Towards a process-based biogeography of reindeer—scaling space,time, and organizational levels of space use

Due to increasing anthropogenic habitat alteration, fragmentation, and loss, the analysis of how, when, and why animals select particular habitats has become a central issue in ecology and biogeography. Animals adapt to spatiotemporal variability in resources either by tracking these resources or by plasticity in behavior to cover their needs, leading to three important implications: movement, temporal variation, and individual trade-offs leading to intra-species variability, all of which are directly linked to the use of space by animals. Based on GPS-tracking of domesticated reindeer in southern Norway, the authors addressed these issues by analyzing movement patterns and space use simultaneously across different temporal and organizational scales. Emerging information about the space use by reindeer was found explicitly linked to scaling relations, reflecting the matter of scale as having important functional implications rather than solely being a technical question of extent and resolution. Adding movement into the analysis of space use further advances the necessary functional perspective on space use. The authors conclude that scaling not only space but also time and the organizational level, in combination with accounting for different behavioral states, brings biogeography closer to a process-based view, rather than solely pattern-based view.     

Erosion and morphology of a debris flow caused by a glacial lake outburst flood,Western Norway

This article documents a 240,000-m³ debris flow resulting from a glacial lake outburst flood in Fjærland, Western Norway, May 8, 2004. The event started when a glacial lake breached a moraine ridge. The ensuing debris flow was able to erode material along its path, increasing in volume from about 25,000 to 240,000 m³ before depositing about 3 km from its starting point. Field investigations, pre- and post-flow aerial photographs as well as airborne laser scanning (LIDAR) were used to describe and investigate the flow. The most striking and unusual feature of this case study is the very pronounced erosion and bulking. We have made a detailed study of this aspect. Erosion and entrainment is quantified and the final volume of the debris flow is determined. We also present geometrical and sedimentological features of the final deposit. Based on the Fjærland data, we suggest that a self-sustaining mechanism might partly explain the extreme growth of debris flows traversing soft terrain.     

The uncertainties of precaution: Zero discharges in the Barents Sea

This paper describes and analyzes the application of the precautionary principle in the regulation of operational discharges from offshore petroleum activities. Norway implemented a zero discharge policy in line with international agreements. However, companies are obliged to follow considerably stricter requirements in the Barents Sea compared to other parts of the Norwegian Continental Shelf. This paper follows the development of the zero discharge measure and analyzes what it implies for activities in the Barents Sea. Several “uncertainties of precaution” are discussed, which relate to technological issues, monitoring, compliance and unintended environmental consequences. Precautionary action should be scrutinized for its proportionality: how do the benefits of the measure relate to the technological, financial and environmental costs? It is concluded that the most (cost-) effective solutions that could lead to the lowest total environmental harm are not always the solutions that are most politically feasible.     

Late‐glacial to Holocene environmental changes and climate variability: evidence from Voldafjorden,western Norway

Sedimentological, micropalaeontological (benthic foraminifers and dinoflagellate cysts), stable isotope data and AMS ¹⁴C datings on cores and surface samples, in addition to acoustic data, have been obtained from Voldafjorden, western Norway. Based on these data the late glacial and Holocene sedimentological processes and variability in circulation and fjord environments are outlined. Glacial marine sedimentation prevailed in the Voldafjorden between 11.0 kyr and 9.2 kyr BP (radiocarbon years). In the later part of the Allerød period, and for the rest of the Holocene, there was deposition of fine‐grained normal marine sediments in the fjord basin. Turbidite layers, recorded in core material and on acoustic profiles, dated to ca. 2.1, 6.9–7.6, ca. 9.6 and ca. 11.0 kyr BP, interrupted the marine sedimentation. The event dated to between 6.9 and 7.6 kyr BP probably corresponds to a tsunami resulting from large‐scale sliding on the continental margin off Norway (the Storegga Tsunami). During the later part of the Allerød period, Voldafjorden had a strongly stratified water column with cold bottom water and warm surface water, reaching interglacial temperatures during the summer seasons. During the Younger Dryas cold event there was a return to arctic sea‐surface summer temperatures, possibly with year‐round sea‐ice cover, the entire benthic fauna being composed of arctic species. The first strong Holocene warming, observed simultaneously in bottom and sea‐surface temperature proxies, occurred at ca. 10.1 kyr BP. Bottom water proxies indicate two cold periods, possibly with 2°C lowering of temperatures, at ca. 10.0 (PBO 1) and at 9.8 kyr BP (PBO 2). These events may both result from catastrophic outbursts of Baltic glacial lake water. The remainder of the Holocene experienced variability in basin water temperature, indicated by oxygen isotope measurements with an amplitude of ca. 2°C, with cooler periods at ca. 8.4–9.0, 5.6, 5.2, 4.6, 4.2, 3.5, 2.2, 1.2 and 0.4–0.8 kyr BP. Changes in the fjord hydrology through the past 11.3 kyr show a close correspondence, both in amplitude and timing of events, recorded in cores from the Norwegian Sea region and the North Atlantic. These data suggest a close relationship between fjord environments and variability in large‐scale oceanic circulation. Copyright © 2001 John Wiley & Sons, Ltd.     

Acidity and organic carbon in lake water: variability and estimation of means

The demand for a single value to characterize the pH (and other chemical variables) of a lake, in order to calibrate palaeolimnological reconstructions, requires an answer to the question of whether means should be of untransformed or log data. The temporal frequency distributions of acidity and organic carbon in seven rivers and lakes (surface samples) in Norway are approximately lognormal. Thus log means describe the distributions better than untransformed means. Estimated standard deviations, which are similar for the rivers and lakes, are independent of the mean values. Restricting observations to the autumn does not result in better estimation of mean annual values.     

Discovery of eclogite facies carbonate rocks from the Lindås Nappe, Caledonides, Western Norway

Eclogite facies carbonate rocks have been discovered associated with the granulite–eclogite transitional rocks within Bergen Arc system, Caledonian Orogen of western Norway. The local occurrences of marbles and calc‐silicates are found subparallel to the mafic eclogite facies shear zones on Holsnøy Island. Marbles contain the assemblage calcite (Ca_0.99Sr_0.01CO₃), calcian strontianite (Ca_0.18?0.44Sr_0.53?0.84CO₃), clinopyroxene (Jd_7?32), epidote/allanite (Ps_0?33), titanite, garnet (Alm_52?56Grs_28?33Pyp_11?16), barite (Ba_0.90?0.99Sr_0.01?0.10SO₄), celestine (Sr_0.67?0.98Ba_0.01?0.23Ca_0.01?0.11SO₄), and one apparently homogeneous grain of intermediate composition (Ba_0.49Ca_0.01Sr_0.50SO₄). Adjacent eclogites have clinopyroxene with similar jadeite contents (Jd_14?34) and similar garnet (Alm_51?60Grs_26?36Pyp_8?14) compositions. The marbles have high contents of Sr (9500–11000 p.p.m) and Y (115–130 p.p.m). However, low concentrations of some key trace elements (110–160 p.p.m. Ba and <5 p.p.m. Nb) appear to indicate that the marble is not a metamorphosed carbonatite. The ⁸⁷Sr/⁸⁶Sr ratios range from 0.7051 to 0.7059. Field and petrological relationships suggest that metasomatic reactions and fluids played a significant role in producing and/or modifying the marbles. The breakdown of scapolite in the granulite into carbonates and sulphates during eclogite facies metamorphism may have contributed to the metasomatic formation of the marbles along shear zones. Fluids involved during subduction are an important catalyst for metamorphism and are recognized to have played a critical role in the localized transformation from granulite to eclogite in the Holsnøy Island area. Thermobarometry indicates 640–690 °C and 18–20 kbar for adjacent eclogites and temperatures of 580–650 °C for the calc‐silicates. The marble assemblages are consistent with fluid that is dominantly comprised of H₂O (X_CO2 < 0.03) under high‐pressure conditions. Phase equilibria of the marbles constrain the fO₂ of the fluids and imply oxidizing conditions of the deep crustal fluids. At present the source of the fluids remains unresolved. The results provide additional insights into the variable and evolving nature of fluids related to subduction and high‐pressure metamorphism.     

Late Weichselian and Holocene sediment flux and sedimentation rates in Andfjord and Vågsfjord,North Norway

Late Weichselian and Holocene sediment flux and sedimentation rates in a continental‐shelf trough, Andfjord, and its inshore continuation, Vågsfjord, North Norway, have been analysed. The study is based on sediment cores and high‐resolution acoustic data. Andfjord was deglaciated between 14.6 and 13 ¹⁴C kyr BP (17.5 and 15.6 calibrated (cal.) kyr BP), the Vågsfjord basin before 12.5 ¹⁴C kyr BP (14.7 cal. kyr BP), and the heads of the inner tributary fjords about 9.7 ¹⁴C kyr BP (11.2 cal. kyr BP). In Andfjord, five seismostratigraphical units are correlated to a radiocarbon dated lithostratigraphy. Three seismostratigraphical units are recognised in Vågsfjord. A total volume of 23 km³ post‐glacial glacimarine and marine sediments was mapped in the study area, of which 80% are of Late Weichselian origin. Sedimentation rates in outer Andfjord indicate reduced sediment accumulation with increasing distance from the ice margin. The Late Weichselian sediment flux and sedimentation rates are significantly higher in Vågsfjord than Andfjord. Basin morphology, the position of the ice front and the timing of deglaciation are assumed to be the reasons for this. Late Weichselian sedimentation rates in Andfjord and Vågsfjord are comparable to modern subpolar glacimarine environments of Greenland, Baffin Island and Spitsbergen. Downwasting of the Fennoscandian Ice Sheet, and winnowing of the banks owing to the full introduction of the Norwegian Current, caused very high sedimentation rates in parts of the Andfjord trough at the Late Weichselian–Holocene boundary. Holocene sediment flux and sedimentation rates in Andfjord are about half the amount found in Vågsfjord, and about one‐tenth the amount of Late Weichselian values. A strong bottom current system, established at the Late Weichselian–Holocene boundary, caused erosion of the Late Weichselian sediments and an asymmetric Holocene sediment distribution. Copyright © 2002 John Wiley & Sons, Ltd.     

Temporal englacial water content variability associated with a rapidly retreating glacier

This study uses a combination of evidence from ground penetrating radar, borehole, video, and wireless probe data to assess temporal changes in englacial water content associated with Briksdalsbreen, a rapidly retreating Norwegian glacier. Over a 13 day period in 2006, ice radar‐wave velocity varied between 0·135 m/ns (± 0·009) and 0·159 m/ns (± 0·003), and water content from 7·8% (+2·6, ?2·8) to 2·5% (+0·9, ?1·1) [derived from the Looyenga (Physica 31 (3): 401–406, 1965) formula]. It is suggested that during warm precipitation free days, void spaces within the glacier become filled with water, resulting in low radar‐wave velocity. This stored water then drained during cold, high precipitation days, allowing the radar‐wave velocity to rise. These changes in englacial storage were caused by the enhanced crevassing generated by the newly floating ice margin, and were associated with accelerated glacier retreat. Copyright © 2011 John Wiley & Sons, Ltd.