• Title/Summary/Keyword: southeastern region

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Distribution and characteristics of Quaternary faults in the coastal area of the southeastern Korean Peninsula: Results from a marine seismic survey (해양 탄성파 탐사 결과로 본 한반도 남동부연안 4기 단층의 분포와 특성)

  • Kim Han-Joon;Jou Hyeong-Tae;Hong Jong-Kuk;Park Gun-Tae;Nam Sang-Heon;Cho Hyun-Moo
    • 한국지구물리탐사학회:학술대회논문집
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    • 2002.09a
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    • pp.46-66
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    • 2002
  • High-resolution multichannel seismic data were collected in the coastal area near the Gori nuclear power plant to investigate Quaternary fault pattern and timing. A 12 channel streamer, a sparker, and a portable recorder were used for data acquisition. Because the group interval of the streamer was 6.25 m and the sparker can generate acoustic waves with the frequency content of up to 500 Hz, the data show a significant improvement both in horizontal and vertical resolution. The area surveyed is covered with 30-40 m thick Holocene sediments that constitute the mud belt along the southeastern coast of Korea. The survey area is characterized by the well discriminated Pleistocene and Holocene boundary and shallow gas-charged zones. A number of Quaternary faults were found in the sediment column, that are nearly vertical and extend north-south. The Quaternary faults, arranged at a spacing of a few hundred meters, suggest that they were formed in response to compression, although some of them reveal extensional characteristics. Locally, faults disrupt Incised-channel fills that are interpreted to have formed in the early stage of transgression after the beginning of the Holocene. Seismic sections suggest that shallow gas in the mud belt sediments made its way upward through the fractured fault planes. The tectonism responsible for the opening of the East Sea has not persisted since the late Miocene, but vigorous Quaternary faulting activity in the vicinity of the southeastern Korean Peninsula indicates that tectonic stability has yet to be achieved in this region underlain by the hotter than normal mantle.

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Sequence Stratigraphy of Late Quaternary Deposits in the Southeastern Continental Shelf, Korea (한국 남동 대륙붕 후 제4기 퇴적층의 시퀀스 층서)

  • 유동근;이치원;최진용;박수철;최진혁
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.8 no.4
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    • pp.369-379
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    • 2003
  • Analysis of high-resolution seismic profiles and sediment data from the southeastern continental shelf of Korea reveals that the late Quaternary deposits consist of a set of lowstand (LST), transgressive (TST), and highstand systems tracts (HST) that corresponds to the sea-level change after the Last Glacial Maximum. LST (Unit I) above the sequence boundary consists of sandy mud or muddy sand deposited during the last glacial period and is confined to the shelf margin and trough region. TST (Unit II) between transgressive surface and maximum flooding surface consists of sandy sediments deposited during the postglacial transgression (15,000-6,000 yr BP). Although TST is widely distributed on the shelf, it is much thinner than LST and HST. On the basis of distribution pattern, TST can be divided into three sub-units: early TST (Unit IIa) on the shelf margin, middle TST (Unit IIb) on the mid-shelf, and late TST (Unit IIc) on the inner shelf, respectively. These are characterized by a backstepping depositional arrangement. HST(Unit III) above the maximum flooding surface is composed of the fine-grained sediments deposited during the last 6000 yrs when sea level was close to the present level and its distribution is restricted to the inner shelf along the coast.

A Study on the Design Improvement of Street Facilities in Jeollabuk-do Province (전라북도 가로시설물의 디자인 제고를 위한 연구)

  • Kim, Sang Hyun;Kim, Hong Bae
    • Journal of the Korean Institute of Rural Architecture
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    • v.25 no.2
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    • pp.1-8
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    • 2023
  • This study reveals the absence of standard design guidelines by region through investigation and analysis centered on public design cases by region in Jeollabuk-do and design elements that can reflect the integration, identity, and diversity of public design in each region by five regions. Through this, the following conclusions could be obtained. First, to improve the quality of street facilities in Jeollabuk-do, the design elements (design motif, color, pattern) applicable to the standard design were analyzed by dividing them into five regions. As a design motif, it was possible to extract patterns containing straight lines, sophistication, dignity, and smartness. In the Northeast region, it is comfortable with the motif of the mountain ridge reflecting geographical characteristics, and it can be extracted elements that contain warm and natural colors. In the southeastern region, patterns that reflect design elements were extracted by applying safe, lively, and peaceful colors with the design motif of curves that blend nature and agriculture. In the southwestern region, design pattern elements that highlight nature, history, and culture were extracted with various cultural assets and natural greenery as motifs. Lastly, in the Saemangeum region, the ocean flow and greenery could be used as a design motif to reflect a positive, clear, future-oriented image in the design spot zones by region. Second, based on the standard design elements (design motive, color, pattern) by region extracted for the standard design development of street facilities in each region in Jeollabuk-do, an integrated zone(Form, structure, material, color, functional element) to which regional design guidelines can be applied. Third, an integrated zone (form, structure, material, color, functional elements) was composed. In addition, design spot zones (patterns and colors in city and county units) that can contain the diversity and identity of each region were designated. By designating design spot zones (patterns and colors in city and county units) that can contain the diversity and identity of each region, standard design development plans (integrated pillars, jaywalking prevention fences, roundabouts (urban type, rural type), street trees) Eight standard designs, including protective covers, street planters, flat benches, light benches, visual media for user guidance, and parking zones for personal mobile devices) were presented.

Gravity Field Interpretation for the Deep Geological Structure Analysis in Pohang-Ulsan, Southeastern Korean Peninsula (한반도 남동부 포항-울산지역 심부 지질구조 분석을 위한 중력장 해석)

  • Sohn, Yujin;Choi, Sungchan;Ryu, In-Chang
    • Economic and Environmental Geology
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    • v.53 no.5
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    • pp.597-608
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    • 2020
  • Even after the Gyeongju earthquake and the Pohang earthquake, hundreds of aftershocks and micro-earthquakes are still occurring in the southeastern part of the Korean Peninsula. These phenomena mean that the stress is constantly working, implying that another huge earthquake may occur in the future. Therefore, the gravity field interpretation method was used to analyze the deep geological structure of the Pohang-Ulsan region in the southeastern Korean Peninsula. First, a gravity survey was performed to collect the insufficient data and to calculate the detailed Bouguer gravity anomaly in the study area. Based on the gravity anomaly data, the location, direction, and maximum depth of deep fault lines were analyzed using the inversion methods "Curvature analysis" and "Euler deconvolution method". As a result, it is interpreted that at least six fault lines(C1~C6) exist in deep depth. The deep fault line C1 is well correlated to the Yeonil Tectonic Line(YTL), suggesting that YTL is extended up to about 4000m deep. The deep fault line C2 consists of several segment faults and well correlated to the fault lines on the surface. Inferred fault lines C3, C4, and C5 have an NW-SE direction, which is parallel to the Ulsan fault. The deep fault line C6 has the direction of NE-SW, and it is interpreted that the eastern boundary fault of Eoil Basin is extended to the deep. Comparing the inferred fault lines with the distribution of micro-earthquakes, the location of the deep fault line C1 is well correlated to the hypocenter of micro-earthquakes. This implies that faults in deep depth are related to the recent earthquakes in the southeastern Korean Peninsula.

Characteristics of Ocean Environment Before and After Coastal Upwelling in the Southeastern Part of Korean Peninsula Using an In-situ and Multi-Satellite Data (다중위성 및 현장관측을 이용한 동해남부 연안용승 발생 전후의 해양환경 특성)

  • Kim, Sang-Woo;Go, Woo-Jin;Kim, Seong-Soo;Jeong, Hee-Dong;Yamada, Keiko
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.16 no.4
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    • pp.345-352
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    • 2010
  • The objective of this paper is to explore the short-term variability of water temperature and chlorophyll a (Chl-a) derived from in-situ and satellite data (NOAA, Sea WiFS and QuikScat) in the upwelling region of the southeastern part of Korean Peninsula in June and August, 2007. Particularly we focused on the spatial variability of sea surface temperature(SST) and Chl-a in the East Korean Warm Current region. In the results of the in-situ data, the peaks of Chl-a in june was shown at a depth of 50m The peaks of Chl-a in August was shown at a depth of 10m at the stations 4 and 5 near the land, and a depth of 30m at the other stations. The Chl-a concentrations in August were also lower than those in june except for station 5. As a result, the peaks of Chl-a in August occurred at a depth of 20~40 m shallower than those of Chl-a in june. This indicates that the nutrient-rich water within the mixed layer depth may be immediately supplied by the coastal upwelling, which is due to the southerly component of wind. The relationship between SST and Chl-a showed a negative correlation, and the high concentration of Chl-a occurred in the cold water area. The southerly wind and the East Korean Warm Current influenced a remarkable offshore movement of the cold water and Chl-a near the coastal area.

Hereditary Testimonies and Medico-historical Facts of the Eminent Brother Doctors Young Hur and Eon Hur (허영(許郢), 허언(許鄢) 형제명의(兄弟名醫)의 가전행적(家傳行蹟)과 의약사실(醫藥事實))

  • Ahn, Sang-Woo
    • Korean Journal of Oriental Medicine
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    • v.15 no.1
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    • pp.1-11
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    • 2009
  • The eminent brother doctors Cho-Gaek Hur (Young Hur) and Cho-Sam Hur (Eon Hur) represent the medical tradition of the southeastern region of Mt. Jirisan incluiding Sancheong. This study investigated and examined their herediatary testimonies and medico-historical facts described in the literature tale, genealogy and family collection of works. At an early age after their family run away to the southern region from the harm of political struggle, they gave up taking the highest-level state examination to recruit ranking officials and set their heart on learning medicine. Their choice of medicine was the second best plan for the survival of their family and descendents from the influence of their ancestors who suffered from the party strife during the late Joseon Dynasty. The case is a good example of the deliberate action of the nobility intellectuals since the late Goryeo and early Joseon dynasties to who made attempts to have the minimum elegance and cause while securing livelihood after they have been collapsed politically. The tale of Cho-Gaek and Cho-Sam is a typical story of eminent doctors which combined reality and fiction about the persons who had outstanding medical skills. In the tale, the elder brother was good at herbal prescriptions and the younger brother was good at acupuncture, contrasting the treatment of administrative internal medicine and insertive acupuncture treatment. It shows that the prepositions for the choice of the treatment method for the public during that period were safety and fast efficacy. In their old age, they wrote a book titled Jinyangsinbang. Another Jinwoosinbang is estimated as a different kind of copy, which was a medical writing from experience that derived from the same original book as Jinyangsinbang. written by Cho-Gaek Hur and it is a valuable medical material that possesses the distinct features of the local medicine during the late Joseon Dynasty. Most of the contents are variations in application using the basis of Dongeuibogam, forming the roots of the traditional Korean medicine in Sancheong region together with the medical activities of the Hur brothers.

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Evaluation of the genetic diversity of six Chinese indigenous chickens

  • Sha, Yuzhu;Gao, Caixia;Liu, Meimei;Zhao, Shengguo
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.10
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    • pp.1566-1572
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    • 2020
  • Objective: The extensive breeding of commercial chickens has led to a sharp decrease in the resources of many indigenous chickens, especially the indigenous chickens in the southeastern coastal region, which are on the verge of extinction, and the indigenous chickens in the northwestern region of China, which are also at risk. However, there are few reports on the evaluation of genetic diversity and conservation of genetic resources of indigenous chickens in remote areas in the Northwest of China. Methods: In the present study, the genetic diversity and phylogenetic relationship of six indigenous chickens from different regions were studied based on variation in mitochondrial DNA control region (D-loop), and the degree of introgression from commercial breeds into these chickens was determined by the amount of haplotype sharing between indigenous and commercial breeds. Results: Twenty-five polymorphic sites and 25 haplotypes were detected in 206 individuals. Principal component analysis showed that the Jingning chicken had the highest genetic diversity among the six indigenous chickens. According to the degree of introgression, the six indigenous breeds may be involved in haplotype sharing with commercial breeds, and the introgression from commercial chickens into the Haidong chicken is the most serious. Conclusion: The genetic uniqueness of indigenous chickens has been eroded, so it is necessary to consider the protection of their genetic resources. Phylogenetic analysis suggests that the six indigenous chickens have two major matrilineal origins: one from Yunnan or its surrounding areas in China and the other from the Indian subcontinent.

The Fluctuation Characteristics of the Water Mass and the Current Structure of the Southeastern Region of The East Sea

  • Lee Chung Il;Cho Kyu Dae
    • Fisheries and Aquatic Sciences
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    • v.3 no.2
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    • pp.97-110
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    • 2000
  • To investigate characteristics of water masses and current structures around Noto Peninsula located in south-east coastal region of the East Sea, observation results of CREAMS (Circulations Research of the East Asian Marginal Seas) cruise and data report of oceanographic observation (Japan Meteorological Agency) in June, 1995 and 1996 were used. Water mass showing characteristics of Tsushima Warm Current (TWC) exists over the continental shelf. The depth is shallower than 200m and its width and thickness are 190km and 200m, respectively. Minimum level of dissolved oxygen occurred at the layers of maximum salinity. In the current structure, a noteworthy phenomenon is that the positions of the high-salinity water (more than 34.6 psu) match well with the distributions of the southwestward flow. In June of 1995 and June of 1996, a southwestward flow were separated into two parts along line C and line G. Current directions derived from the temperature and salinity match well with the distributions of the geostrophic currents in the vertical sections. The isothermal lines and the isohaline, which exist horizontally along the coastal area of the Japan, change abruptly at the frontal area of the Noto Peninsula, then turn toward the center of the East Sea. The dynamic depth anomalies centering around the region far northwest of the Noto Peninsula were relatively high, compared to those of other regions. The isopycnic surface (sigma-t, 25.8) existed near the surface in the central part of the East Sea, but, at the depth of 100m, the isopycnic surface was found in the coastal waters.

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Effects of the 1975 Haicheng Earthquake on the Korean Peninsula (1975년에 발생한 중국 해성지진이 한반도에 미친 영향)

  • 추교승
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1998.10a
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    • pp.210-221
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    • 1998
  • In the period from the year 1500 to 1980. at least 14 large earthquake with epicenters in the northeastern China and Yellow Sea were felt or destructive in the Korean Peninsula. The most sigmificant events among them were the 1668 July 25 Tancheng earthquake of mamnitude 8.5, and the 1975 Feb. 4 Haicheng earthquake of magnitude 7.3. The Haicheng earthquake of the year 1975 in am extraordinary one among those occurred in the northeastern China in the 20th century in the sense the Shake of the event affected all over the Korean Peninsula. The tremor was felt even at the southeastern tip of the Korea and northern part of Kyushu 700km far away from the epicenter. In order to see the variation and trend of the effect of the Haicheng earthquake on the Korean Peninsula, the two data sets of the northern and southern parts of the peninsula were merged into one combined data set. The spatial variation of intensity shows smooth decrease from the value 4 of the northwestern region near the source to the value 1 of the Cheju Island and Kjushu. However, there are four regions of locally high intensity value. They are the region along downstream of Abrok(Yalu) River with intensity 5, the region around Shinpo of intensity 4, the area comprising Seoul and Chuncheon Cities of intensity 4, and Pohang-Pusan area of intensity 3. We suppose that there might be three types of possible mechanisms. The first one is concerned with the lateral inhomogeneity of velocity in the crust caused by wide distribution of relatively fractured rock. The second one is related with reflections of surface waves caused by the crestal thinning effect at border regions of the Peninsular in contact with the Ulleung Basin and the Japan Basin. The third possibility is local site effect caused by thick Tertiary or Quaternary rocks and soil layers.

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Palaeomagnetic Study of Sedimentary and Igneous Rocks in the Yangsan Strike-slip Fault Area, SE Korea (양산단층지역에 분포하는 퇴적암 및 화성암류에 대한 고자기 연구)

  • Kang, Hee-Cheol;Kim, In-Soo;Son, Moon;Jung, Hyun-Jung
    • Economic and Environmental Geology
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    • v.29 no.6
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    • pp.753-765
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    • 1996
  • It is a well known fact that the remanent magnetization direction of the Tertiary rocks is deflected significantly clockwise (about $50^{\circ}$) in the Tertiary basins of the southeastern part of Korean peninsula. This fact has been interpreted as an evidence of north-south spreading of the East Sea (Sea of Japan) and dextral strike-slip motion of the Yangsan fault. As deflection (rotation) of remanent magnetizations is frequently reported from various regions of the world in the vicinities of strike-slip fault, such phenomena are to be expected in the Yangsan fault region also. It was the purpose of this study to clarify whether such premise is right or not. A total of 445 independently oriented core samples were collected from Cretaceous rocks of various lithology (sedimentary rocks, andesites and I-type granites) in the Yangsan fault area. In spite of through AF and thermal demagnetization experiments, no sign of remanent magnetization deflection was found. Instead, palaeomagnetic poles calculated from formation-mean ChRM directions are very similar to those of contemporary (Barremian, and late Cretaceous-Tertiary) sedimentary and plutonic rocks in the other parts of $Ky{\check{o}}ngsang$ basin as well as those of China. Therefore, possibility of tilting of granite plutons and horizontal block rotation of study area is excluded. It is also concluded that the Yangsan fault did not take any significant role in the Cenozoic tectonic evolution of southeast Korea and the East Sea region. The boundary between rotated and unrotated region of remanent magnetization is not the Yangsan fault line, but must lie further east of it.

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