DOCSLIB.ORG

Sediment Discharge Variability in Arctic Rivers: Implications for a Warmer Future

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Sediment Discharge Variability in Arctic Rivers: Implications for a Warmer Future Sediment discharge variability in Arctic rivers: implications for a warmer future James P. M. Syvitski A new model for predicting the sediment ß ux in ungauged river basins is applied to 46 Arctic to sub-Arctic rivers. The model predicts the pre- anthropogenic ß ux of sediment to within a factor of 2, across four orders of magnitude in basin area and run-off. The model explains for the Þ rst time why Arctic rivers carry so little sediment when compared at the global scale. Sensitive to drainage basin temperature, the model is used to examine the impact of a climate warming scenario on the loads of high latitude rivers. As the Arctic warms, rivers will carry increased sediment loads, similar to more temperate rivers. For every 2 °C warming, the model predicts a 22 % increase in the ß ux of sediment carried by rivers. For every 20 % increase in water discharge there will be a 10 % increase in sediment load. The model also aids the interpretation of palaeoclimate records obtained from Arctic continental margins. J. P. M. Syvitski, Institute of Arctic and Alpine Research, University of Colorado, 1560 30th St., Boulder, CO 80309-0450, USA. Compared to temperate and tropical rivers, the A new (2001) multi-agency SEARCH report sediment load discharged by Arctic rivers is (http://psc.apl.washington.edu/search/) warns: “it relatively low (Fig. 1a) in spite of large un con- is alarmingly clear that a complex suite of signif- solidated sedimentary deposits located through- i cant, interrelated atmospheric, oceanic and ter- out the Arctic, particularly in regions where restrial changes has occurred in the Arctic in the imprint of Pleistocene ice sheets remains recent decades.” These changes may provide a evident. This puzzle is at a time when Arctic large-scale manifestation of greenhouse warming: coast al erosion appears to be accelerating (Peck- 1) rapid penetration of the warmer Atlantic water ham et al. 2001). Siberian rivers are known to into the Arctic Ocean, concomitant with changes trans port very low sediment loads (Lopatin 1952; in surface water circulation and ice drift, and there- Alek seev & Lisitsyna 1974), while Canadian fore changes in atmospheric pressure patterns rivers like the Mackenzie are considered normal (Steele & Boyd 1998; Maslanik et al. 1999); (Milli man & Meade 1983). Bobrovitskaya et al. 2) warming of surface air temperature and (1996) suggested that the expanses of swamp increase in cloudiness (Serreze et al. 2000); and forest in the hinterlands of Siberian rivers 3) decrease in coastal ice extent thereby in creas- could account for their low load. Gordeev (2000) ing in storm fetch and surge, and mechanical– suggested that differences between Russian and thermal erosion of the coastal zone (e.g. Forbes & Canadian rivers are more a function of plate Syvitski 1995); and tectonics and the nature of the regional bedrock. 4) reduction in snow cover and increase in Recently Morehead et al. (in press) developed a ablation of glacier ice inducing changes in Arctic ß uvial model that suggested long-term sediment hydrology (Lemeshko 1992; Petersen et al. 1995; loads are partly dependent on the temperature of Van Blarcum et al. 1995; Dyurgerov & Meier a drainage basin: if the temperature is low, so is 1997; Kovalevsky 1998; Lammers et al. 2001). the relative load that a river can transport. The Arctic Ocean receives enough freshwater Syvitski 2002: Polar Research 21(2), 323–330 323 (a) (b) Fig. 1. (a) Sediment load (Qs) for sub-Arctic and Arctic rivers, predicted without a temperature correction but based on a global expression (Qs = βH3/2A1/2 see Syvitski & Morehead 1999) of the measured sediment load (Milliman & Syvitski 1992). Many rivers are predicted to transport more sediment than observed. (b) Rivers corrected for their cold basin temperatures (i.e. Qs = αH3/2A1/2ekT) fall on the global regression. discharge to determine its properties and circu- (Wilson 1973; Milliman & Syvitski 1992) and lation (Carmack 2000). Four of the world’s largest large-scale relief within it (Pinet & Souriau 1988; 15 rivers drain into the Arctic Ocean (Ob, Yenisei, Milliman & Syvitski 1992; Harrison 1994). Other Lena, Mackenzie); two others (Amur, Yukon) inß uences scale with one of these two parameters. drain into the North PaciÞ c. Draining signiÞ cant For example, local relief (Ahnert 1970; Jansen & tracts of permafrost terrain, their hydrology is Painter 1974) is correlative with large-scale relief dominated by the melt of seasonal snowfall. (Summer Þ eld & Hulton 1994), and ice cover Extreme events often control the land–sea ß ux and ice-melt scales with solar radiation and of material in the circum-Arctic (Lisitsyna relief (Andrews & Syvitski 1994). Precipitation 1974). Large Arctic rivers can discharge 90 % of intensity is captured in part through basin relief their sediment load in a month or less (Bobrovit- (Fournier 1960; Jansen & Painter 1974; Hay skaya et al. 1996, 1997). Other comparably sized et al. 1987). Run-off is correlative with basin temperate or tropical rivers lack this type of area (Walling 1987; Milliman & Syvitski 1992; dynamic response (Wang et al. 1998). Mulder & Syvitski 1996): in our Arctic river data A warming of between 4 °C and 6 °C is pre- (Table 1), average discharge Q, scales with basin dicted for the central Arctic by the middle of area A (Q = 0.93A0.82 at R2 = 0.892; Fig. 2). the 21st century (×2 CO2 scenario; Manabe et al. Vegetation scales with both regional tem- 1991; Lewis et al. 2001). Sediment ß ux by high perature and precipitation and can inß uence latitude rivers is expected to increase (Syvitski on a river’s sediment load (Douglas 1967). The & Andrews 1994). Unfortunately at this critical rock and soil type within a basin also provides time of change, there has been a rapid decrease local variability to sediment delivery (Pinet & in the monitoring of pan-Arctic rivers, both for Souriau 1988; Milliman & Syvitski 1992; In man their water discharge (Shiklomanov et al. 2002) & Jenkins 1999). Lakes may Þ lter out a river’s and for their sediment load (Syvitski et al. 2000). sediment load (Vörösmarty et al. 2001); Arctic This paper examines the ß ux of sediment from terrain has a high density of lakes (Milli man Arctic and sub-Arctic rivers, and applies a model 1980). Basin temperature inß uences the sediment for estimating the sediment ß ux for ungauged load carried by rivers through control of the rivers given a climate warming scenario. number of soil-forming frost cycles and (frozen) ground conditions (Syvitski & More head 1999). Drainage basin properties affecting sediment load High latitude drainage basin data A variety of non-anthropogenic factors inß uence Table 1 provides data on the drainage properties the “natural” sediment load of a river, but the of 46 Arctic and sub-Arctic rivers that represent signiÞ cant factors are the size of a drainage basin the spectrum of northern environments. The data 324 Sediment discharge variability in Arctic rivers: implications for a warmer future set includes 28 rivers that together account for Þ ve orders of magnitude, from 90 km2 (South) 70 % of the land surface draining into the Arctic to 2 929 000 km2 (Ob). Relief H, is measured Ocean (Prowse & Flegg 2000), 13 rivers that between the elevation of the gauging station drain into the North Atlantic (including Hudson and the highest point of land, and varies from Bay), and 7 rivers that drain into the North PaciÞ c 75 m (Kalkkinen, Finland) to 6094 m (Yukon, through coastal mountain ranges. The rivers Alaska). Long-term sediment discharge varies are located in Russia, Canada or the US, with from 0.1 kg/s (Kalkkinen) to 2580 kg/s (Liard). one Finnish river to represent coastal plain sub- Some rivers have very low turbidity levels (e.g. Arctic drainage. Drainage area A varies across 0.01 kg/m3: Attawapiskat), while others are Table 1. Drainage properties of 46 Arctic and sub-Arctic rivers derived from the databases of Binda et al (1986), Milliman & Syvitski (1992, with revisions from Bobrovitskaya et al. 1996, 1997), Gordeev (2000) and Syvitski et al. (2000). River Receiving Areaa H b Mean T c Qd Cse Qsf Pred. Qsg T-PQsh Q-PQsi Pred. Obs. Pσ-cl ocean (km2) (m) (°C) (m3/s) (kg/m3) (kg/s) (kg/s) (kg/s) (kg/s) C j (-) C k (-) (-) South (Can) Atl. 90 1025 -13 1 1.350 2 6 2 1 1.87 0.17 Middle (Can) Atl. 110 865 -13 2 1.100 2 5 1 1 1.82 0.17 North (Can) Atl. 190 1060 -13 4 1.160 4 10 3 2 1.93 0.17 Ekalugad Fjord (Can) Atl. 380 1060 -13 7 1.180 8 13 4 3 1.98 0.17 St. Jean (Can) Atl. 5600 990 1 1100 0.010 8 47 16 75 2.13 0.19 Murray (Can) Arct. 5620 1686 -3 452 0.192 87 104 77 174 2.31 2.70 0.18 Homathko (Can) Pac. 5700 3994 2 253 0.540 136 381 89 527 2.79 2.60 0.17 Odei R (Can) Atl. 6130 222 0 67 0.075 5 5 5 4 1.67 1.60 0.17 Klinaklini (Can) Pac. 6500 3800 2 330 0.480 158 378 92 566 2.77 0.18 N Saskatchewan (Can) Atl. 11000 2212 -4 156 0.891 139 218 146 128 2.49 2.40 0.17 Romaine (Can) Atl. 14000 650 0 5 39 17 2.03 Arctic Red (Can) Arct. 18600 2452 -4 752 0.192 452 331 222 237 2.60 2.80 0.18 Stikine (Can) Pac.
Load more

Recommended publications
  • Ob' River Discharge from TOPEX/Poseidon Satellite Altimetry
    Ob’ river discharge from TOPEX/Poseidon satellite altimetry (1992–2002) A. Kouraev, E. A. Zakharova, O. Samain, N. Mognard-Campbell, A. Cazenave To cite this version: A. Kouraev, E. A. Zakharova, O. Samain, N. Mognard-Campbell, A. Cazenave. Ob’ river discharge from TOPEX/Poseidon satellite altimetry (1992–2002). Remote Sensing of Environment, Elsevier, 2004, 93 (1-2), pp.238-245. 10.1016/j.rse.2004.07.007. hal-00280276 HAL Id: hal-00280276 https://hal.archives-ouvertes.fr/hal-00280276 Submitted on 6 Apr 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Distributed under a Creative Commons Attribution| 4.0 International License Ob’ river discharge from TOPEX/Poseidon satellite altimetry (1992–2002) Alexei V. Kouraeva,b,*, Elena A. Zakharovab, Olivier Samainc, Nelly M. Mognarda, Anny Cazenavea aLaboratoire d’Etudes en Ge´ophysique et Oce´anographie Spatiales (LEGOS), Toulouse, France bState Oceanography Institute, St. Petersburg Branch, St. Petersburg, Russia cMe´te´o-France, CNRM, Toulouse, France The paper discusses an application of the TOPEX/Poseidon (T/P) altimetry data to estimate the discharge of one of the largest Arctic rivers—the Ob’ river. We first discuss the methodology to select and retrieve the altimeter water levels during the various phases of the hydrological regime.
    [Show full text]
  • The Security of the Caspian Sea Region
    4. The Caspian Sea: threats to its biological resources and environmental security Igor Zonn I. Introduction The Caspian Sea is the world’s largest inland sea. Physiographically it is unique. It is the most productive body of water in the world1 and the only one that preserves the geno-fund of the sturgeon, the source of almost all the black caviar produced. About 10 million people live around the Caspian Sea and the occupations of many of them are connected with the sea, and first of all with fishing. By virtue of its oil and gas potential the Caspian has a place among the major world centres of hydrocarbon production. The rivers of the largest water catchment area in the world discharge into it from the industrial and production regions of the littoral states. This fact accounts for the periodic fluctuations of the sea level and for the nature and scale of pollution of the sea. As for the water body itself, there has always been a conflict between the use of its principal natural resources—biological resources (fishing of valuable fish species, first and foremost the sturgeon)—and the exploitation of hydrocarbons (the development of shelf and offshore oil and gas fields). This conflict has become especially acute since the breakup of the Soviet Union, as a result of which the legal status of the Caspian Sea changed, regulation of the exploitation of the sea’s resources has broken down, and the geopolitical interests of five different states conflict. These interests are those connected with military and political security, with shipping, with the exploitation of biological and mineral resources, and with environmental security.
    [Show full text]
  • Frontex · Western Balkans Annual Risk Analysis 2018 Table of Contents
    Western Balkans Annual Risk Analysis 2018 Western Balkans Annual Risk Analysis 2018 Plac Europejski 6, 00-844 Warsaw, Poland T +48 22 205 95 00 F +48 22 205 95 01 [email protected] www.frontex.europa.eu Warsaw, April 2018 Risk Analysis Unit Frontex reference number: 10807/2018 PDF TT-AD-18-001-EN-N ISBN 978-92-9471-192-2 doi:10.2819/41268 Cover photo: Romanian border police All rights reserved. DISCLAIMERS This is a Frontex staff-working document. Its contents do not imply the expression of any opinion whatso- ever on the part of Frontex concerning the legal status of any country, territory or city or its authorities, or concerning the delimitation of its frontiers or boundaries. All maps, charts, figures and data included in this presentation are the sole property of Frontex and any unauthorised use is prohibited. Frontex disclaims any liability with respect to the boundaries, names and designations used on the map. Throughout this report, all references to Kosovo are marked with an asterisk (*) to indicate that this des- ignation is without prejudice to positions on status, and is in line with UNSCR 1244 and the ICJ Opinion on the Kosovo declaration of independence. ACKNOWLEDGMENTS The Western Balkans Annual Risk Analysis 2018 has been prepared by the Frontex Risk Analysis Unit. During the course of developing this product, many colleagues at Frontex and outside contributed to it and their assis- tance is hereby acknowledged with gratitude. 2 of 52 Frontex · Western Balkans Annual Risk Analysis 2018 Table of Contents Executive summary #5 1.
    [Show full text]
  • Turkey's Role in the Western Balkans
    SWP Research Paper Stiftung Wissenschaft und Politik German Institute for International and Security Affairs Alida Vračić Turkey’s Role in the Western Balkans RP 11 December 2016 Berlin All rights reserved. © Stiftung Wissenschaft und Politik, 2016 SWP Research Papers are peer reviewed by senior researchers and the execu- tive board of the Institute. They reflect the views of the author(s). SWP Stiftung Wissenschaft und Politik German Institute for International and Security Affairs Ludwigkirchplatz 3­4 10719 Berlin Germany Phone +49 30 880 07-0 Fax +49 30 880 07-200 www.swp-berlin.org [email protected] ISSN 1863-1053 This research and its publi- cation have been enabled by the generous support of Stiftung Mercator, Essen. Table of Contents 5 Issues and Conclusions 7 Turkey’s Comeback in the Balkans 12 Turkey’s Economy and Non-state Actors in the Western Balkans 15 Turkish Military in the Balkans 18 Countries of Particular Interest to Turkey 18 Bosnia and Herzegovina 22 Kosovo 24 Macedonia 27 Can Old Animosities Die? Serbia-Turkey Relations 30 Turkey’s Activism as Seen from the Balkans 32 Western Balkans – EU’s Forgotten Post? 33 Outlook 34 Abbreviations Alida Vračić is IPC-Stiftung Mercator Fellow 2015/2016 at SWP Issues and Conclusions Turkey’s Role in the Western Balkans For the past two decades, Turkey has been rediscover- ing the Balkans. The end of the Cold War and the dis- solution of the former Yugoslavia in the 1990s and the subsequent violence were decisive points in Turkish foreign policy. New openings toward southeast Europe and the creation of new states greatly transformed the foreign policy strategies of Turkey, which was aiming for far-reaching political impact.
    [Show full text]
  • Salt Intrusions in Siberian River Estuaries
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Electronic Publication Information Center 27 Harmsetal. Salt intrusions in Siberian river estuaries: Observations and model experimentsinObandYenisei I.H.Harms1*,U.Hübner1,J.O.Backhaus1,M.Kulakov2,V.Stanovoy2,O.V.Stepanets3,L.A. Kodina3,R.Schlitzer4. 1InstituteforOceanography,UniversityHamburg,Germany 2ArcticandAntarcticResearchInstitute(AARI),St.Petersburg,Russia 3VernadskyInstituteofGeochemistryandAnalyticalChemistry,RussianAcademyofSciences,ul.Kosygina19, Moscow,119991,Russia 4AlfredWegenerInstituteforPolarandMarineResearch,Columbusstrasse2,27568Bremerhaven, Germany Abstract Observations in Siberian river estuaries show a very pronounced vertical stratification duringsummer.InparticularintheYeniseiEstuary,salinityprofilesarestronglyaffected,not onlybyfreshwaterrunoff,butalsobybottomfollowingsaltintrusionsthatpenetrateactively intotheestuary. Inordertostudytheestuarinevariabilityandtoinvestigatethephysicsbehindthesesalt intrusions, two different numerical circulation models are applied to the Kara Sea and the estuariesofObandYenisei.The3-D,baroclinicmodelsarebasedontherealistictopography, forcedwithwind,tidesandriverrunoff. Modelresultsfromsummerrevealageneralnorthwardflowofriverwateratthesurface out of the estuaries. Near the bottom, however, a south-westward transport of saline water from the Taymyr coast towards theestuariesprevails.Asaltintrusionoccursduringstrong runoffwhenthedirectionofthewind-inducedoffshoretransportisalignedwiththeaxisof
    [Show full text]
  • Russia Inflicting Crimes Against Humanity Upon the Crimean Tartars
    American University International Law Review Volume 36 Issue 2 Article 6 2021 Repeating History: Russia Inflicting Crimes Against Humanity Upon the Crimean Tartars Katerina Dee Follow this and additional works at: https://digitalcommons.wcl.american.edu/auilr Part of the International Humanitarian Law Commons, and the International Law Commons Recommended Citation Katerina Dee (2021) "Repeating History: Russia Inflicting Crimes Against Humanity Upon the Crimean Tartars," American University International Law Review: Vol. 36 : Iss. 2 , Article 6. Available at: https://digitalcommons.wcl.american.edu/auilr/vol36/iss2/6 This Comment or Note is brought to you for free and open access by the Washington College of Law Journals & Law Reviews at Digital Commons @ American University Washington College of Law. It has been accepted for inclusion in American University International Law Review by an authorized editor of Digital Commons @ American University Washington College of Law. For more information, please contact [email protected]. REPEATING HISTORY RUSSIA INFLICTING CRIMES AGAINST HUMANITY UPON THE CRIMEAN TATARS KATERINA DEE I. INTRODUCTION............................................................. II. BACKGROUND............................................................... A. TURMOIL IN CRIMEA AN OVERVIEW OF THE CRIMEAN TATARS’ HISTORY AND OF RUSSIA’S ACTIONS SINCE ............................................................................. The Crimean Tatars A History of Displacement and Marginalization.....................................................
    [Show full text]
  • An Assessment of the Flux of Radionuclide Contamination Through the Ob and Yenisei Rivers and Estuaries to the Kara Sea
    NO9700007 An Assessment of the Flux of Radionuclide Contamination Through the Ob and Yenisei Rivers and Estuaries to the Kara Sea THERESA PALUSZKIEWICZ1, LYLE F. HIBLER1, MARSHALL C. RICHMOND2, DON J. BRADLEY2 ''Pacific Northwest Laboratory, Battelle Marine Sciences Laboratory, 1529 West Sequim Bay Road, Sequim, WA 98382, USA . 2Pacific Northwest Laboratory, P.O. Box 999, Richland, WA 99352, USA. Introduction Extensive radioactive contamination (about 63,000 PBq) has been discharged to the environment of the West Siberian Basin. The former Soviet Union (FSU) nuclear program has been operating for the last 50 years; most of its facilities are located in the West Siberian Basin. These nuclear facilities include three sites for reprocessing spent fuel from the FSU's production reactors: Mayak, Tomsk-7, and Krasnoyarsk-26 (Fig. 1). These are believed to be responsible for the majority of the radioactive contamination that is in the major river systems, the Ob and Yenisei, which feed into the Arctic Ocean through the Kara Sea. Extensive radioactive contamination has been reported in surface water reservoirs, and large amounts of radioactive contamination have been discharged to injection sites that are adjacent to tributaries of the Ob and Yenisei Rivers. A massive release of radionuclide contaminants could result if floods, reservoir failures, or containment failures were to occur (Foley, 1991; Bradley, 1991, 1992a, 1992b; Bradley and Schneider, 1990). The Ob River system consists of the contaminant release sites (FSU nuclear defense sites on land), the terrestrial, ground, and surface waters that link the contaminant release sites to the rivers, the Ob River, its tributaries, the estuary, and the confluence region where the estuaries of the Ob and Yenisei mix and flow into the Kara Sea (Fig.
    [Show full text]
  • BUSINESS, CORRUPTION and CRIME in the WESTERN BALKANS: the Impact of Bribery and Other Crime on Private Enterprise 2013
    BUSINESS, CORRUPTION AND CRIME IN THE WESTERN BALKANS: BUSINESS, CORRUPTION AND CRIME The impact of bribery and other crime on private enterprise IN THE WESTERN BALKANS: The impact of bribery and 2013 other crime on private enterprise 2013 With funding from the European Union UNITED NATIONS OFFICE ON DRUGS AND CRIME Vienna BUSINESS, CORRUPTION AND CRIME IN THE WESTERN BALKANS: The impact of bribery and other crime on private enterprise 2013 Copyright 2013 © United Nations Office on Drugs and Crime (UNODC) Acknowledgements This report was prepared by UNODC Statistics and Surveys Section (SASS). Research coordination and report preparation: Enrico Bisogno (SASS) Michael Jandl (SASS) Felix Reiterer (SASS) Field research: Albania: Olsida Capo, Elsa Dhuli, Ines Nurja (Institute of Statistics of Albania) Bosnia and Herzegovina: Dino Djipa, Salminka Fazlic (Prism Research) Croatia: Jelena Budak, Edo Rajh (Institute of Economics, Zagreb) Kosovo: Muhamet Kastrati, Bashkim Bellaqa, Isa Krasniqi, Ibrahim Rrustemi, Sanije Ismajli (Kosovo Agency of Statistics) Montenegro: Gordana Radojević, Snezana Remikovic, Biljana Sekulovic (Statistical Office of Montenegro) Serbia: Jelena Budimir, Tijana Comic (Statistical Office of the Republic of Serbia) The former Yugoslav Republic of Macedonia: Blagica Novkovska, Helena Papazoska (State Statistical Office) Project Associates: Regional Anti-Corruption Initiative for South Eastern Europe (RAI), Transcrime Design and layout: Suzanne Kunnen, Kristina Kuttnig (Research and Trend Analysis Branch, RAB) Editing: Jonathan Gibbons Supervision: Sandeep Chawla (Director, Division of Policy Analysis and Public Affairs) and Angela Me (Chief, RAB) Appreciation and gratitude go to the Bosnia and Herzegovina Agency for Statistics (BHAS) for the techni- cal support they provided in compiling the sampling frame for Bosnia and Herzegovina.
    [Show full text]
  • Separating Individual Contributions of Major Siberian Rivers in The
    www.nature.com/scientificreports OPEN Separating individual contributions of major Siberian rivers in the Transpolar Drift of the Arctic Ocean Ronja Pafrath1*, Georgi Laukert2, Dorothea Bauch2,3, Michiel Rutgers van der Loef4 & Katharina Pahnke1 The Siberian rivers supply large amounts of freshwater and terrestrial derived material to the Arctic Ocean. Although riverine freshwater and constituents have been identifed in the central Arctic Ocean, the individual contributions of the Siberian rivers to and their spatiotemporal distributions in the Transpolar Drift (TPD), the major wind-driven current in the Eurasian sector of the Arctic Ocean, are unknown. Determining the infuence of individual Siberian rivers downstream the TPD, however, is critical to forecast responses in polar and sub-polar hydrography and biogeochemistry to the anticipated individual changes in river discharge and freshwater composition. Here, we identify the contributions from the largest Siberian river systems, the Lena and Yenisei/Ob, in the TPD using dissolved neodymium isotopes and rare earth element concentrations. We further demonstrate their vertical and lateral separation that is likely due to distinct temporal emplacements of Lena and Yenisei/Ob waters in the TPD as well as prior mixing of Yenisei/Ob water with ambient waters. Te Arctic Ocean is unique with respect to its high freshwater input from the Siberian and North American rivers (11% of global river discharge), which not only infuences circulation, stratifcation and deep water formation in the high northern latitudes1 but also afects water column biogeochemistry and ecosystem functioning through addition of large amounts of river-borne macro- and micronutrients, as well as lithogenic elements to the open ocean2–11.
    [Show full text]
  • COLOR and DISCOVER a Journey Through Central America's Past
    Coloring Book Cover_Rev1_Layout 1 6/13/13 3:11 PM Page 1 COLOR AND DISCOVER A Journey through Central America’s Past Dear parents, Thank you for visiting the Smithsonian! The exhibition Cerámica de los Ancestros: Central America’s Past Revealed, on view at the National Museum of the American Indian, is a window into the lives of the people who once lived in the lands we now call Guatemala, Belize, Honduras, El Salvador, Nicaragua, Costa, Rica, and Panama. The exhibition uses objects made of clay—as well as several objects of gold, stone, shell and jade—to explore themes such as everyday life, social identity, belief systems, wealth, and the animal world. These objects convey information about the past and reveal important aspects of life in ancient Central America. This activity guide and coloring book introduces your family to a wonderful collection of Central American ceramic art. We encourage you to read and engage in the questions, coloring, and other enrichment activities with your children. In addition to this guide there are other online resources, including an accompanying simulated “3-D Base Camp” for elementary, middle, and high school students. This simulated adventure can be downloaded by visiting http://latino.si.edu and click on the Exhibitions tab. This simulated environment allows players to immerse themselves into a virtual landscape of Central America, and to learn about archaeology and anthropology as part of a field expedition team. As part of this team, you will discover more about the Central American collections of the National Museum of the American Indian.
    [Show full text]
  • Geology: Control on Sediment and Organic Carbon Delivery to the Arctic Ocean Revealed with Space-Borne Synthetic Aperture Radar;
    Control on sediment and organic carbon delivery to the Arctic Ocean revealed with space-borne synthetic aperture radar: Ob’ River, Siberia Laurence C. Smith Department of Geog raphy, University of California, Los Ang eles, Box 951524, Bunche Hall, Los Ang eles, California 90095-1524 Douglas E. Alsdorf Department of Geolog ical Sciences, Cornell University, Snee Hall, Ithaca, New York 14853-1504 ABSTRACT An important control on river biogeochemistry and sediment load is the process of water ex- change between primary channels and the flood plain, particularly in low-relief areas containing lakes, ephemeral channels, and other aquatic ecosystems. Flood-plain exchange may be a domi- nant process on the lowland rivers of Arctic Russia, which are among the world’s largest in water discharge yet are strikingly deficient in their delivery of sediment to the Arctic shelf. Temporal synthetic aperture radar (SAR) amplitude and interferometric images of the Ob’ River, Siberia, reveal a time-varying limnological network controlling water, sediment, and nutrient exchange between flood-plain wetlands and the main channel. The amount of hydrologic exchange decreases by one order of magnitude from June to September, enhancing sedimentation over as much as 90% of the flood plain and enriching channel waters with colloidal organic carbon. This observation, combined with Russian field measurements of water discharge and sediment load, indicates that a major sediment sink on the lower Ob’ flood plain may be responsible for the low amount of sediment delivery
    [Show full text]
  • Daedaleopsis Genus in Siberia and the Far East of Russia
    Proceedings BDI-2020, 17-26 doi: 10.3897/ap.2.e58134 III Russian National Conference “Information Technology in Biodiversity Research” Daedaleopsis Genus in Siberia and the Far East of Russia Viktoria D. Vladykina*(a), Victor A. Mukhin (b), Susanna M. Badalyan (c) (a) ORCID: 0000-0002-4877-2259, Department of Biodiversity and Bioecology, Institute of Natural Sciences and Mathematics, Ural Federal University named after the first President of Russia B.N. Yeltsin, 19 Mira Street, 620003 Ekaterinburg, Russia (b) ORCID: 0000-0003-4509-4699, Department of Biodiversity and Bioecology, Institute of Natural Sciences and Mathematics, Ural Federal University named after the first President of Russia B.N. Yeltsin, 19 Mira Street, 620003 Ekaterinburg, Russia, Institute of Plant and Animal Ecology, Ural Branch of Russian Academy of Sciences, 202, 8 Marta Street, 620144, Ekaterinburg, Russia (c) ORCID: 0000-0001-9273-5730, Laboratory of Fungal Biology and Biotechnology, Institute of Pharmacy, Yerevan State University, 1 A. Manoogian Street, 0025 Yerevan, Armenia Abstract The current article discusses the findings of the study of biodiversity, distribution, and ecology of Daedaleopsis species in the Siberia and Russian Far East are presented. In this part of Eurasia, the genus Daedaleopsis is represented by 3 species, D. confragosa, D. tricolor and D. septentrionalis. They are distributed in all regions of Siberia and the Russian Far East (the most common are D. confragosa and D. tricolor) and contribute to the decomposition of woody debris of several deciduous (Acer, Alnus, Betula, Carpinus, Chosenia, Crataegus Quercus, Padus, Populus, Salix, Sorbus, Tilia) and rarely coniferous (Abies) trees. Each species has its own pattern of geographical and substrate distribution.
    [Show full text]