• Title/Summary/Keyword: Northern Korean peninsula

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The Spatial Distribution and Change of Frequency of the Yellow Sand Days in Korea (한국의 황사 발생 빈도 분포와 변화 분석)

  • Kim, Sunyoung;Lee, Seungho
    • Journal of Environmental Impact Assessment
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    • v.15 no.3
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    • pp.207-215
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    • 2006
  • The purpose of this paper is to analyze the spatial distribution and change of the frequency of Yellow Sand days and to examine their relationship with atmospheric circular characteristics at the surroundings of the Korean peninsula. Yellow Sand days data are used by intensity, Siberian High Index and monthly mean temperature of the Northern Hemisphere. In the Middle-western region, the occurrence frequency of Yellow Sand days was higher during the study period (1973-2004). Also, the occurrence frequency of Yellow Sand days increased to latter half 16 years compared with the first half 16 years, and be clearer in Middlewest regions. Yellow Sand days frequency increased, and the trend was distinct in the Jungbu region during the study period. Increasing trend of Yellow Sand days frequency was significant for the recent 22 years. Yellow Sand days had a negative relationship with Siberian High Index in February and March. Therefore, Siberian High Index became weaker in the spring, and possibility for the occurrence of Yellow Sand days was generating larger. Yellow Sand days had a positive relationship in monthly mean temperature of the Northern Hemisphere. Especially, the case of the strong Yellow Sand days is significant. Recently, global warming might be affecting the occurrence of strong Yellow Sand days.

The Characteristics of Asian Dust and Comprehensive Countermeasure (황사의 발생전망과 종합대책)

  • Kim, Yong-Su
    • Journal of the Korean Professional Engineers Association
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    • v.41 no.2
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    • pp.68-74
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    • 2008
  • Asian Dust is a seasonal phenomenon which affects much of East Asia mostly in spring. The dust and sand storm originate in the deserts of Mongolia. northern China, and Kazakhstan. Asian Dust is carried eastward by prevailing winds, and pass over China, the Korean Peninsula. and Japan. In recent years, Republic of Korea, China, and Japan have participated in projects associated with implementation of observation network and reforestation in the source region. The information of Asian Dust can be exchanged in real time among the east Asian countries through the international co-operation.

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Discussion on the Quaternary fault movement at Yugye-ri area in the northern part of Yangsan Fault (양산단층 북부 유리계 일대의 신기 단층운동 소고)

  • 경재복
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2001.04a
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    • pp.66-73
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    • 2001
  • Yangsan fault in the southeastern part of Korean peninsula has been locally reactivated along a prexisted fault during the late Pleistocene time. Geomorphological evidence of the reactivation is revealed at the northern segment(Yugye-ri, Tosung-ri areas) of the Yangsan fault. The reactivation is distinctively characterized by fault gouge and fracture zone with high frequency in the Yugye-ri area. Obique slip separation of the area is about three meters of the middle terrace. The cumulative vertical displacement is recognized after the formation of the middle terrace. Age of the reactivated faulting is constrained to during the formation of dissected valley deposits. Average vertical slip based on paleo-event is inferred to about 0.5-0.7 meter in this area.

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Spatial Variation of the Polar Front in relation to the Tsushima Warm Current in the East Sea (동해에서 쓰시마난류의 변동과 관련한 극전선의 공간적 변화)

  • 이충일;조규대;최용규
    • Journal of Environmental Science International
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    • v.12 no.9
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    • pp.943-948
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    • 2003
  • Variation of the polar front in the East Sea is studied using temperature and dissolved oxygen data obtained from Japan Meteorological Agency from 1972 to 1999. Variation of the polar front in the East Sea has a close relation to the variation of the Tsushima Warm Current (TWC). When the TWC spreads widely in the East Sea, polar front moves northward. The spatial variation of the polar front is greater in the southwestern area of the East Sea and the northern area of Tsugaru Strait where the variation of the TWC's distribution area is greater than those in others of the East Sea. Hence, in the southeastern area of the East Sea, that is, between near Noto peninsula and Tsugaru Strait, the spatial variation of the polar front is not so wide as in the southwestern area because the flow of TWC is stable.

Distribution characteristics of Manchurian and China-Japan-Korea flora in Korean Peninsula

  • Kim, Nam Shin;Lim, Chi Hong;Cha, Jin Yeol;Cho, Yong Chan;Jung, Song Hie;Jin, Shi Zhu;Nan, Ying
    • Journal of Ecology and Environment
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    • v.46 no.3
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    • pp.259-272
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    • 2022
  • Background: The Korean Peninsula exhibits a characteristic graded floral distribution, with northern (Manchurian flora) and southern (China-Japan-Korea flora) lineage species coexisting according to climatic and topographical characteristics. However, this distribution has been altered by climate change. To identify ecosystem changes caused by climate change and develop appropriate measures, the current ecological status of the entire Korean Peninsula should first be determined; however, analysis of the current floral distribution in North Korea has been hampered for political reasons. To overcome these limitations, this study constructed a database of floral distributions in both South and North Korea by integrating spatial information from the previously established National Ecological Survey in South Korea and geocoding data from the literature on biological distributions published in North Korea. It was then applied to analyze the current status and distribution characteristics of Manchurian and China-Japan-Korea plant species on the Korean Peninsula. Results: In total, 45,877 cases were included in the Manchurian and China-Japan-Korea floral distribution database. China-Japan-Korea species were densely distributed on Jeju-do and along the southern coast of the Korean Peninsula. The distribution density decreased as the latitude increased, and the distributions reached higher-latitude regions in the coastal areas compared with the inland regions. Manchurian species were distributed throughout North Korea, while they were densely distributed in the refugia formed in the high-elevation mountain regions and the Baekdudaegan in South Korea. In the current distribution of biomes classified according to the Whittaker method, subtropical and endemic species were densely distributed in temperate seasonal forest and woodland/shrubland biomes, whereas boreal species were densely distributed in the boreal forest biome Korean Peninsula, with a characteristic gradation of certain species distributed in the temperate seasonal forest biome. Factor analysis showed that temperature and latitude were the main factors influencing the distribution of flora on the Korean Peninsula. Conclusions: The findings reported herein on the current floral distribution trends across the entire Korean Peninsula will prove valuable got mitigating the ecological disturbances caused by ongoing climate change. Additionally, the gathered flora data will serve as a basis for various follow-up studies on climate change.

Origin of the Korean Mandarin Fish, Siniperca scherzeri and Its Molecular Phylogenetic Relationships to Other Siniperca Fishes (한국산 쏘가리의 기원과 분자계통진화적 위치)

  • Kim, Maeng-Jin;Song, Choon-Bok
    • Korean Journal of Ichthyology
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    • v.23 no.2
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    • pp.95-105
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    • 2011
  • To explain the origin of the Korean mandarin fish (Siniperca scherzeri), phylogenetic relationships and DNA polymorphism among Siniperca fishes have been investigated based on mitochondrial cytochrome b DNA sequences. As a result, S. roulei were firstly differentiated early in the evolution of Siniperca fishes and the other six species (S. schezeri, S. undulata, S. fortis, S. obscura, S. knerii and S. chuatsi) were evolved slightly later. However, the order of species differentiation among six species was not clear because the nodes of their phylogeny were poorly resolved. The constructed molecular phylogeny revealed three genetically distinct groups of local populations of S. scherzeri. The first group (group 1) is the local populations of Korean peninsula and northern China including Lioaning and Henan. The second one (group 2) is the local populations of Anhui, Fujian and Guangxi. The third one (group 3) is the local population of Zhejiang. The number of nucleotide differences in base pairs were 31~43 between group 1 and 2; 37~44 between group 2 and 3; 27~29 between group 1 and 3; and 1~5 within group 1. Thus, the Korean mandarin fish was likely to be originated from the northern China local population which was isolated from the middle or southern China local populations during the Cenozoic Pliocene. Low level of sequence divergence between Korean mandarin fish populations and northern China population indicated a recent expansion of distribution ranges from northern China to Korean peninsula.

Incision and Geomorphic Development of Rivers on Eastern and Western Sides of the Northern Sobaek Mountains (소백산맥 북부 영동영서 하천의 하각과 지형 발달)

  • Cho, Young-Dong;Park, Chung-Sun;Lee, Gwang-Ryul
    • Journal of The Geomorphological Association of Korea
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    • v.24 no.2
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    • pp.27-40
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    • 2017
  • This study tries to analyze topographic distribution and characteristics of as well as formative age and incision rate of fluvial terraces in Danyang River on western side and Geum River on eastern side of the northern Sobaek Mountains and to estimate geomorphic development during the late Quaternary in the mountains regarded as one of the uplift axes in the Korean Peninsula. OSL age dating shows that the fluvial terrace I with an altitude above riverbed of approximately 7~13 m in Danyang River has a formative age of approximately 18 ka (MIS 2) and incision rate in the river is approximately 0.156~0.194 m/ka based on the age. Altitudes above riverbed of the fluvial terrace I in Geum River range from approximately 7 to 14 m and the terrace is thought to be older than 70 ka based on age result from aeolian sediments above the terrace deposits, suggestive of an incision rate less than approximately 0.10 m/ka. These results indicate lower uplift rate in the northern Sobaek Mountains than in the Taebaek Mountains. Moreover, it can be suggested that the northern Sobaek Mountains has experienced asymmetric uplift during the late Quaternary, because the river on western side of the northern Sobaek Mountains shows greater uplift rate than the eastern side river does. Low incision rate in Geum River can be attributed to low altitude of the river basin with little difference in altitude from the base level as well as to gentle river slope due to influence of Nakdong River.

Characteristics and Provenance of Heavy Minerals in the Yellow Sea and Northern East China Sea (황해 및 동중국해 북부의 중광물 특성과 기원)

  • Koo, Hyo Jin;Lee, Bu Yeong;Cho, Hyen Goo
    • Economic and Environmental Geology
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    • v.53 no.5
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    • pp.505-515
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    • 2020
  • The Yellow Sea and northern East China Sea contain a transgressive sand layer. Numerous sedimentary studies have been carried out in these sand deposits using seismic exploration and core sediment techniques, but few mineralogical studies have been reported. The major purposes of this study are to describe the distributions of heavy minerals throughout the Yellow sea and northern East China Sea and to identify the provenance of coarse sediments using the mineral chemistry. Eight heavy mineral species were identified in the study area (epidote, amphibole, garnet, zircon, sphene, rutile, apatite, and monazite). The study region was divided into six areas (areas A to F) based on heavy mineral distributions and sampling locations. In mineral chemistry, the amphiboles present are classified as edenite and hornblende in the calcic amphibole group, and the garnets are identified primarily as almandine in the pyralspite group. A combined data set of heavy mineral distributions and mineral chemistry showed clear differentiation of the characteristics of the six classified areas, enabling determination of provenance and sedimentary environment. Area A and B in the eastern Yellow Sea were originated from the Korean peninsula, and these regions showed different heavy mineral characteristics by tidal current and coastal current. In addition, monazite was only found in the area B and could be used as an indicator from the southwestern Korean peninsula. Area D and E in the western Yellow Sea showed the characteristics of sediments originating from the Huanghe, and sediment in the area E was derived from the Changjiang. Area C in the northern East China Sea appeared to have Changjiang-origin sediment, and abundant apatite indicated that area C was formed close to the Last Glacial Maximum.