Evolution of the Norwegian-Greenland Sea

Total Page:16

File Type:pdf, Size:1020Kb

Evolution of the Norwegian-Greenland Sea Evolution of the Norwegian-Greenland Sea MANIK TALWANI Department of Geological Sciences and Lamont-Doherty Geological Observatory of Columbia University, Palisades, New York 10964 OLAV ELDHOLM* Lamont-Doherty Geological Observatory of Columbia University, Palisades, New York 10964 ABSTRACT Litvin, 1964, 1965; Johnson and Eckhoff, 1966; Johnson and Heezen, 1967; Vogt and others, 1970). A geological-geophysical Geological and geophysical data collected aboard R/V Verna dur- exploration of the Norwegian-Greenland Sea was carried out ing five summer cruises in the period 1966 to 1973 have been used aboard R/V Vema during the summers of 1966,1969, 1970, 1972, to investigate the geological history and evolution of the and 1973. The Vema tracks are shown in Figure 1. A primary ob- Norwegian-Greenland Sea. These data were combined with earlier jective of this exploration was the investigation of the geological data to establish the location of spreading axes (active as well as history and evolution of the Norwegian-Greenland Sea. To do so, it extinct), the age of the ocean floor from magnetic anomalies, and is necessary to identify the geological features that are related to the the locations and azimuths of fracture zones. The details of the process of sea-floor spreading. Thus, first, we need to know the lo- spreading history are then established quantitatively in terms of cations of the axes of the present spreading-ridge crest as well as the poles and rates of rotation. Reconstructions have been made to lo- location of extinct spreading axes. Second, we must know the loca- cate the relative positions of Norway and Greenland at various tions and azimuths of the fracture zones to define the direction of times since the opening, and the implications of these reconstruc- spreading. Third, we must determine, as precisely as possible, the tions are discussed here. boundaries of the oceanic crust — that is, the location of the lines of initial rifting, as well as the boundaries of any continental areas INTRODUCTION lying within the Norwegian-Greenland Sea. Fourth, we need to identify the magnetic lineations and thereby, by using a reversal The Norwegian-Greenland Sea has been the subject of several chronology, the age of the ocean crust asssociated with these linea- earlier surveys and investigations (Nansen, 1904; Stocks, 1950; tions. If these features can be determined, it is possible to describe -1 BO Figure 1. Tracks of R/V Vema during sum- men of 1966, 1969, 1970, 1972, and 1973 in Norwegian-Greenland Sea. 70 BO * Present address: Department of Geology, University of Oslo, Oslo, Norway. Geological Society of America Bulletin, v. 88, p. 969-999, 20 figs., July 1977, Doc. no. 70708. 969 Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/88/7/969/3429960/i0016-7606-88-7-969.pdf by guest on 02 October 2021 970 TALWANI AND ELDHOLM the evolution of the Norwegian-Greenland Sea in quantitative track by a notation such as 2704/2935. This indicates a location at terms. 2,935 mi along track on Vema cruise 27, leg 4. We have used our own data as well as the observations of previ- The term "Iceland Plateau" has been used by different authors in ous investigators to identify as many of the features listed above as different ways. Quite often, Iceland Plateau has been used for a possible, and we illustrate these with representative geophysical large area including Iceland, the Iceland-Jan Mayen Ridge, the Jan profiles. In this paper we denote a particular location along a ship's Mayen Ridge, and so forth. Purely for the sake of convenience, we 10° 5° 0° 5° 10° Figure 2. Physiographic and major structural features in Norwegian-Greenland Sea. Profiles I through VI of Figures 4A and 4B are located on this map. Earthquake epicenters are taken from Husebye and others (1975). Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/88/7/969/3429960/i0016-7606-88-7-969.pdf by guest on 02 October 2021 EVOLUTION OF THE NORWEGIAN-GREENLAND SEA 971 refer only to the area lying between the Iceland-Jan Mayen Ridge Iceland-Greenland Ridge (which connects Iceland to Greenland). and the Jan Mayen Ridge as the Iceland Plateau in this paper. Except for a thicker cover of sediments, one would expect it to be similar to the Iceland-Faeroe Ridge. MID-OCEANIC RIDGE The Iceland-Jan Mayen Ridge (Kolbeinsey Ridge) is also an un- usually shallow segment of the mid-oceanic ridge. Earlier studies From south to north, the mid-oceanic ridge consists of the fol- include detailed topographic, magnetic, and gravity surveys from lowing segments (Fig. 2): (1) Reykjanes Ridge, (2) Iceland, (3) Iceland to lat 70°N by Meyer and others (1972) and profiles of Iceland-Jan Mayen Ridge (also known as Kolbeinsey Ridge), (4) magnetics, topography, and seismic reflection between lat 69° and Mohns Ridge, and (5) Knipovich Ridge. 70°N by Johnson and others (1972). Vema seismic reflection data The Reykjanes Ridge southwest of Iceland has been studied ex- have also been discussed by Eldholm and Windisch (1974). The tensively (Ulrich, 1960; Heirtzler and others, 1966; Talwani and western flank is buried under terrigenous sediment derived from others, 1971; Fleischer, 1971; Herron and Talwani, 1972; Vogt Greenland. The axial relief is subdued near Iceland but pro- and Avery, 1974). North of about lat 58°N the Reykjanes Ridge is gressively increases northward. North of lat 67°N the axial magne- distinctive from the remainder of the North Atlantic mid-oceanic tic anomaly is clearly developed. Between lat 67°N and the Spar ridge in that it is unusually shallow but without an axial rift valley Fracture Zone at lat 69°N, the axial anomaly lies over an elevated and has a strikingly well-developed symmetrical magnetic anomaly feature at the axis. This is similar to the northern part of the Reyk- pattern. Prominent identified magnetic lineations lying in the area janes Ridge, where the axial rift is also absent. north of lat 60°N and east of long 30°W are shown in Figure 3. As North of the Spar Fracture Zone the ridge axis is offset to the Iceland and the Iceland-Faeroe Ridge are approached from the east. Between the Spar Fracture Zone and the fracture zone at lat south, the magnetic anomalies are less and less well developed. 70.5°N, a shallow but distinct axial rift is developed, in contrast However, the axial anomaly continues uninterruped into the Reyk- with the segment lying south of the Spar Fracture Zone. Thus, these janes Peninsula. Relative to anomaly 5, the axial anomaly is pro- two contiguous sections of the mid-oceanic ridge, which otherwise gressively shifted to the east as the Reykjanes Peninsula is ap- are similar, differ in this important property of whether there is a proached, implying a jump in the axis or the occurrence of asym- rift or a horst at the ridge crest. metric spreading (Talwani and others, 1971). The older anomalies Our identification of magnetic anomaly profiles to anomaly 5 is (19 to 24) associated with the Reykjanes Ridge are well developed. similar to that of Meyer and others (1972). In particular, we note On the east side, anomaly 24 lies close to Hatton Bank, and on the that anomaly 5 continues north without any offsets, even though west side it lies near the base of the slope off Greenland (Herron the Spar Fracture Zone offsets the crest at lat 69°N (Fig. 5), but the and Talwani, 1972). detailed pattern is not shown in this study. Our data show that Iceland as a part of the mid-oceanic ridge system has also been anomaly 5 appears to continue without any offset even north of the discussed widely in the literature. Recent estimates indicate a fracture zone at lat 70.5°N. Thus, the ridge axis was offset after maximum age of 20 m.y. (Dagley and others, 1967; Moorbath and anomaly 5 time. For the segment north of the Spar Fracture Zone, others, 1968) for Icelandic rocks. While the neovolcanic zone in Meyer and others (1972) have identified the time of the shift of the eastern Iceland is generally considered to be the principal center of ridge axis as 3 m.y. ago. Before and after the shift the spreading was spreading at the present time, Saemundsson (1974) and Palmason essentially symmetrical. Johnson and others (1972) correctly iden- (1974) have inferred that this spreading center has been active only tified anomaly 5 on the east side, but they did not detect the shift in for about the past 3 or 4 m.y. Before that time the western axis was the ridge axis and their identification of anomaly 5 on the west side the axis of spreading. Prior to the existence of Iceland, the corre- appears to be in error. If the correct anomaly 5 is used in computing sponding section of the mid-oceanic ridge formed what are now the spreading rates, there does not appear to be any serious asymmetry Iceland-Faeroe and Iceland-Greenland Ridges. in spreading rates. The Iceland-Faeroe Ridge is a smooth flat-topped relatively shal- Johnson and others (1972) also correlated a sequence of low ridge (with its crest at about 400 m) that connects Iceland with anomalies lying east of anomaly 5 between lat 69° and 70°N. They the Faeroe Islands. If Norway and Greenland have moved apart to considered a prominent minimum (one that we tentatively identify form the Norwegian Sea, with sea-floor spreading extending from as lying just west of the western anomaly 6 profile V, shown in Fig.
Recommended publications
  • Meltwater Routing and the Younger Dryas
    Meltwater routing and the Younger Dryas Alan Condrona,1 and Peter Winsorb aClimate System Research Center, Department of Geosciences, University of Massachusetts, Amherst, MA 01003; and bInstitute of Marine Science, School of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, AK 99775 Edited by James P. Kennett, University of California, Santa Barbara, CA, and approved September 27, 2012 (received for review May 2, 2012) The Younger Dryas—the last major cold episode on Earth—is gen- to correct another. A separate reconstruction of the drainage erally considered to have been triggered by a meltwater flood into chronology of North America by Tarasov and Peltier (8) found the North Atlantic. The prevailing hypothesis, proposed by Broecker that rather than being to the east, the geographical release point of et al. [1989 Nature 341:318–321] more than two decades ago, sug- meltwater to the ocean at this time might have been toward the gests that an abrupt rerouting of Lake Agassiz overflow through Arctic. Further support for a northward drainage route has since the Great Lakes and St. Lawrence Valley inhibited deep water for- been provided by Peltier et al. (9). Using a numerical model, the mation in the subpolar North Atlantic and weakened the strength authors showed that the response of the AMOC to meltwater of the Atlantic Meridional Overturning Circulation (AMOC). More re- placed directly over the North Atlantic (50° N to 70° N) and the cently, Tarasov and Peltier [2005 Nature 435:662–665] showed that entire Arctic Ocean were almost identical. This result implies that meltwater could have discharged into the Arctic Ocean via the meltwater released into the Arctic might be capable of cooling the Mackenzie Valley ∼4,000 km northwest of the St.
    [Show full text]
  • Baffin Bay Sea Ice Extent and Synoptic Moisture Transport Drive Water Vapor
    Atmos. Chem. Phys., 20, 13929–13955, 2020 https://doi.org/10.5194/acp-20-13929-2020 © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License. Baffin Bay sea ice extent and synoptic moisture transport drive water vapor isotope (δ18O, δ2H, and deuterium excess) variability in coastal northwest Greenland Pete D. Akers1, Ben G. Kopec2, Kyle S. Mattingly3, Eric S. Klein4, Douglas Causey2, and Jeffrey M. Welker2,5,6 1Institut des Géosciences et l’Environnement, CNRS, 38400 Saint Martin d’Hères, France 2Department of Biological Sciences, University of Alaska Anchorage, 99508 Anchorage, AK, USA 3Institute of Earth, Ocean, and Atmospheric Sciences, Rutgers University, 08854 Piscataway, NJ, USA 4Department of Geological Sciences, University of Alaska Anchorage, 99508 Anchorage, AK, USA 5Ecology and Genetics Research Unit, University of Oulu, 90014 Oulu, Finland 6University of the Arctic (UArctic), c/o University of Lapland, 96101 Rovaniemi, Finland Correspondence: Pete D. Akers ([email protected]) Received: 9 April 2020 – Discussion started: 18 May 2020 Revised: 23 August 2020 – Accepted: 11 September 2020 – Published: 19 November 2020 Abstract. At Thule Air Base on the coast of Baffin Bay breeze development, that radically alter the nature of rela- (76.51◦ N, 68.74◦ W), we continuously measured water va- tionships between isotopes and many meteorological vari- por isotopes (δ18O, δ2H) at a high frequency (1 s−1) from ables in summer. On synoptic timescales, enhanced southerly August 2017 through August 2019. Our resulting record, flow promoted by negative NAO conditions produces higher including derived deuterium excess (dxs) values, allows an δ18O and δ2H values and lower dxs values.
    [Show full text]
  • Recent Declines in Warming and Vegetation Greening Trends Over Pan-Arctic Tundra
    Remote Sens. 2013, 5, 4229-4254; doi:10.3390/rs5094229 OPEN ACCESS Remote Sensing ISSN 2072-4292 www.mdpi.com/journal/remotesensing Article Recent Declines in Warming and Vegetation Greening Trends over Pan-Arctic Tundra Uma S. Bhatt 1,*, Donald A. Walker 2, Martha K. Raynolds 2, Peter A. Bieniek 1,3, Howard E. Epstein 4, Josefino C. Comiso 5, Jorge E. Pinzon 6, Compton J. Tucker 6 and Igor V. Polyakov 3 1 Geophysical Institute, Department of Atmospheric Sciences, College of Natural Science and Mathematics, University of Alaska Fairbanks, 903 Koyukuk Dr., Fairbanks, AK 99775, USA; E-Mail: [email protected] 2 Institute of Arctic Biology, Department of Biology and Wildlife, College of Natural Science and Mathematics, University of Alaska, Fairbanks, P.O. Box 757000, Fairbanks, AK 99775, USA; E-Mails: [email protected] (D.A.W.); [email protected] (M.K.R.) 3 International Arctic Research Center, Department of Atmospheric Sciences, College of Natural Science and Mathematics, 930 Koyukuk Dr., Fairbanks, AK 99775, USA; E-Mail: [email protected] 4 Department of Environmental Sciences, University of Virginia, 291 McCormick Rd., Charlottesville, VA 22904, USA; E-Mail: [email protected] 5 Cryospheric Sciences Branch, NASA Goddard Space Flight Center, Code 614.1, Greenbelt, MD 20771, USA; E-Mail: [email protected] 6 Biospheric Science Branch, NASA Goddard Space Flight Center, Code 614.1, Greenbelt, MD 20771, USA; E-Mails: [email protected] (J.E.P.); [email protected] (C.J.T.) * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +1-907-474-2662; Fax: +1-907-474-2473.
    [Show full text]
  • The East Greenland Current North of Denmark Strait: Part I'
    The East Greenland Current North of Denmark Strait: Part I' K. AAGAARD AND L. K. COACHMAN2 ABSTRACT.Current measurements within the East Greenland Current during winter1965 showed that above thecontinental slope there were large on-shore components of flow, probably representing a westward Ekman transport. The speed did not decrease significantly with depth, indicatingthat the barotropic mode domi- nates the flow. Typical current speeds were10 to 15 cm. sec.-l. The transport of the current during winter exceeds 35 x 106 m.3 sec-1. This is an order of magnitude greater than previous estimates and, although there may be seasonal fluctuations in the transport, it suggests that the East Greenland Current primarily represents a circulation internal to the Greenland and Norwegian seas, rather than outflow from the central Polarbasin. RESUME. Lecourant du Groenland oriental au nord du dbtroit de Danemark. Aucours de l'hiver de 1965, des mesures effectukes danslecourant du Groenland oriental ont montr6 que sur le talus continental, la circulation comporte d'importantes composantes dirigkes vers le rivage, ce qui reprksente probablement un flux vers l'ouest selon le mouvement #Ekman. La vitesse ne diminue pas beau- coup avec laprofondeur, ce qui indique que le mode barotropique domine la circulation. Les vitesses typiques du courant sont de 10 B 15 cm/s-1. Au cows de l'hiver, le debit du courant dkpasse 35 x 106 m3/s-1. Cet ordre de grandeur dkpasse les anciennes estimations et, malgrC les fluctuations saisonnihres possibles, il semble que le courant du Groenland oriental correspond surtout B une circulation interne des mers du Groenland et de Norvhge, plut6t qu'8 un Bmissaire du bassin polaire central.
    [Show full text]
  • The Place of the Oceans in Norway's Foreign and Development Policy
    Norwegian Ministry of Foreign Affairs Published by: Meld. St. 22 (2016–2017) Report to the Storting (white paper) Norwegian Ministry of Foreign Affairs Public institutions may order additional copies from: Norwegian Government Security and Service Organisation The place of the oceans E-mail: [email protected] Internet: www.publikasjoner.dep.no KET T ER RY Telephone: + 47 222 40 000 M K Ø K J E L R in Norway's foreign and I I Photo: Peter Prokosch / Grid Arendal M 0 Print: 07 PrintMedia AS 7 9 7 P 3 R 0 I 1 N 4 08/2017 – Impression 500 TM 0 EDIA – 2 development policy 2016–2017 Meld. St. 22 (2016–2017) Report to the Storting (white paper) 1 The place of the oceans in Norway’s foreign and development policy Meld. St. 22 (2016–2017) Report to the Storting (white paper) The place of the oceans in Norway’s foreign and development policy Translation from Norwegian. For information only. Contents 1 Introduction................................... 5 Part III Priority areas for Norway ......... 41 2 Summary ....................................... 8 5 Sustainable use and value creation ......................................... 43 Part I Ocean interests ............................ 13 5.1 Oil and gas sector .......................... 43 5.1.1 International cooperation in the 3 Norwegian ocean interests in oil and gas sector ........................... 44 an international context ............ 15 5.2 Maritime industry .......................... 45 3.1 The potential of the oceans ........... 15 5.2.1 International cooperation in 3.2 Forces shaping international shipping .......................................... 45 ocean policy .................................... 16 5.2.2 Shipping in the north ..................... 47 3.3 Need for knowledge ....................... 17 5.3 Seafood industry ...........................
    [Show full text]
  • Sea Ice Volume Variability and Water Temperature in the Greenland Sea
    The Cryosphere, 14, 477–495, 2020 https://doi.org/10.5194/tc-14-477-2020 © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License. Sea ice volume variability and water temperature in the Greenland Sea Valeria Selyuzhenok1,2, Igor Bashmachnikov1,2, Robert Ricker3, Anna Vesman1,2,4, and Leonid Bobylev1 1Nansen International Environmental and Remote Sensing Centre, 14 Line V.O. 7, 199034 St. Petersburg, Russia 2Department of Oceanography, St. Petersburg State University, 10 Line V.O. 33, 199034 St. Petersburg, Russia 3Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Klumannstr. 3d, 27570 Bremerhaven, Germany 4Atmosphere-sea ice-ocean interaction department, Arctic and Antarctic Research Institute, Bering Str. 38, 199397 St. Petersburg, Russia Correspondence: Valeria Selyuzhenok ([email protected]) Received: 22 May 2019 – Discussion started: 26 June 2019 Revised: 21 November 2019 – Accepted: 4 December 2019 – Published: 5 February 2020 Abstract. This study explores a link between the long-term 1 Introduction variations in the integral sea ice volume (SIV) in the Green- land Sea and oceanic processes. Using the Pan-Arctic Ice The Greenland Sea is a key region of deep ocean convec- Ocean Modeling and Assimilation System (PIOMAS, 1979– tion (Marshall and Schott, 1999; Brakstad et al., 2019) and 2016), we show that the increasing sea ice volume flux an inherent part of the Atlantic Meridional Overturning Cir- through Fram Strait goes in parallel with a decrease in SIV in culation (AMOC) (Rhein et al., 2015; Buckley and Marshall, the Greenland Sea. The overall SIV loss in the Greenland Sea 2016).
    [Show full text]
  • MARITIME ACTIVITY in the HIGH NORTH – CURRENT and ESTIMATED LEVEL up to 2025 MARPART Project Report 1
    MARITIME ACTIVITY IN THE HIGH NORTH – CURRENT AND ESTIMATED LEVEL UP TO 2025 MARPART Project Report 1 Authors: Odd Jarl Borch, Natalia Andreassen, Nataly Marchenko, Valur Ingimundarson, Halla Gunnarsdóttir, Iurii Iudin, Sergey Petrov, Uffe Jacobsen and Birita í Dali List of authors Odd Jarl Borch Project Leader, Nord University, Norway Natalia Andreassen Nord University, Norway Nataly Marchenko The University Centre in Svalbard, Norway Valur Ingimundarson University of Iceland Halla Gunnarsdóttir University of Iceland Iurii Iudin Murmansk State Technical University, Russia Sergey Petrov Murmansk State Technical University, Russia Uffe Jakobsen University of Copenhagen, Denmark Birita í Dali University of Greenland 1 Partners MARPART Work Package 1 “Maritime Activity and Risk” 2 THE MARPART RESEARCH CONSORTIUM The management, organization and governance of cross-border collaboration within maritime safety and security operations in the High North The key purpose of this research consortium is to assess the risk of the increased maritime activity in the High North and the challenges this increase may represent for the preparedness institutions in this region. We focus on cross-institutional and cross-country partnerships between preparedness institutions and companies. We elaborate on the operational crisis management of joint emergency operations including several parts of the preparedness system and resources from several countries. The project goals are: • To increase understanding of the future demands for preparedness systems in the High North including both search and rescue, oil spill recovery, fire fighting and salvage, as well as capacities fighting terror or other forms of destructive action. • To study partnerships and coordination challenges related to cross-border, multi-task emergency cooperation • To contribute with organizational tools for crisis management Project characteristics: Financial support: -Norwegian Ministry of Foreign Affairs, -the Nordland county Administration -University partners.
    [Show full text]
  • Cop13 Inf. 66 (English Only / Únicamente En Inglés / Seulement En Anglais)
    CoP13 Inf. 66 (English only / únicamente en inglés / seulement en anglais) Written Statement by Japan on the naming of Sea of Japan In response to the written statement distributed by the RoK Delegation, Japan would like to present the pamphlet and related information on the appellation of the Sea of Japan, which show that the Sea of Japan is the standard appellation of the regional sea, and that all the UN publications shall exclusively use this specific appellation. Naming of the Sea of Japan The purpose of the United Nations Group of Experts on Geographical Names (UNGEGN) is to consider the technical problems of standardization of geographical names with a view to furthering it at both the national and international levels thereby preventing confusion in the use of names of geographical features. The delegation of Japan therefore believes that as a matter of principle it is not appropriate to discuss the issue of the naming of any particular geographical feature such as the Sea of Japan at this meeting. The views of the Government of Japan on this matter were clearly expressed at the previous sessions of the UNGEGN and the United Nations Conference on the Standardization of Geographical Names (UNCSGN), including its last session in Berlin in 2002, and have been duly recorded. It should be reiterated here that the name “Sea of Japan” is geographically and historically established and is used at present all over the world, except the ROK and the DPRK that claim the name should be replaced or at least co-named the “East Sea.” The following are the major points Japan wishes to make in response to these unfounded and politically motivated assertions.
    [Show full text]
  • Arctic Report Card 2017
    Arctic Report Card 2017 Arctic Report Card 2017 Arctic shows no sign of returning to reliably frozen region of recent past decades 2017 Headlines 2017 Headlines Video Executive Summary Contacts Arctic shows no sign of returning to reliably frozen Vital Signs region of recent past decades Surface Air Temperature Despite relatively cool summer temperatures, Terrestrial Snow Cover observations in 2017 continue to indicate that the Greenland Ice Sheet Arctic environmental system has reached a 'new Sea Ice normal', characterized by long-term losses in the Sea Surface Temperature extent and thickness of the sea ice cover, the extent Arctic Ocean Primary Productivity and duration of the winter snow cover and the mass of ice in the Greenland Ice Sheet and Arctic glaciers, Tundra Greenness and warming sea surface and permafrost Other Indicators temperatures. Terrestrial Permafrost Groundfish Fisheries in the Highlights Eastern Bering Sea Wildland Fire in High Latitudes • The average surface air temperature for the year ending September 2017 is the 2nd warmest since 1900; however, cooler spring and summer temperatures contributed to a rebound in snow cover in the Eurasian Arctic, slower summer sea ice loss, Frostbites and below-average melt extent for the Greenland ice sheet. Paleoceanographic Perspectives • The sea ice cover continues to be relatively young and thin with older, thicker ice comprising only 21% of the ice cover in on Arctic Ocean Change 2017 compared to 45% in 1985. Collecting Environmental • In August 2017, sea surface temperatures in the Barents and Chukchi seas were up to 4° C warmer than average, Intelligence in the New Arctic contributing to a delay in the autumn freeze-up in these regions.
    [Show full text]
  • Norway in Respect of Areas in the Arctic Ocean, the Barents Sea and the Norwegian Sea Executive Summary
    Continental Shelf Submission of Norway in respect of areas in the Arctic Ocean, the Barents Sea and the Norwegian Sea Executive Summary 50˚00’ 85˚00’ 45˚00’ 40˚00’ 35˚00’ Continental shelf 30˚00’ 30˚00’ 200 nautical mile limit of Norway beyond 200 nautical 85˚00’ 25˚00’ 25˚00’ 20˚00’ 20˚00’ miles 15˚00’ 15˚00’ 200 nautical mile limits of other states 10˚00’5˚00’ 0˚00’ 5˚00’10˚00’ Bilateral maritime boundaries between Water depth Norway and other states 0 meter Computed median line between 500 meter Norway and the Russian Federation 1000 meter Western 80˚00’ Nansen Basin Preliminary line connecting continental 1500 meter shelf outer limit points of Norway and the Russian Federation 2000 meter Outer limit of the continental shelf 2500 meter beyond 200 nautical miles 3000 meter 2500 meter isobath 3500 meter 80˚00’ Yermak BARENTS Land boundaries between states 4000 meter Plateau Boundary between 200 nautical mile 4500 meter SEA 75˚00’ zones of Mainland Norway and around Svalbard 5000 meter 5500 meter Land Svalbard Continental shelf outer limit points Norwegian territory 60 nautical mile distance criterion Sediment thickness criterion Land, undifferentiated Knipovich Ridge Loop Greenland Hole Point of the Russian Federation 75˚00’ 70˚00’ GREENLAND SEA Bjørnøya 65˚00’ 70˚00’ Mohns Ridge Jan Mayen 60˚00’ NORWEGIAN 50˚00’ Lofoten Jan Mayen Fracture Zone SEA Basin Iceland SEAVøring Spur Jan Mayen Micro Continent Banana Hole Plateau Banana Hole 65˚00’ 45˚00’ Vøring Russian Federation Norway Plateau Basin 40˚00’ Iceland Finland 35˚00’ 60˚00’ 30˚00’
    [Show full text]
  • Dynamic Ocean Topography of the Greenland Sea: a Comparison Between Satellite Altimetry and Ocean Modeling Felix L
    The Cryosphere Discuss., https://doi.org/10.5194/tc-2018-184 Manuscript under review for journal The Cryosphere Discussion started: 22 October 2018 c Author(s) 2018. CC BY 4.0 License. Dynamic Ocean Topography of the Greenland Sea: A comparison between satellite altimetry and ocean modeling Felix L. Müller1, Claudia Wekerle2, Denise Dettmering1, Marcello Passaro1, Wolfgang Bosch1, and Florian Seitz1 1Deutsches Geodätisches Forschungsinstitut, Technische Universität München, Arcisstraße 21, 80333 Munich, Germany 2Climate Dynamics, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bussestraße 24, 27570 Bremerhaven, Germany Correspondence: Felix L. Müller ([email protected]) Abstract. The dynamic ocean topography (DOT) in the polar seas can be described by satellite altimetry sea surface height observations combined with geoid information and by ocean models. The altimetry observations are characterized by an irregular sampling and seasonal sea-ice coverage complicating reliable DOT estimations. Models display various spatio-temporal resolutions, 5 but are limited to their computational and mathematical context and introduced forcing models. In the present paper, ALES+ retracked altimetry ranges and derived along-track DOT heights of ESA’s Envisat and water heights of the Finite Element Sea- ice Ocean Model (FESOM) are compared to investigate similarities and discrepancies. The study period covers the years 2003- 2009. An assessment analysis regarding seasonal DOT variabilities shows good accordance and confirms the most dominant impact of the annual signal in both datasets. A comparison based on estimated regional annual signal components shows 2-3 10 times stronger amplitudes of the observations but good agreement of the phase. Reducing both datasets by constant offsets and the annual signal reveals small regional residuals and highly correlated DOT time series (correlation coefficient at least 0.67).
    [Show full text]
  • Arctic Report Card 2018 Effects of Persistent Arctic Warming Continue to Mount
    Arctic Report Card 2018 Effects of persistent Arctic warming continue to mount 2018 Headlines 2018 Headlines Video Executive Summary Effects of persistent Arctic warming continue Contacts to mount Vital Signs Surface Air Temperature Continued warming of the Arctic atmosphere Terrestrial Snow Cover and ocean are driving broad change in the Greenland Ice Sheet environmental system in predicted and, also, Sea Ice unexpected ways. New emerging threats Sea Surface Temperature are taking form and highlighting the level of Arctic Ocean Primary uncertainty in the breadth of environmental Productivity change that is to come. Tundra Greenness Other Indicators River Discharge Highlights Lake Ice • Surface air temperatures in the Arctic continued to warm at twice the rate relative to the rest of the globe. Arc- Migratory Tundra Caribou tic air temperatures for the past five years (2014-18) have exceeded all previous records since 1900. and Wild Reindeer • In the terrestrial system, atmospheric warming continued to drive broad, long-term trends in declining Frostbites terrestrial snow cover, melting of theGreenland Ice Sheet and lake ice, increasing summertime Arcticriver discharge, and the expansion and greening of Arctic tundravegetation . Clarity and Clouds • Despite increase of vegetation available for grazing, herd populations of caribou and wild reindeer across the Harmful Algal Blooms in the Arctic tundra have declined by nearly 50% over the last two decades. Arctic • In 2018 Arcticsea ice remained younger, thinner, and covered less area than in the past. The 12 lowest extents in Microplastics in the Marine the satellite record have occurred in the last 12 years. Realms of the Arctic • Pan-Arctic observations suggest a long-term decline in coastal landfast sea ice since measurements began in the Landfast Sea Ice in a 1970s, affecting this important platform for hunting, traveling, and coastal protection for local communities.
    [Show full text]