• Title/Summary/Keyword: rocky

Search Result 280, Processing Time 0.025 seconds

ENGINEERING GEOLOGICAL STUDIES ON THE SUBMERGED TOMB OF KING MUNMU, SHILLA DYNASTY, KOREA (문무대왕 수증릉에 대한 지질공학적 연구)

  • HoWoongShon;SeongBeomKim
    • Journal of the Korean Geophysical Society
    • /
    • v.6 no.3
    • /
    • pp.139-153
    • /
    • 2003
  • Subsurface information is one of the most important factors in the archaeological excavation. To obtain the information on the underground, geophysical prospecting is becoming a popular method. This study is on the small rocky islands located 200m away from the shoreline of Gampo, Gyeongju city, Korea. According to the historical records and field surveys, it was revealed as the tomb of King Munmu of Shilla Dynasty. However, the questions and debates, such as whether it is really the tomb of King Moonmu or not, and whether it is a buried place or not, are still remains, in addition to the incompletion of precise surveying and scientific studies. The scope of this study contains the researches on the above problems and debates using the geophysical and geological methods and techniques. The rocky islands around the submerged Tomb of King Moonmu is composed of granite, and sag exists inside of the islands. Sea water enters through the east groove by wave and is drained to the west slot by hydraulic gradient, since west slot is 15cm lower than the east. Sag inside of the islands is believed to be extended and widened from pre-existed sinkage by applying tools like chisel in the joints and cracks. It is concluded that the submerged megalith inside of sag was from the rock block which was developed by joints. Geophysical surveys reveal that there is no artificial structure or stone/china/steel chest, under the m egalith and rocky island. Researches show that the tomb of King Moonmu was constructed in the small rocky island artificially. However, the evidences show that planners and constructors of the tomb made every possible effort to preserve the natural environment and condition. It is strongly believed that the megalith was sort of alter to sprinkle bone-ash rather than buried place.

  • PDF

Fish Assemblages by SCUBA Observations in the Water off Tongyeong, Korea (잠수관찰을 통한 경남 통영 연안의 어류상)

  • Gwak, Woo-Seok;Lee, Seung-Hwan;Lee, Yong-Deuk
    • Korean Journal of Ichthyology
    • /
    • v.28 no.2
    • /
    • pp.100-109
    • /
    • 2016
  • Species composition and distribution characteristics of fish were determined by monthly underwater visual census from September. 2013 to August, 2014 at Yeongunri off Tongyeong, Korea. The study area was divided into five habitat types by depth and substrate: (1) sand bottom as depth of 0~2 m, (2) seagrass bed of 2~5 m, (3) rocky outcrop of 0~2 m, (4) rocky bottom of 2~5 m, (5) sandy mud bottom of 5~8 m. A total of 1,673 individuals belonging to 43 species in 26 families were recorded during the study period. The number of species tended to decrease after October, 2013 and increase from March, 2014 showing the highest number in October (autumn), and lowest in January (winter). In terms of the number of species, Gobiidae was the most dominant family (7 species), followed by Scorpaenidae (4 species). Embiotocidae was the most abundant (26.1% in total number of individuals), followed by Scorpaenidae (19.9%) and Gobiidae (19.3%). The dominant species were Sebastes inermis (19.2%), Ditrema temminckii (13.1%), and Neoditrema ransonnetii (12.9%). The number of species and abundance were relatively high at the depth between 2 and 5 m on seagrass bed and rocky bottom, whereas they were lower at the depth between 0 and 2 m on the sand bottom, suggesting that seagrass beds and rocky bottoms provided the diverse habitats for various fish species in this sea.

Seasonal Variations in the Species Composition of Fisheries Resources Caught by Trammel Net in the Uljin Marine Ranching Area, East Sea (울진바다목장에서 자망으로 어획된 수산자원의 종조성과 계절변동)

  • Yoon, Byoung Sun;Park, Jeong-Ho;Yoon, Sang Chul;Yang, Jae Hyeong;Lee, Sung-Il;Kim, Jong-Bin;Choi, Young-Min;Sohn, Myoung Ho
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.48 no.6
    • /
    • pp.947-959
    • /
    • 2015
  • Variations in the species composition, biomass and size distribution of fisheries resources in the Uljin marine ranching area were investigated using trammel nets at two stations (artificial reef and natural rocky area) from 2009 to 2010. During the survey, a total of 74 species were sampled with a mean density of 132 ind./net and mean biomass of 21.56 kg/net. In the natural rocky area, a total of 45 species were sampled at a mean density of 202 ind./net and mean biomass of 28.81 kg/net, while in the artificial reef area, samples included a total of 56 species, with means of 62 ind./net and 14.30 kg/net. The dominant species, comprising over 3% of the total number of individuals, were Suberites ficus (30.8%), Ovalipes punctatus (19.2%), Paralichthys olivaceus (11.7%), Pleuronectes herzensteini (4.7%), Kareius bicoloratus (3.5%), Pseudopleuronectes yokohamae (3.5%) and Eopsetta grigorjewi (3.0%). The dominant species, in terms of biomass, comprising over 5% of the total biomass, were P. olivaceus (22.1%), S. ficus (18.7%), O. punctatus (7.2%), Hexagrammos otakii (6.6%), P. yokohamae (5.7%), K. bicoloratus and P. herzensteini (5.3%). A cluster analysis and non-metric multidimensional scaling (nMDS) analysis based on the Bray-Curtis similarity of fourth root transformed data for number of species and individuals, was divided into two groups: the artificial reef area (group A) and the natural rocky area (group B).

Effects of Forest Management Practices and Environment on Occurrence of Armillaria Species

  • Kim, Mee-Sook;Klopfenstein, Ned B.;Mcdonald, Geral I.
    • Journal of Korean Society of Forest Science
    • /
    • v.99 no.2
    • /
    • pp.251-257
    • /
    • 2010
  • Influences of environment (indicated by plant associations) and forest management practices on the distribution of Armillaria spp. and genets (vegetative clones) were investigated. A total of 142 isolates of Armillaria was collected from various host trees on pristine and managed sites (thinned and/or fertilized) growing in relatively wet and dry environments in eastern Washington, U.S.A. The incidence of Armillaria spp. was significantly higher in the relatively wetter sites than the relatively drier sites, as indicated by plant associations. However, no differences in Armillaria occurrence were found among different forest management practices (control vs. thinned vs. thinned and fertilized) within both wetter and drier sites. Incidence of Armillaria was significantly different among conifer and shrub species. The highest proportion with Armillaria was found on grand fir (Abies grandis). Based on pairing tests and rDNA sequencing, the 142 isolates were comprised in a total of 20 genets representing three Armillaria species. More diverse Armillaria spp. were found in both relatively wetter and relatively drier sites within the undisturbed control plots, compared to plots disturbed by forest management practices. The results from this study provide baseline information toward understanding how environment and forest management practices influence incidence and diversity of Armillaria species and genets.

Structure of Intertidal Macroalgal Community at the Yeonpyeongdo Islets, Korea

  • Choi, Han-Gil;Yoo, Hyun-Il;Song, Hong-In
    • Fisheries and Aquatic Sciences
    • /
    • v.11 no.3
    • /
    • pp.159-165
    • /
    • 2008
  • Intertidal benthic algal communities on the shores of Gujido and Daeyeonpyeongdo islets, Korea, were examined in October 2007. At both sites, 45 seaweeds including 7 green, 6 brown and 32 red algae were identified. The number of species at Gujido(38 species) was 1.5 times higher than at Daeyeonpyeongdo(25 species), but seaweed coverage was very similar with about 20%. Dominant seaweeds in terms of coverage and importance value were Hildenbrandtia sp., Caulacanthus okamurae, Ulva pertusa, and Gelidium amansii at Gujido and U. pertusa, Hildenbrandtia sp., Gelidium divaricatum at Daeyeonpyeongdo. The vertical distribution pattern of the seaweeds was G. divaricatum-U. pertusa, Hildenbrandtia sp.-U. pertusa, Hildenbrandtia sp., Ishige okamurae from upper to lower intertidal zone but seaweed zonations were not observed on the Gujido rocky shore. At both sites, coarsely-branched forms were the dominant functional group in species number and percent cover(among benthic algal species). The rocky shores of the two sites were dominated by crustose coralline and green algae, whose presence generally results in decreased seaweed biodiversity and community stability. Therefore, the shores of the Yeonpyeongdo islets are of considerable environmental concern and should be monitored for seaweed species composition and community structure.

New record of four ciliates(Protozoa, Ciliophora) collected from rocky intertidal pools of South Korea

  • Choi, Jung Min;Jung, Jae-Ho;Kang, Jung-Hoon;Kim, Young-Ok
    • Journal of Species Research
    • /
    • v.9 no.4
    • /
    • pp.455-461
    • /
    • 2020
  • Marine benthic ciliates were collected from four rocky intertidal pools along the eastern and southern coasts of Korea from 2012-2013. Ciliate specimens were examined by observing living and stained cells. Four ciliate species were new to Korea based on morphological characteristics as follows. (1) Aspidisca polypoda (Dujardin, 1841): small bean-shaped (ca. 30 ㎛), eight conspicuous dorsal ridge, polystyla-arrangement of frontoventral cirri; (2) Epiclintes auricularis auricularis (Claparède & Lachmann, 1858): tripartite and auriform body (ca. 300 ㎛), 46 adoral membranelles, one or two frontal and 23 transverse cirri, 12 oblique fronto-midventral rows; 59 left and 71 right marginal cirri; (3) Pseudochilodonopsis marina Song, 1991: reniform body (ca. 50 ㎛), two obliquely positioned contractile vacuoles, seven left and five right kineties, five fragmented preoral kineties; (4) Dysteria semilunaris (Gourret and Roeser, 1888): oval-shaped (ca. 30 ㎛), two longitudinally positioned contractile vacuoles, conspicuous longitudinal grooves on both plates, four or five right kineties, one short row below frontoventral kineties.

Astudy on the classification of Eastern Coastal line of korea from the view point of Prevailing Wave Direction (탁월파랑에 의한 동해안선 분류의 조사연구)

  • 이원환;이정태
    • Water for future
    • /
    • v.11 no.1
    • /
    • pp.39-46
    • /
    • 1978
  • The approaching deep water wave heights and directions affect the wave energy which is carried to the coast. By studing the relations between the longshore wave energy theory and the evolution of coastline, writer can arrive following conclusion. The longshore lottoral drifting affects to a great deal the formation of the coast, and by investigating on the eastern coastal geomophorogy of korea, the theory was proued as a true and made it possible to an approaching to the subdivided classification of eastern coast of lorea. That is to asy that angle taken by the level between the wave crest line of prevailing wave(NE) and the coastline was measured as less than 15#, and in the area neighboring the river which served as source of Sand parrticles, there are grand scale formation of sand beach expectable, in the other hand the formation of sand beach in case of $35^{\circ}{\leq}{\alpha }o{\leq}55^{\circ}$ which represents the vivid phenomena of longshore littoral drifting was proved not influencial but rather transformed into a rocky coast. Depending on the above facts the writer classified general shape of the coast affected by the vivid wave action into the following three, (1) The equilibrium beach. (2) Erosinal beach. (3) Geomophorogical beach, and made the sandy and rocky coast are subdivided as S-A.B.C. and R-DEF.

  • PDF

Stability Analysis of Embankment Slopes Consisting of Rock Fragments (암석 버력으로 성토한 사면의 안정성 해석)

  • 김치환
    • Tunnel and Underground Space
    • /
    • v.12 no.2
    • /
    • pp.83-91
    • /
    • 2002
  • Stability analysis of rocky embankment slopes is done by both the limit equilibrium method and the finite difference method. The height or the rocky embankment is approximately 40 m and the side slope is 1 vertical to 1.5 horizontal. The cohesion and internal friction angle of rock debris are assumed zero and 43$^{\circ}$, respectively. For finite difference analysis, strength reduction method is used to calculate the saft factor of the slope. As a result, the safety factor of the slope is discovered to be 1.4 by using either methods. Considering that the design criteria of the safety factor is 1.3, it can be judged that the rock fragments embankment slope is in a stable state.

Behavior of Lateral Resistance according to Embed Depth of Pile for the Wind Power Foundation Reinforced with Piles in the Rocky Layer (암반지반에서 말뚝으로 보강된 풍력발전 기초의 말뚝 근입깊이에 따른 수평저항력 거동)

  • Kang, Gichun;Kim, Dongju;Park, Jinuk;Euo, Hyunjun;Park, Hyejeong;Kim, Jiseong
    • Journal of the Korean Geosynthetics Society
    • /
    • v.21 no.2
    • /
    • pp.49-56
    • /
    • 2022
  • This study conducted to obtain the lateral resistance of a wind power foundation reinforced with piles through an model experiment. In particular, the lateral resistance of the foundation was compared with the existing gravity-type wind power foundation by integrating the pile, the wind power generator foundation, and the rocky ground. In addition, changes in the lateral resistance and bending moment of the pile were analyzed by embeded depths of the pile. As a result, it was found that the lateral resistance increased with the depth of embedment of the piles. In particular, the pile's resistance increase ratio was 2.11 times greater in the case where the pile embedded up to the rock layer than the case where the pile was embedded into the riprap. It was found that the location of the maximum bending moment occurred at the interface between the wind turbine foundation and the riprap layer when the pile embeded to the rock layer. Through this, as the lateral resistance of the wind power foundation reinforced with piles is greater than that of the existing gravity-type wind power foundation, it is understood that it can be a more advantageous construction method in terms of safety.