Why Do They Need the Arctic? the First Partition of the Sea WOJCIECH JANICKI1
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Bathymetry and Deep-Water Exchange Across the Central Lomonosov Ridge at 88–891N
ARTICLE IN PRESS Deep-Sea Research I 54 (2007) 1197–1208 www.elsevier.com/locate/dsri Bathymetry and deep-water exchange across the central Lomonosov Ridge at 88–891N Go¨ran Bjo¨rka,Ã, Martin Jakobssonb, Bert Rudelsc, James H. Swiftd, Leif Andersone, Dennis A. Darbyf, Jan Backmanb, Bernard Coakleyg, Peter Winsorh, Leonid Polyaki, Margo Edwardsj aGo¨teborg University, Earth Sciences Center, Box 460, SE-405 30 Go¨teborg, Sweden bDepartment of Geology and Geochemistry, Stockholm University, Stockholm, Sweden cFinnish Institute for Marine Research, Helsinki, Finland dScripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA eDepartment of Chemistry, Go¨teborg University, Go¨teborg, Sweden fDepartment of Ocean, Earth, & Atmospheric Sciences, Old Dominion University, Norfolk, USA gDepartment of Geology and Geophysics, University of Alaska, Fairbanks, USA hPhysical Oceanography Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA iByrd Polar Research Center, Ohio State University, Columbus, OH, USA jHawaii Institute of Geophysics and Planetology, University of Hawaii, HI, USA Received 23 October 2006; received in revised form 9 May 2007; accepted 18 May 2007 Available online 2 June 2007 Abstract Seafloor mapping of the central Lomonosov Ridge using a multibeam echo-sounder during the Beringia/Healy–Oden Trans-Arctic Expedition (HOTRAX) 2005 shows that a channel across the ridge has a substantially shallower sill depth than the 2500 m indicated in present bathymetric maps. The multibeam survey along the ridge crest shows a maximum sill depth of about 1870 m. A previously hypothesized exchange of deep water from the Amundsen Basin to the Makarov Basin in this area is not confirmed. -
One of Deep Ocean's Most Turbulent Areas Has Big Impact on Climate 9 August 2007
One of Deep Ocean's Most Turbulent Areas Has Big Impact on Climate 9 August 2007 small passageways of such mountains is generating much of the mixing of warm and cold waters in the Atlantic Ocean. Better understanding of the mechanisms of mixing is crucial, says St. Laurent, an assistant professor of physical oceanography at FSU and the study’s co-principal investigator, because mixing produces the overall balance of water temperatures that helps control the strength of the Gulf Stream -- the strong, warm ocean current that starts in the Gulf of Mexico, flows along the U.S. east coast to Canada and on to Europe, and plays a crucial climate role. “Oceanographers are working hard to understand how processes in the ocean help to keep the Earth’s climate stable,” St. Laurent said. “We are aware that the climate is warming, but we don’t yet fully understand how the changes will affect Profiler. Credit: Florida State University society. Our work will result in better models for predicting how the ocean will affect the climate in the future and a better understanding of sea-level rise, weather patterns such as El Nino, and the More than a mile beneath the Atlantic’s surface, impact of these events on fisheries.” roughly halfway between New York and Portugal, seawater rushing through the narrow gullies of an St. Laurent compared the flow of seawater through underwater mountain range much as winds gust underwater gullies in the Mid-Atlantic Ridge to the between a city’s tall buildings is generating one of wind, so familiar to hikers, that blows through the most turbulent areas ever observed in the deep mountain passages on land. -
Age and Origin of the Lomonosov Ridge: a Key Continental Fragment in Arctic Ocean Reconstructions
Geophysical Research Abstracts Vol. 17, EGU2015-10207-1, 2015 EGU General Assembly 2015 © Author(s) 2015. CC Attribution 3.0 License. Age and origin of the Lomonosov Ridge: a key continental fragment in Arctic Ocean reconstructions Christian Marcussen, Christian Knudsen, John R. Hopper, Thomas Funck, Jon R. Ineson, and Morten Bjerager Geological Survey of Denmark and Greenland (GEUS), Copenhagen, Denmark The Lomonosov Ridge is a trans-oceanic seafloor high that separates the Eurasia Basin from the Amerasia Basin. It extends for a distance of almost 1800 km across the Arctic Ocean from the Lincoln Shelf off Greenland and Canada to the East Siberian Shelf. Although known from the ACEX drilling expedition to be a sliver of continental crust, it remains an enigmatic feature and many details of its history are unknown. In the summer of 2012, GEUS recovered dredge samples from two locations along the flank of the ridge facing the Eurasian Basin. The samples comprise 100 kg and 200 kg of rocks and rock pieces ranging in size from 0.1 to 80 kg which were recovered from two different scarps associated with rotated continental fault blocks. A significant quantity of rocks with identical structures and isotopic fingerprints show that they formed at the same time and from the same geological material. This combined with the broken and angular nature of many of the pieces recovered indicates that the material is from in situ bedrock and does not represent dropstones brought to the area by drifting ice. Two main sedimentary rock types were recovered - an arkosic metasedimentary rock, and a quartz rich non-metamorphic sandstone. -
A Comprehensive Geospatial Assessment of Seagrass Distribution in India
Ocean and Coastal Management xxx (xxxx) xxx–xxx Contents lists available at ScienceDirect Ocean and Coastal Management journal homepage: www.elsevier.com/locate/ocecoaman A comprehensive geospatial assessment of seagrass distribution in India ∗ Gejo Anna Geevarghese , B. Akhil, G. Magesh, P. Krishnan, R. Purvaja, R. Ramesh National Centre for Sustainable Coastal Management (NCSCM), Ministry of Environment, Forest and Climate Change, Government of India, Anna University Campus, Chennai 600025, India ARTICLE INFO ABSTRACT Keywords: The study deals with the first comprehensive spatial distribution and area estimate of seagrass patches of India Area estimate with a standardized methodology. Seagrass patches are mainly located in Palk Bay – Gulf of Mannar (Tamil Landsat 8 OLI Nadu), Gulf of Kachchh (Gujarat), Chilika Lake (Odisha) and Islands of Andaman & Nicobar and Lakshadweep. fi Digital classi cation Medium resolution satellite images of Landsat 8 OLI were subjected to radiometric, atmospheric and water Seagrass column correction prior to digital classification and contextual editing. Total estimated seagrass area amounts to Water column correction 516.59 km2 of which Palk Bay and Gulf of Mannar of Tamil Nadu together contribute to 398.81 km2. Overall classification accuracy for the six sites studied, ranged between 64% (Lakshadweep Islands) and 83.5% (Palk Bay). This suggests that for surveillance studies of homogeneous seagrass meadows with low interspersion of other benthic units such as corals, seaweeds etc., digital mapping using medium resolution data sets with mandatory attenuation correction procedures is suitable. The results of this study and the related area statistics were accepted as a baseline at national level for the delineation of Ecologically Sensitive Areas (ESA) and in the formulation of its conservation strategies. -
Geographic Names
Commentary THE FLOOR OF THE ARCTICOCEAN: GEOGRAPHIC NAMES M. A. Beall, F. Edvalson2, K. Hunkins3, A. Molloyl, and N. Ostenso4 HE NAMING OF OCEAN FLOOR features in the Arctic seems to have been done Twithout thought to standardization in geographic nomenclature. W. K. Lyon, Director of the Arctic Sciences and Technology Division of the US.Navy Electronics Laboratory, called a meeting of the authors of the present paper to arbitrate the naming of these features in the hope that it would help to stem the proliferation of new namesand to standardize the names of the major features. The decisions of the meeting which was held in San Diego on 10 and 11 January 1966 were based on the following criteria: 1. Consistency with the Undersea terms and definitions proposed by the Advisory Committee on Undersea Features to the U.S. Board on Geo- graphicNames (Washington, D.C.: 1964) andLimits of Oceans and Seas, InternationalHydrographic Bureau Special PublicationNo. 23 (Monte Carlo: 1953) 2. Common usage 3. Priority of discovery or naming 4. Association withestablished geographic features 5. Minimizing ambiguity Fifty-four major features were discussed. Table 1 lists the names considered, the final suggested name, the approximate location, and the status of the name with the U.S. Board on Geographic Names and the International Hydrographic Bureau. The final suggested names represent the majority decision of the authors but it should be noted that in certain cases there was not complete unanimity. For the most part, however, it it felt that the accepted names should raise little controversy. The authors will endeavour to use the final suggested namesin future publications, and it is hoped that other investigatorswill find them suitable for their use. -
Redacted for Privacy Abstract Approved: John V
AN ABSTRACT OF THE THESIS OF MIAH ALLAN BEAL for the Doctor of Philosophy (Name) (Degree) in Oceanography presented on August 12.1968 (Major) (Date) Title:Batymety and_Strictuof_thp..4rctic_Ocean Redacted for Privacy Abstract approved: John V. The history of the explordtion of the Central Arctic Ocean is reviewed.It has been only within the last 15 years that any signifi- cant number of depth-sounding data have been collected.The present study uses seven million echo soundings collected by U. S. Navy nuclear submarines along nearly 40, 000 km of track to construct, for the first time, a reasonably complete picture of the physiography of the basin of the Arctic Ocean.The use of nuclear submarines as under-ice survey ships is discussed. The physiography of the entire Arctic basin and of each of the major features in the basin are described, illustrated and named. The dominant ocean floor features are three mountain ranges, generally paralleling each other and the 40°E. 140°W. meridian. From the Pacific- side of the Arctic basin toward the Atlantic, they are: The Alpha Cordillera; The Lomonosov Ridge; andThe Nansen Cordillera. The Alpha Cordillera is the widest of the three mountain ranges. It abuts the continental slopes off the Canadian Archipelago and off Asia across more than550of longitude on each slope.Its minimum width of about 300 km is located midway between North America and Asia.In cross section, the Alpha Cordillera is a broad arch rising about two km, above the floor of the basin.The arch is marked by volcanoes and regions of "high fractured plateau, and by scarps500to 1000 meters high.The small number of data from seismology, heat flow, magnetics and gravity studies are reviewed.The Alpha Cordillera is interpreted to be an inactive mid-ocean ridge which has undergone some subsidence. -
When the Earth Moves Seafloor Spreading and Plate Tectonics
This article was published in 1999 and has not been updated or revised. BEYONDBEYOND DISCOVERYDISCOVERYTM THE PATH FROM RESEARCH TO HUMAN BENEFIT WHEN THE EARTH MOVES SEAFLOOR SPREADING AND PLATE TECTONICS arly on the morning of Wednesday, April 18, the fault had moved, spanning nearly 300 miles, from 1906, people in a 700-mile stretch of the West San Juan Bautista in San Benito County to the south E Coast of the United States—from Coos Bay, of San Francisco to the Upper Mattole River in Oregon, to Los Angeles, California—were wakened by Humboldt County to the north, as well as westward the ground shaking. But in San Francisco the ground some distance out to sea. The scale of this movement did more than shake. A police officer on patrol in the was unheard of. The explanation would take some six city’s produce district heard a low rumble and saw the decades to emerge, coming only with the advent of the street undulate in front of him, “as if the waves of the theory of plate tectonics. ocean were coming toward me, billowing as they came.” One of the great achievements of modern science, Although the Richter Scale of magnitude was not plate tectonics describes the surface of Earth as being devised until 1935, scientists have since estimated that divided into huge plates whose slow movements carry the the 1906 San Francisco earthquake would have had a continents on a slow drift around the globe. Where the 7.8 Richter reading. Later that morning the disaster plates come in contact with one another, they may cause of crushed and crumbled buildings was compounded by catastrophic events, such as volcanic eruptions and earth- fires that broke out all over the shattered city. -
Quaternary Stratigraphy of the Northwind Ridge, Arctic Ocean
Quaternary Stratigraphy of the Northwind Ridge, Arctic Ocean THESIS Presented in Partial Fulfillment of the Requirements for the Degree Master of Science in the Graduate School of The Ohio State University By Kevin Allen Crawford B.S. Graduate Program in Geological Sciences The Ohio State University 2010 Master's Examination Committee: Peter-Noel Webb, Advisor Leonid Polyak Lawrence A. Krissek Copyright by Kevin A Crawford 2010 Abstract The Arctic Ocean plays an important role in modulating the world‘s climate. Changes in sea-ice albedo and the export of freshwater into the North Atlantic could have serious repercussions to the climate patterns far beyond the Arctic. To understand fully the impacts of the retreating sea-ice cover and the warming Arctic Ocean we need to look into the past for clues. Paleoenvironments of the Arctic Ocean can be reconstructed by using sea-floor sediment constituents, such as paleobiological and mineral components as well as chemical and paleomagnetic parameters. Three cores raised from the Northwind Ridge, north of the Alaskan continental margin, were chosen to investigate sedimentary patterns and related paleoenvironments in the western Arctic Ocean across a time frame from the Holocene to estimated early Pleistocene. These cores show a range of sedimentation rates decreasing from south to north, thus allowing a development of a relatively high-resolution Upper Quaternary stratigraphy at the southern part of the ridge and a lower-resolution, yet longer stratigraphy for its northern part. In addition to this long stratigraphic coverage, the northern core has well-preserved calcareous microfauna, which provides new insights into paleoceanographic environments. -
On Thin Ice? (Mis)Interpreting Russian Policy in the High North Roderick Kefferpütz
No. 205/February 2010 On Thin Ice? (Mis)interpreting Russian Policy in the High North Roderick Kefferpütz limate change in the Arctic is expected to make the ice cap dwindling to a record-low minimum extent the region a lot busier as new strategic of 4.3 million square km in September 2007.2 resources become available. The Russian C These developments open up an array of intractable Federation is a key player in this context, having put challenges, including threats to biodiversity and the forth a comprehensive Arctic strategy. Russian policy traditional way of life of autochthon communities in towards the so-called High North, however, is the Arctic region. Of particular danger to global oftentimes not seen in its entirety and has received a environmental stability, however, is the threat to low- plethora of criticism in the Western media and foreign lying coastal regions posed by rising sea levels. This policy community. This paper aims to contribute to a would not only have immense political, environmental better understanding of Russian actions in the High and social consequences; the economic effects would North by providing a succinct overview of Russian also be tremendous. According to Allianz financial policies in the region and identifying the fundamental services, a rise of half a metre by the middle of this rationale behind them. The paper concludes that century could put at risk more than 28 trillion dollars’ Russia’s Arctic policy is not only a lot more nuanced worth of assets in the world’s largest coastal cities.3 In but also not very different from the policies conducted addition, increasing temperatures in this volatile region by other riparian states. -
Gchron-2019-16.Pdf
https://doi.org/10.5194/gchron-2019-16 Preprint. Discussion started: 7 November 2019 c Author(s) 2019. CC BY 4.0 License. A new 30,000 year chronology for rapidly deposited sediments on the Lomonosov Ridge using bulk radiocarbon dating and probabilistic stratigraphic alignment Francesco Muschitiello1, Matt O’Regan2, Jannik Martens3, Gabriel West2, Örjan Gustafsson3, Martin 5 Jakobsson2 1 Department of Geography, University of Cambridge, Cambridge CB2 3EN, UK 2 Department of Geological Sciences, Stockholm University, Svante Arrhenius väg 8, SE 106 91, Sweden 3 Department of Environmental Science and Analytical Chemistry, Stockholm University, Svante Arrhenius väg 8, SE 106 91, Sweden 10 Correspondence to: Francesco Muschitiello ([email protected]) Abstract. We present a new marine chronostratigraphy from a high-accumulation rate Arctic Ocean core at the intersection of the Lomonosov Ridge and the Siberian margin, spanning the last ~30 kyr. The chronology was derived using a combination of bulk 14C dating and stratigraphic correlation to Greenland ice-core records. This was achieved by applying an appositely developed Markov chain Monte Carlo algorithm for Bayesian probabilistic alignment of proxy records. The algorithm 15 simulates depositionally realistic alignments that are consistent with the available radiocarbon age estimates and allows deriving uncertainty bands associated with the inferred alignment. Current composite chronologies from this region are reasonably consistent with our age model during the Holocene and the latter part of deglaciation. However, prior to ~14 kyr BP they yield too old age estimates with offsets that linearly increase up to ~40 kyr near the onset of Marine Isotope Stage (MIS) 2. -
Features of the Natural Environment and Modern Economy
Japan – features of the natural environment and modern economy Japan – features of the natural environment and modern economy Lesson plan (Polish) Lesson plan (English) Japan – features of the natural environment and modern economy Link to the lesson Before you start you should know that on Earth, in places where there is contact between lithospheric plates, there are seismic phenomena and active volcanoes; what the consequences of earthquakes can be and the destruction caused by undersea volcanic eruptions; which types of climate occur in Asia; that socio‐cultural factors play a vital role in the development of a country and its institutions. You will learn to determine the location of the Japanese archipelago and read the names of the largest of its islands; to identify the natural threats occuring in the area of East Asia which shape the natural environment of the Japanese archipelago; to name the ways people adapt to the natural threats (earthquakes, typhoons and tsunamis) in Japan; to identify the importance of social and cultural factors in the creation of Japan's modern economy. Nagranie dostępne na portalu epodreczniki.pl nagranie abstraktu Task 1 Think, and write your conclusions. What influences Japan's variations in climate? Japan's natural environment – threats and limitaons to selement and economic development The Japanese archipelago stretches in the shape of an arch with a length of approximately 2.5 km along the East coast of Asia, from the North‐East to the South‐West. Its main part is made up of 4 large islands – Hokkaido, Honsiu, Kiusiu and Sikoku – separated from Asia by the Sea of Japan, and from the West, surrounded by the open waters of the Pacific Ocean. -
Russia and the Arctic: the New Great Game 1 Dr Mark a Smith
Advanced Research and Assessment Group Russi an Series 07/26 Defence Academy of the United Kingdom The Last Dash North Dr Mark A Smith & Keir Giles Contents Russia and the Arctic: The New Great Game 1 Dr Mark A Smith Looking North 10 Keir Giles Key Points * The belief that the North Pole region could contain large quantities of oil and gas is one of the major forces driving Russian policy. The North Pole expedition of July-August 2007 is laying the ground for submitting a claim to the UN Commission on the Limits of the Continental Shelf that the Lomonosov Ridge belongs to Russia. * Russia’s claims will be challenged by Canada, the USA and Denmark. The Arctic region is likely to become a region of geopolitical competition later in the 21st century as the ice cap melts. * There is a widespread view in Russia that its claim to Arctic territory is not speculative, but rightful compensation for territorial losses in Europe. * Any foreign interest in the area, government, commercial or environmental, is seen as hostile intent. * Armed action by NATO to contest Russia’s Arctic claims is discussed as a serious possibility. * Reports of the death of the Russian North are greatly exaggerated, as they take no account of commercial rebirth based on the oil industry. * Russia has a well-developed commercial and transport infrastructure to take advantage of opportunities offered by the retreating icecap, in contrast to other littoral states. * Naval re-armament and increased military activity mean the same applies to capacity for military action. This map has been supplied courtesy of the University of Texas Libraries, The Univeristy of Texas at Austin.