard, Alexandra; Kjellman, Sofia Elisabeth (Journal article; Peer reviewed, 2019-05-01)
      Sediment cores from Kløverbladvatna, a threshold lake in Wahlenbergfjorden, Nordaustlandet, Svalbard were used to reconstruct Holocene glacier fluctuations. Meltwater from Etonbreen spills over a threshold to the lake, only when the glacier is significantly larger than at present. Lithological logging, loss-on-ignition, ITRAX scanning and radiocarbon dating of the cores show that Kløverbladvatna ...
    • Submarginal drumlin formation and late Holocene history of Fláajökull, southeast Iceland 

      Jónsson, Sverrir A.; Benediktsson, Ívar Örn; Ingólfsson, Ólafur; Schomacker, Anders; Bergsdóttir, Helga Lucia; Jacobson Jr., William R.; Linderson, Hans (Journal article; Tidsskriftartikkel; Peer reviewed, 2016)
      Fláajökull is a non-surging outlet glacier draining the south-eastern part of the Vatnajökull, southeast Iceland. Fláajökull was stationary or advanced slightly between 1966 and 1995 and formed a prominent end moraine. Glacial retreat since then has revealed a cluster of 15 drumlins. This study focuses on the morphology and sedimentology of the drumlins. They are 100–600 m long, 40–130 m wide, and ...
    • Temperature observations from northernmost Greenland, 2006-2010 

      Schomacker, Anders; Larsen, Nicolaj K.; Bjørk, Anders A.; Kjær, Kurt H. (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-03-31)
      Air-, surface-, and subsurface temperatures were recorded by automatic weather stations in Bliss Bugt and Moore Gletscher, Johannes V. Jensen Land, North coast of Greenland from 2006-2010. The mean annual surface temperature is -12.1 ℃ in Bliss Bugt and -13.8 ℃ at Moore Gletscher. In 20 cm depth below the surface at Moore Gletscher, the mean annual temperature is -13.2 ℃ (2007-2008). High-amplitude ...