DOCSLIB.ORG

Low-Level Easterly Winds Blowing Through the Tsugaru Strait, Japan

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Low-Level Easterly Winds Blowing Through the Tsugaru Strait, Japan JUNE 2012 S H I M A D A E T A L . 1779 Low-Level Easterly Winds Blowing through the Tsugaru Strait, Japan. Part II: Numerical Simulation of the Event on 5–10 June 2003 TERUHISA SHIMADA Ocean Environment Group, Center for Atmospheric and Oceanic Studies, Graduate School of Science, Tohoku University, Sendai, Japan MASAHIRO SAWADA AND WEIMING SHA Atmospheric Science Laboratory, Graduate School of Science, Tohoku University, Sendai, Japan HIROSHI KAWAMURA Ocean Environment Group, Center for Atmospheric and Oceanic Studies, Graduate School of Science, Tohoku University, Sendai, Japan (Manuscript received 5 February 2011, in final form 3 January 2012) ABSTRACT This paper investigates the structures of and diurnal variations in low-level easterly winds blowing through the Tsugaru Strait and Mutsu Bay on 5–10 June 2003 using a numerical weather prediction model. Cool air that accompanies prevailing easterly winds owing to the persistence of the Okhotsk high intrudes into the strait and the bay below 500 m during the nighttime and retreats during the daytime. This cool-air intrusion and retreat induce diurnal variations in the winds in the east inlet of the strait, in Mutsu Bay, and in the west exit of the strait. In the east inlet, a daytime increase in air temperature within the strait produces a large air temperature difference with the inflowing cool air, and the resulting pressure gradient force accelerates the winds. The cool air flowing into Mutsu Bay is heated over land before entering the bay during the daytime. The resulting changes in cool-air depth and in pressure gradient force strengthen the daytime winds. In the west exit, local pressure gradient force perturbations are induced by the air temperature difference between warm air over the Japan Sea and cool air within the strait, and by variations in the depth of low-level cool air. The accelerated winds in the west exit extend southwestward in close to geostrophic balance during the daytime and undergo a slight anticyclonic rotation to westerly during the nighttime owing to the dominance of the Coriolis effect. 1. Introduction months, particularly in June–July (Fig. 1 of Part I). These winds occur to the west of the east–west passage that Strong winds can develop in the exit region of a terres- connects the western North Pacific and the Japan Sea and trial gap when an along-gap pressure gradient is created consists of the Tsugaru Strait, Mutsu Bay, and circumjacent mostly in conjunction with cold-air surges (e.g., Overland low-level terrestrial gaps (Fig. 1); these winds are asso- and Walter 1981; Steenburgh et al. 1998; Chelton et al. ciated with cool maritime air accompanying the easterly 2000; Colle and Mass 2000; Sharp and Mass 2004). A wind over the Pacific. This easterly wind, commonly known companion paper to this study (Shimada et al. 2010, as Yamase in Japan (e.g., Takai et al. 2006), intermittently hereafter Part I) has focused on such strong winds that blows toward northern Japan from the Okhotsk high dur- frequently occur in northern Japan during the summer ing the summer months. Using observational and reanaly- sis data, Part I first presented the structures and evolutions of the easterly surface winds within and adjacent to the Corresponding author address: Teruhisa Shimada, Ocean Envi- TsugaruStraitandMutsuBay. ronment Group, Center for Atmospheric and Oceanic Studies, Graduate School of Science, Tohoku University, Aramaki Aza The two main results derived from Part I are as fol- Aoba 6-3, Aoba-ku, Sendai, Miyagi 980-8578, Japan. lows: 1) the pressure gradient force along the Tsugaru E-mail: [email protected] Strait predominantly induces the easterly strong winds DOI: 10.1175/MWR-D-11-00035.1 Ó 2012 American Meteorological Society Unauthenticated | Downloaded 09/30/21 12:36 PM UTC 1780 MONTHLY WEATHER REVIEW VOLUME 140 cycles of the local wind accelerations. As possible cau- ses, Part I has suggested diurnally varying cool-air in- trusion into the strait and the bay from the east, and complex distribution of land and sea with differential heating and cooling on the basis of Kawai et al. (2006). To address these challenges, analyses of numerical sim- ulation data are indispensable. Therefore, this study investigates the diurnal varia- tions in the low-level easterly winds within and adjacent to the Tsugaru Strait and Mutsu Bay using a numerical weather prediction model. We focus on a sustained east- erly wind event occurring on 5–10 June 2003, described in previous studies (Shimada and Kawamura 2007, 2009; Part I). In particular, we compare the locally strong winds in the east inlet of the strait, in Mutsu Bay, and in the west FIG. 1. Study area and geographical names referred to in this exit of the strait, and we examine the differences and paper. Gray contours show monthly mean SST in June 2003 at every 18C. The framed rectangle indicates the inner domain of the similarities in wind acceleration and diurnal variation. model simulation. The color scale indicates terrain elevation. The This case study offers a comprehensive vision of sur- solid circles and triangle denote weather observation stations face winds under conditions frequently occurring dur- [Hakodate (HK) and Fukaura (FK)] and a buoy in Mutsu Bay, ing the summer in this study area, which leads to better respectively. The square indicates the location for which wind understanding of regional weather and climate. More speeds from the simulated data and the SeaWinds observations are compared. importantly, this study is the first to investigate diurnally varying gap winds; previous studies have focused on a one-time event of gap winds. in the west of the strait. The maritime cool air accom- We give brief descriptions of our meteorological model panying the easterly winds is blocked by the central simulation in the following section. In section 3, we spine of the mountains of northern Japan and is dammed present horizontal and vertical structures of the wind and on the east side (Fig. 1 of Part I). The resulting east–west the cool air within and adjacent to the Tsugaru Strait and air temperature differences create an along-strait sea Mutsu Bay, and we explore causes of the diurnal varia- level pressure (SLP) gradient on a regional to synoptic tions in the low-level winds in section 4. Section 5 is de- scale (Fig. 10 of Part I). 2) The strong winds in the west voted to the summary and discussion. In this study, we use of the strait vary diurnally under sustained upstream Japan standard time (JST, UTC 1 9 h) for descriptions winds from the east. Stronger (weaker) and easterly hereafter because this study deals with diurnal variation. (east northeasterly) winds are observed during the night- time (daytime), corresponding to the cool-air intrusion from the east (retreat from the west; Figs. 4 and 11 of 2. Model simulations Part I). Meanwhile, the easterly winds over the land and a. Model description in Mutsu Bay are stronger (weaker) during the daytime (nighttime). Thus, the large-scale pressure gradient force The model simulation was designed with the fifth- responsible for the easterly strong winds to the west of the generation Pennsylvania State University–National Cen- strait is modified by the diurnal cycle of thermal forcing. ter for Atmospheric Research (PSU–NCAR) Mesoscale At the same time, Part I has presented the following Model (MM5; Grell et al. 1995). According to studies that challenges for further understanding of the low-level simulate and validate winds over the ocean (e.g., Song winds blowing through the Tsugaru Strait and Mutsu et al. 2004), we chose the following physical options for Bay. 1) Mechanisms of local wind accelerations within model simulation: the cumulus parameterization of Grell the strait and the bay remain unresolved issues. Al- et al. (1995), the simple ice scheme of Dudhia (1993), a though there is evidence that the local wind accelera- cloud radiation scheme accounting for longwave and tions occur in the east inlet of the strait (around 41.68N, shortwave radiative transfers in cloudy and clear air 140.88E) and in Mutsu Bay (Yamaguchi and Kawamura (Dudhia 1989), a five-layer soil temperature model with 2005; Part I), detailed investigations into the causes of a fixed substrate (Dudhia 1996), and the National Cen- the wind accelerations need to be conducted. The mech- ters for Environmental Prediction (NCEP) Medium- anism of the wind acceleration in the west of the strait also Range Forecast scheme for planetary boundary layer merits further study. 2) We need to look into the diurnal processes (Hong and Pan 1996). Unauthenticated | Downloaded 09/30/21 12:36 PM UTC JUNE 2012 S H I M A D A E T A L . 1781 wind event. The simulation underestimates the SLP difference by an average of 0.95 hPa. However, the variation in the simulated SLP difference is generally consistent with that of the observed, and diurnal varia- tion in the SLP difference is represented in the simula- tion. We next compare the surface wind fields shown in Fig. 3 with the observed data (Figs. 4 and 5 of Part I). FIG. 2. Hourly SLP differences between the weather observation The simulation underestimates the maximum wind station data (gray) and the simulated data (black) for the locations speeds exiting from the west of the strait. The simulated of stations HK and FK. Because station FK is located outside the 21 inner domain, data from the outer domain are used here. wind speed at the location indicated in Fig. 1 is 1.38 m s less than the SeaWinds scatterometer observations dur- ing the entire simulation period on an average.
Load more

Recommended publications
  • PICES Sci. Rep. No. 2, 1995
    TABLE OF CONTENTS Page FOREWORD vii Part 1. GENERAL INTRODUCTION AND RECOMMENDATIONS 1.0 RECOMMENDATIONS FOR INTERNATIONAL COOPERATION IN THE OKHOTSK SEA AND KURIL REGION 3 1.1 Okhotsk Sea water mass modification 3 1.1.1Dense shelf water formation in the northwestern Okhotsk Sea 3 1.1.2Soya Current study 4 1.1.3East Sakhalin Current and anticyclonic Kuril Basin flow 4 1.1.4West Kamchatka Current 5 1.1.5Tides and sea level in the Okhotsk Sea 5 1.2 Influence of Okhotsk Sea waters on the subarctic Pacific and Oyashio 6 1.2.1Kuril Island strait transports (Bussol', Kruzenshtern and shallower straits) 6 1.2.2Kuril region currents: the East Kamchatka Current, the Oyashio and large eddies 7 1.2.3NPIW transport and formation rate in the Mixed Water Region 7 1.3 Sea ice analysis and forecasting 8 2.0 PHYSICAL OCEANOGRAPHIC OBSERVATIONS 9 2.1 Hydrographic observations (bottle and CTD) 9 2.2 Direct current observations in the Okhotsk and Kuril region 11 2.3 Sea level measurements 12 2.4 Sea ice observations 12 2.5 Satellite observations 12 Part 2. REVIEW OF OCEANOGRAPHY OF THE OKHOTSK SEA AND OYASHIO REGION 15 1.0 GEOGRAPHY AND PECULIARITIES OF THE OKHOTSK SEA 16 2.0 SEA ICE IN THE OKHOTSK SEA 17 2.1 Sea ice observations in the Okhotsk Sea 17 2.2 Ease of ice formation in the Okhotsk Sea 17 2.3 Seasonal and interannual variations of sea ice extent 19 2.3.1Gross features of the seasonal variation in the Okhotsk Sea 19 2.3.2Sea ice thickness 19 2.3.3Polynyas and open water 19 2.3.4Interannual variability 20 2.4 Sea ice off the coast of Hokkaido 21
    [Show full text]
  • The Kuroshio Extension: a Leading Mechanism for the Seasonal Sea-Level Variability Along the West
    1 The Kuroshio Extension: A Leading Mechanism for the Seasonal Sea-level Variability along the West 2 Coast of Japan 3 4 Chao Ma1, 2, 3, Jiayan Yang3, Dexing Wu2, Xiaopei Lin2 5 6 1. College of Physical and Environmental Oceanography 7 Ocean University of China 8 Qingdao 266100, China 9 2. Physical Oceanography Laboratory 10 Ocean University of China 11 Qingdao 266100, China 12 3. Department of Physical Oceanography 13 Woods Hole Oceanographic Institution 14 Woods Hole, MA 02543, USA 15 16 Corresponding Author: Chao Ma ([email protected]) 17 Abstract 18 Sea level changes coherently along the two coasts of Japan on the seasonal time scale. AVISO 19 satellite altimetry data and OFES (OGCM for the Earth Simulator) results indicate that the variation 20 propagates clockwise from Japan's east coast through the Tsushima Strait into the Japan/East Sea (JES) 21 and then northward along the west coast. In this study, we hypothesize and test numerically that the sea 22 level variability along the west coast of Japan is remotely forced by the Kuroshio Extension (KE) off the 23 east coast. Topographic Rossby waves and boundary Kelvin waves facilitate the connection. Our 3-d 24 POM model when forced by observed wind stress reproduces well the seasonal changes in the vicinity 25 of JES. Two additional experiments were conducted to examine the relative roles of remote forcing and 26 local forcing. The sea level variability inside the JES was dramatically reduced when the Tsushima Strait 27 is blocked in one experiment. The removal of the local forcing, in another experiment, has little effect on 28 the JES variability.
    [Show full text]
  • Scouting, Signaling, and Gatekeeping: Chinese Naval
    U.S. NAVAL WAR COLLEGE CHINA MARITIME STUDIES Number 2 Scouting, Signaling, and Gatekeeping Chinese Naval Operations in Japanese Waters and the International Law Implications ISBN: 978-1-884733-60-4 Peter Dutton 9 781884 733604 Scouting, Signaling, and Gatekeeping Chinese Naval Operations in Japanese Waters and the International Law Implications Peter Dutton CHINA MARITIME STUDIES INSTITUTE U.S. NAVAL WAR COLLEGE NEWPORT, RHODE ISLAND www.usnwc.edu/cnws/cmsi/default.aspx Naval War College The China Maritime Studies are extended research projects Newport, Rhode Island that the editor, the Dean of Naval Warfare Studies, and the Center for Naval Warfare Studies President of the Naval War College consider of particular China Maritime Study No. 2 interest to policy makers, scholars, and analysts. February 2009 Correspondence concerning the China Maritime Studies may be addressed to the director of the China Maritime President, Naval War College Studies Institute, www.usnwc.edu/cnws/cmsi/default.aspx. Rear Admiral James P. Wisecup, U.S. Navy To request additional copies or subscription consideration, Provost please direct inquiries to the President, Code 32A, Naval Amb. Mary Ann Peters War College, 686 Cushing Road, Newport, Rhode Island 02841-1207, or contact the Press staff at the telephone, fax, Dean of Naval Warfare Studies or e-mail addresses given. Robert C. Rubel Reproduction and printing is subject to the Copyright Act Director of China Maritime Studies Institute of 1976 and applicable treaties of the United States. This Dr. Lyle J. Goldstein document may be freely reproduced for academic or other noncommercial use; however, it is requested that Naval War College Press reproductions credit the author and China Maritime Director: Dr.
    [Show full text]
  • Effects of Eddy Variability on the Circulation of the Japan/ East Sea
    Journal of Oceanography, Vol. 55, pp. 247 to 256. 1999 Effects of Eddy Variability on the Circulation of the Japan/ East Sea 1 1 2 G. A. JACOBS , P. J. HOGAN AND K. R. WHITMER 1Naval Research Laboratory, Stennis Space Center, Mississippi, U.S.A. 2Sverdrup Technology, Inc., Stennis Space Center, Mississippi, U.S.A. (Received 5 October 1998; in revised form 17 November 1998; accepted 19 November 1998) The effect of mesoscale eddy variability on the Japan/East Sea mean circulation is Keywords: examined from satellite altimeter data and results from the Naval Research Laboratory ⋅ Japan Sea, Layered Ocean Model (NLOM). Sea surface height variations from the Geosat-Exact ⋅ eddies, ⋅ altimeter, Repeat Mission and TOPEX/POSEIDON altimeter satellites imply geostrophic velocities. ⋅ At the satellite crossover points, the total velocity and the Reynolds stress due to numerical model- ing, geostrophic mesoscale turbulence are calculated. After spatial interpolation the momentum ⋅ Reynolds stress. flux and effect on geostrophic balance indicates that the eddy variability aids in the transport of the Polar Front and the separation of the East Korean Warm Current (EKWC). The NLOM results elucidate the impact of eddy variability on the EKWC separation from the Korean coast. Eddy variability is suppressed by either increasing the model viscosity or decreasing the model resolution. The simulations with decreased eddy variability indicate a northward overshoot of the EKWC. Only the model simulation with sufficient eddy variability depicts the EKWC separating from the Korean coast at the observed latitude. The NLOM simulations indicate mesoscale influence through upper ocean–topographic coupling. 1. Introduction Lie et al., 1995).
    [Show full text]
  • Echinococcus Multilocularis Detected in Slaughtered Pigs in Aomori, The
    Jpn. J. Infect. Dis., 63, 2010 Laboratory and Epidemiology Communications Echinococcus multilocularis Detected in Slaughtered Pigs in Aomori, the Northernmost Prefecture of Mainland Japan Masaaki Kimura, Akira Toukairin, Hajime Tatezaki, Seiko Tanaka, Kunihiro Harada, Junichirou Araiyama, Hiroshi Yamasaki1, Hiromu Sugiyama1, Yasuyuki Morishima1, and Masanori Kawanaka1* Aomori Prefectural Towada Meat Inspection Center, Aomori 034-0001; and 1Department of Parasitology, National Institute of Infectious Diseases, Tokyo 162-8640, Japan Communicated by Tomoyoshi Nozaki (Accepted December 21, 2009) Echinococcus multilocularis is a causative agent of human Among inspections carried out from FY2005 to FY2008 alveolar echinococcosis. The distribution of the parasite in under this program, the number of pigs with liver samples Japan was thought to be limited to the northernmost insular displaying white nodular lesions suggestive of E. multilocula- prefecture of Hokkaido, where the Tsugaru Strait acts as a ris infection for each year was 27, 44, 25, and 13, represent- natural physical barrier against migration to Honshu, the ing a total of 109 (Table 1). Histopathological examination mainland of Japan; however, in Aomori Prefecture, situated of the lesions did not confirm a single case of E. multilocularis in the northernmost part of Honshu, E. multilocularis infec- infection, and the whitish nodules were diagnosed as lymph tion in pigs was first reported in August and December 1998, follicle formation, granulomatous inflammation, interstitial when Aomori Prefectural Towada Meat Inspection Center hepatitis, hepatic cysts, parasitic hepatitis (probably caused (Towada MIC) detected the parasite during postmortem in- by the passage of ascarid larvae), etc. In FY2008, liver tissue spections of livers from three pigs. The infected pigs had all was analyzed in 13 cases, and E.
    [Show full text]
  • Sea of Japan a Maritime Perspective on Indo-Pacific Security
    The Long Littoral Project: Sea of Japan A Maritime Perspective on Indo-Pacific Security Michael A. McDevitt • Dmitry Gorenburg Cleared for Public Release IRP-2013-U-002322-Final February 2013 Strategic Studies is a division of CNA. This directorate conducts analyses of security policy, regional analyses, studies of political-military issues, and strategy and force assessments. CNA Strategic Studies is part of the global community of strategic studies institutes and in fact collaborates with many of them. On the ground experience is a hallmark of our regional work. Our specialists combine in-country experience, language skills, and the use of local primary-source data to produce empirically based work. All of our analysts have advanced degrees, and virtually all have lived and worked abroad. Similarly, our strategists and military/naval operations experts have either active duty experience or have served as field analysts with operating Navy and Marine Corps commands. They are skilled at anticipating the “problem after next” as well as determining measures of effectiveness to assess ongoing initiatives. A particular strength is bringing empirical methods to the evaluation of peace-time engagement and shaping activities. The Strategic Studies Division’s charter is global. In particular, our analysts have proven expertise in the following areas: The full range of Asian security issues The full range of Middle East related security issues, especially Iran and the Arabian Gulf Maritime strategy Insurgency and stabilization Future national security environment and forces European security issues, especially the Mediterranean littoral West Africa, especially the Gulf of Guinea Latin America The world’s most important navies Deterrence, arms control, missile defense and WMD proliferation The Strategic Studies Division is led by Dr.
    [Show full text]
  • View Oirase’S Fresh Greenery in Spring and the Changing Colors of Tsutanuma in Autumn
    Aomori’s Nature Parks Majestic & Breathtaking Aomori Nature Parks Website http://www.shirakami-visitor.jp/aomoris-nature-parks The eternal colors of the four seasons continuing into future 01 The Milky Way at the Kayano Highlands Towada-Hachimantai National Park Aomori is an unexplored location in the north with flowers blossoming in spring and the blue ocean shining in summer. When the trees turn a burning red in autumn, it will soon be winter, a world of white and silver. The incredible scenery of mother nature will steal your heart. Be in awe of nature As one interacts with nature, slowly walking along a mountain road or shore, one begins to feel in awe of nature’s majesty. Enclosed by the ocean on three sides, Shimokita Hanto Aomori’s the climate differs between the Sea of Japan side and Quasi-National Park the Pacific Ocean side, allowing Aomori to boast of a wide variety of landscapes and plants. Nature Parks Aomori has 11 nature parks with outstanding scenery. Sanriku Fukko Towada-Hachimantai Tsugaru (Reconstruction) Quasi-National Park National Park National Park Asamushi-Natsudomari Ashino Chishogun Prefectural Natural Park Prefectural Natural Park National Park Iwaki Kogen Prefectural Natural Park Towada-Hachimantai National Park Shimokita Hanto Tsugaru Quasi-National Park Quasi-National Park Shirakami-Sanchi Natural World Heritage Site Kuroishi Onsenkyo Prefectural Natural Park Sanriku Fukko Tsugaru Shirakami (Reconstruction) Prefectural Natural Park Quasi-National Park National Park Owani Ikarigaseki Onsenkyo Nakuidake Prefectural
    [Show full text]
  • INDEX of Records of the U. S. Strategic Bombing Survey; Entry 55, Carrier-Based Navy and Marine Corps Aircraft Action Reports, 1944-1945
    INDEX of Records of the U. S. Strategic Bombing Survey; Entry 55, Carrier-Based Navy and Marine Corps Aircraft Action Reports, 1944-1945 (1) Task Group 12.4 Action Report of Task Group 12.4 against Wake Island, 13 June 1945 through 20 June 1945 ※Commander Task Group 12.4 (Commander Carrier Division 11). (2) Task Group 38.1 Report of Operations of Task Group 38.1 against the Japanese Empire 1 July 1945 to 15 August 1945 ※Commander Task Group 38.1 (Commander Carrier Division 3 - Rear Admiral T. L. Sprague, USN, USS Bennington, Flagship). (3) Task Group 38.4 Action Report, Commander Task Group 38.4, 2 July to 15 August 1945, Strikes against Japanese Home Islands ※Commander Task Group 38.4 (Commander Carrier Division 6, Rear Admiral A. W. Radford, US Navy, USS Yorktown, Flagship). (4) Task Group 52.1.1 Report of Capture of Okinawa Gunto, Phases I and II, 24 May 1945 to 24 June 1945 ※Commander Task Unit 52.1.1(24 May to 28 May), Commander Task Unit 32.1.1. Action Report, Capture of Okinawa Gunto, Phases 1 and 2 - 21 March 1945 to 24 May 1945 ※Commander Task Unit 52.1.1 (Support Carrier Unit 1) from 9 March 1945 to 10 May 1945 and CTG Task Unit 52.1.1 from 17 May to 24 May 1945 (Commander Carrier Division 26). (5) Task Group 52.1.2 Action Report - Capture of Okinawa Gunto, Phases 1 and 2, 21 March to 29 April 1945 ※Commander Task Unit 52.1.2 (21 March - 29 April, incl) and Commander Task Unit 51.1.2 (21-25 March, inclusive) (Commander Car-rier Division 24).
    [Show full text]
  • Aomori Cycling
    AOMORI CYCLING Up close and personal with the incredible nature and culture of Aomori Aomori Cycling Up close and personal with the incredible nature and culture of Aomori Surrounded by ocean on all sides and blessed by incredible nature such as Shirakami-Sanchi and Lake Towada, each region in Aomori Prefecture enjoys its own unique history, culture and delicacies. Cycling Aomori is the perfect way to discover the intricacies of these individual regions. If you are ready, then jump on your bike and let's head off to explore the beauty of Aomori! 9 1 Course 1 NATSUDOMARI 11 2 Course 2 TOWADA・OIRASE 13 3 Course 3 HIROSAKI 15 4 Course 4 NISHIKAIGAN 17 5 Course 5 OKU-TSUGARU AOMORI 19 6 Course 6 SHIMOKITA 21 7 Course 7 LAKE OGAWARA CYCLING 23 Course 8 HACHINOHE Up close and personal with the incredible nature and culture of Aomori 8 25 33 27 35 29 37 31 7 8 03 02 04 05 06 01/The masses of blue net stored at the port are shellfish baskets, used for cultivating scallops. It's like riding through a maze. 02/Old fishing vessels of all shapes and sizes are dotted around the Natsudomari Peninsula. 03/Showing off the size of the scallops at "Hotate Hiroba," which has a giant scallop as its signboard. You can learn about scallop cultivation on the second floor.04 /At Yogoshiyama Forest Park you can see over 3,000 varieties of succulents. 05/Two men and a cat taking a break from cycling beside the tetrapod seawall.
    [Show full text]
  • Important-Straits-Of-The-World
    IMPORTANT STRAITS OF THE WORLD 2020 IASGRAM WWW.IASGRAM.IN 1 IASGRAM Bab-el-Mandeb The Bab-el-Mandebis a strait located between Yemen on the Arabian Peninsula, and Djibouti and Eritrea in the Horn of Africa. It connects the Red Sea to the Gulf of Aden. The Bab-el-Mandeb acts as a strategic link between the Indian Ocean and the Mediterranean Sea via the Red Sea and the Suez Canal. 2 IASGRAM Bass Strait: Bass Strait is a sea strait separating Tasmania from the Australian mainland, specifically the state of Victoria. There are over 50 islands in Bass Strait. Major islands include: King Island Three Hummock Island Hunter Island Robbins Island 3 civilmentors.com Bering Strait: The Bering Strait is a strait of the Pacific, which separates Russia and the United States slightly south of the Arctic Circle at about 65° 40' N latitude. The eastern coast belongs to the U.S. state of Alaska. The western coast belongs to the Chukotka Autonomous Okrug, a federal subject of Russia. 4 civilmentors.com Bosporus strait: The Bosporus also known as the Strait of Istanbul, is a narrow, natural strait .It forms part of the continental boundary between Europe and Asia, and divides Turkey by separating Anatolia from Thrace. It is the world's narrowest strait used for international navigation, the Bosporus connects the Black Sea with the Sea of Marmara, and, by extension via the Dardanelles, the Aegean and Mediterranean seas. 5 civilmentors.com Cook Strait: Cook Strait is a strait that separates the North and South Islands of New Zealand.
    [Show full text]
  • Spatiotemporal Variations in the Stress Field In
    Maeda et al. Earth, Planets and Space (2020) 72:117 https://doi.org/10.1186/s40623-020-01245-8 EXPRESS LETTER Open Access Spatiotemporal variations in the stress feld in the northeasternmost part of the NE Japan arc: constraints from microearthquakes Sumire Maeda1* , Toru Matsuzawa2 , Tomomi Okada2, Hiroshi Katao3, Takeyoshi Yoshida2 , Masahiro Kosuga4 and Makoto Otsubo1 Abstract We determined focal mechanism solutions of microearthquakes and examined the stress feld in the low-seismicity region from southern Hokkaido to eastern Aomori, NE Japan. The stress felds determined in this study comprise (1) a reverse faulting stress regime in southern Hokkaido with the axis of maximum compressional stress (σ1) being sub- horizontal and trending WNW–ESE, and (2) a stress regime in eastern Aomori to Tsugaru Strait that shows temporal variations and diferential stress of less than tens of MPa. The spatiotemporal variation in stress from eastern Aomori to Tsugaru Strait might refect the efects of the upper-plate bending and the 2011 Mw 9.0 Tohoku-Oki earthquake. It also indicates that the compressional stress caused by the descending Pacifc plate is relatively weak, which is similar to other areas in eastern parts of the NE Japan arc. Keywords: Focal mechanism, Stress feld, Low-seismicity area, Microseismicity, Forearc, Northeastern Japan, Pacifc plate subduction, Kurile arc Introduction in low-seismicity areas. However, to properly understand Te stress feld in inland areas of NE Japan is generally earthquake generation mechanisms, it is necessary to recognized as being associated with a WNW–ESE com- investigate the stress feld in low-seismicity areas as well pressional reverse-faulting stress regime (e.g., Townend as in areas with high seismicity.
    [Show full text]
  • State of the Marine Environment Report for the NOWPAP Region (SOMER 2)
    State of the Marine Environment Report for the NOWPAP region (SOMER 2) 2014 1 State of Marine Environment Report for the NOWPAP region List of Acronyms CEARAC Special Monitoring and Coastal Environmental Assessment Regional Activity Centre COD Chemical Oxygen Demand DDTs Dichloro-Diphenyl-Trichloroethane DIN, DIP Dissolved Inorganic Nitrogen, Dissolved Inorganic Phosphorus DO Dissolved Oxygen DSP Diarethic Shellfish Poison EANET Acid Deposition Monitoring Network in East Asia EEZ Exclusive Economical Zone FAO Food and Agriculture Organization of the United Nations FPM Focal Points Meeting GDP Gross Domestic Product GIWA Global International Waters Assessment HAB Harmful Algal Bloom HCHs Hexachlorcyclohexane compounds HELCOM Baltic Marine Environment Protection Commission HNS Hazardous Noxious Substances ICARM Integrated Coastal and River Management IGM Intergovernmental Meeting IMO International Maritime Organization 2 JMA Japan Meteorological Agency LBS Land Based Sources LOICZ Land-Ocean Interaction in the Coastal Zone MAP Mediterranean Action Plan MERRAC Marine Environmental Emergency Preparedness and Response Regional Activity Center MIS Marine invasive species MTS MAP Technical Report Series NGOs Nongovernmental Organizations NIES National Institute for Environmental Studies, Japan NOWPAP Northwest Pacific Action Plan OSPAR Convention for the Protection of the Marine Environment of the North-East Atlantic PAHs Polycyclic Aromatic Hydrocarbons PCBs PolyChloro-Biphenyles PCDD/PCDF Polychlorinated dibenzodioxins/ Polychlorinated dibenzofurans
    [Show full text]