• Title/Summary/Keyword: local uplift

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Marine Terrace of Daebo-Guryongpo-Gampo, SE Korea(II) (대보-구룡포-감포 지역의 해안단구(II))

  • 최성자
    • Economic and Environmental Geology
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    • v.37 no.2
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    • pp.245-253
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    • 2004
  • The 36km-long Daebo-Campo coast has a well-developed marine terraces divided to six steps by elevation of paleoshoreline : 0.5 m(T1), 10 m(T2), 30 m(T3), 40 m(T4), 60 m(T5) and 75 m(T6). The 2$^{nd}$ and 3$^{nd}$ platforms in Daebo to Guryongpo are wider and more distinctive than those of Guryongpo to Gampo. The 3$^{nd}$ terrace of 30 m high is subdivided to two flights as lower(T3b) and upper(T3a) by old sea cliff. Platform age is unclear because of coral fossil free. However, the terrace age could be determined with convergent OSL ages from beach sediments on 2$^{nd}$ step(T2). OSL ages of the terrace of 10 m high range in 60-70 ka. It reveals that the 2$^{nd}$ -step platform correlates to Oxygen Isotope Time scale, substage 5a(ca. 80 ka), and that uplift rate is ca. 0.19 m/ka for 2$^{nd}$ terrace at Daebo-Campo coast. If considering equivalent uplift rate for all terraces since the Late Pleistocene, the 3$^{rd}$ and 4$^{th}$ terraces would be 5e substage and 7 stage. The 30 m-high terrace provides a good indicator for uplift at Daebo-Gampo coast since 125,000 yrs(MIS 5e). It suggests that the local neotectonic deformation might cause an optional uplift rate of ca. 0.19 m/ka along the SE coast of Korea.

Local Seismic Activity around the Lützow-Holm Bay, East Antarctica

  • Kaminuma, Katsutada;Kanao, Masaki
    • Ocean and Polar Research
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    • v.26 no.3
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    • pp.523-529
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    • 2004
  • The seismic monitoring at Syowa Station$(69^{\circ}S,\;39^{\circ}E: SYO)$, located on the continental margin of the Eastern Dronning Maud Land, East Antarctica, began in 1959. Phase readings of the earthquakes have been reported since 1967 and have been annually published as part of the Data Report Series of the National Institute of Polar Research since 1968. An observation of a tripartite seismic network was carried out at SYO for a period of three years from 1987 to 1990. Epicenters of local earthquakes were determined for the first time by using the array network for the three-year period. Many different types of earthquakes, such as the mainshock-aftershock type, twin earthquake, earthquake swarms, etc., were detected during the period. After this, local events around SYO have been detected empirically from their waveforms recorded on seismograms. The seismic activity for the period of 1987-1990 was higher than that of the following decade. Earthquake epicenters, occurring during that period, were highly localized along the coast and in the central part of the $L\"{u}tzow-Holm$ Bay (LHB). Nine local earthquakes, recorded during the period of 1990-1996, showed many different types of events. The seismicity for the period of 1990-1996 was very low and the magnitudes ranged from 0.1 to 1.4. The locations of some events were determined by using the single station method for SYO, i.e., using the particle motions of the initial phase and S-P time. Two local events were detected in 1998 and one event in 2001. It would be estimated that the stress concentration was related to the glacial rebound around the LHB. Afterwards, we will be able to eventually examine the relationship between the seismicity around Antarctica and deglacial phenomena such as crustal uplift, and sea level change within the earth environmental system.

Incision Rate Distribution of Streams on the Northern Part of the Sobaek Mountain Range (소백산맥 북부 지역 하천의 하각률 분포)

  • Lee, Gwang-Ryul;Park, Chung-Sun
    • Journal of The Geomorphological Association of Korea
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    • v.27 no.3
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    • pp.41-51
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    • 2020
  • This study tried to reveal incision rate distribution of streams on the northern part of the Sobaek Mountain Range with OSL age dating and geomorphic analysis, and factors influencing on the distribution were also discussed. With results from the previous studies, a total of 10 sites from 7 streams in the study area showed the rates ranging from 0.220 m/ka to 0.297 m/ka. Namhan-gang and Geum-cheon indicated the highest and lowest rates, respectively. Both sides in the northern section in the study area showed similar rates, while the western side in the middle section and the eastern side in the southern section showed higher rates than the other sides. Higher rates were also found from the eastern and northern sides where the Range runs N-S and E-W directions, respectively. Certain relationships with altitude and distance from the divide can be recognized from the rates and may be attributed to active incision with altitude and location of the uplift axis near the present divide. The rates on granite and sedimentary rock were higher than those on metamorphic rock, indicating that bedrock type is one of the important factors influencing on stream incision. Tectonic movement seemed to play some roles in the rates, because areas with lineaments showed lower rates. This study suggests that incision rate distribution of streams on the northern part of the Sobaek Mountain Range reflects various local geomorphic and geologic conditions.

Holocene uplift rates in Korea (한반도의 현세 융기율)

  • Wook-Hyun Nahm;Hoil Lee;Chang-Pyo Jun
    • The Korean Journal of Quaternary Research
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    • v.32 no.1_2
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    • pp.41-50
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    • 2018
  • The most common method for estimating the uplifting rate is to measure the height of the coastal terraces. Coastal terraces are basically formed at the sea level position. During the Holocene age, both the height of the sea level and the coastal terrace are uncertain. The purpose of this paper is to clarify that the uplifting rate of the Korean Peninsula varies depending on the region, based on the height of sea level, the height of coastal terraces, and GPS observations. Gangwon-do and Jeolla-do provinces seem to have been stabilized at least since the beginning of the Holocene period. Overall distribution pattern of the uplifting rates on the Korean peninsula is likely to be related to the massifs. Of course, the boundaries of the massifs are faults, so the role of faults would be great. Essentially however, it is reasonable to consider that the difference in local uplift rates depends on the characteristics of the massif itself. The characteristics may include differences in response to stresses from tectonic movements, differences in crustal thicknesses, and so on.

Experimental Study on the Buckling Behavior of L-Shaped Header System (L-헤더 시스템의 좌굴 거동에 관한 실험 연구)

  • Park, Wan Soon;Kim, Gap Deuk
    • Journal of Korean Society of Steel Construction
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    • v.14 no.5 s.60
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    • pp.665-674
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    • 2002
  • The back-to-back and box-shaped headers used in light gauge steel structures have some disadvantages, i.e., construction efficiency and cost competitiveness. As such, cold-formed steel L-shaped headers have been developed and are used actively in advanced nations. However, this system has not been used in Korea because of inadequate investigation and adaptation efforts and lack of application example. Thus, this research evaluated the structural performance of L-header using buckling analyses and bending tests. Test results were compared using the AISI design criteria. Test results showed that local buckling and distortional buckling governed buckling behavior in gravity loads and uplift loads, respectively. These results were consistent with the calculated nomial strengths using the AISI design criteria.

Records of Holocene Environmental Changes in Terrestrial Sedimentary Deposits on King George Island, Antarctica; A Critical Review

  • Tatur A.;Valle R. Del;Barczuk A.;Martinez-Macchiavello J.
    • Ocean and Polar Research
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    • v.26 no.3
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    • pp.531-537
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    • 2004
  • In this study we discuss some problems that emerged from paleolimnological and paleontological investigations of terrestrial Holocene ecosystems on King George Island (South Shetland Islands) conducted by an Argentine-Polish research group. Biological and geochemical markers commonly used in standard analytical procedures are considered insufficient in tracing overlapping records of past environmental changes preserved in peat banks, lake sediments and ornithogenic remnants. Records that might be explained by predictable natural events (related to glacio-isostatic uplift of land), roughly predictable events (ecological succession), or unpredictable events (volcanic eruptions or accidental destruction of aquatic moss) may overlap or interfinger one with another providing that signals of regional and/or global climatic changes, are hardly identifiable. A more sophisticated and more selective methods are recommended to do discrimination between records of local and regional/golbal processes in studies on Holocene climatic history of the South Shetland Islands.

Development and the Application of Flood Disaster Risk Reduction Index (홍수피해저감지수(FDRRI) 개발 및 시범적용)

  • Moon, Seung-Rok;Yang, Seung-Man;Choi, Seon-Hwa
    • Journal of the Korean Society of Safety
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    • v.29 no.1
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    • pp.64-69
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    • 2014
  • Community-based disaster preparedness approaches are increasingly important elements of vulnerability reduction and disaster strategies. They are associated with a policy trend that values the knowledge and capacities of local people. In this research, we describe the community diagnosis method and develop Flood Disaster Risk Reduction Index(FDRRI) for assessment of flood vulnerability. FDRRI is composed of four indicators such as Flood Exposure Indicator(FEI), Sensitivity Indicator(SI), Risk Reduction Indicator(RRI), and Community Preparedness Indicator(CPI). We anticipate to present the guideline for selection national preparedness projects and uplift community's preparedness capacity.

Experimental Study on the Similitude of Small-Scale Models in Cyclic Lateral Behaviors of RC Shear Wall Subassemblages (RC벽식 부분구조의 반복 횡하중 거동에서의 축소모델 상사성 실험연구)

  • Lee, Han-Seon;Cho, Chang-Seok;Lee, Sang-Ho;Oh, Sang-Hoon;Park, Hong-Gun
    • Journal of the Korea Concrete Institute
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    • v.22 no.6
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    • pp.805-816
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    • 2010
  • For earthquake simulation test it is essential to make sure the similitude in behaviors between the full scale prototype and the reduced scale model. This paper presents the test results obtained through the cyclic lateral-force test, on two-story RC wall subassemblages. A lower 2-story portion of the prototype structure was selected as subassemblages. The global behavior such as the strength and ductility, and the local behavior such as flexural, shear and uplift deformation were measured. The test results of the 3 : 5 scale specimens representing the prototype were compared with those of 1 : 7 scale models. Two types of subassemblages were used: One with lintel beams and one without lintel beams. The comparison shows that 1 : 7 scale model simulated in general successfully the global and local behaviors of the prototype.

A Study on the Policy for Improving Treatment of Technical Manpower in Software Industry based on the Structure Analysis between Variables about Software Industry Policy (SW정책변수간 구조분석을 통한 SW기술인력 대우정책 연구)

  • Noh, Kyoo-Sung
    • Journal of Digital Convergence
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    • v.8 no.4
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    • pp.35-46
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    • 2010
  • Since the major requisite of software production is manpower, the core element of the competitive power of software is also manpower. However, economic treatments and social status of software manpower are in a very unsatisfactory situation. While Korean government has been continuing to drive the policy to foster the local software industry, the most cultivating policies of software industry are adjusted to the focus to create the local market in software field, reinforce the global competitive power, and intensify the competitive basis of small and medium size business organizations. So it is true that manpower which is key players and core elements of the software industry, have been shunned by the government policy. The purpose of this study is to initiate the necessity of the policy for technical manpower in the software industry and to suggest a policy program to uplift the treatment of them. To achieve this purpose, this paper will analyze the structural relation between variables about software policy and suggest policy programs to improve the treatment of manpower in the software field.

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Marine Terrace of the Jinha-Ilgwang Area, Southeast Korea (진하-일광 지역의 해안 단구)

  • 최성자
    • Economic and Environmental Geology
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    • v.36 no.3
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    • pp.233-242
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    • 2003
  • The southeasternmost coastal area of the Korean peninsula has been regarded as a seismologically stable area as neither Quaternary faults nor earthquake activity has been reported. To clarify whether the active tectonic movement has occurred or not, a digital marine terrace mapping and fracture mapping have been done in the coastal area. Bed rocks are composed of the Cretaceous volcanic and sedimentary rocks and the Paleogene granite. Wave-cut platform in the area is smaller and narrower relative to that of the northern coastal area. Most of the platforms in the area have little Quaternary sediment. The platforms except the Holocene terrace (1 st terrace) can be divided into three steps. The lowest platform (2nd terrace) has an altitude of 8-11 m. The broad middle one (3rd terrace) is 17 to 22 m high. The highest terrace (4th terrace) is a narrow and sporadic bench with an altitude of about 44 m high. The lowest terrace is correlated to the 2nd terrace of the northern area, which corresponds to the oxygen isotopic stage 5a. The uplift rate calculated from a graphic method is 0.19 m/ky. This low uplift is typical of an intra-plate, suggesting that the area is tectonically stable. The elevation of the platforms tends slightly lower from the north to the south in the survey area. The decreasing altitude of the platforms towards the south is interpreted to result from a local block tilting during the Latest Pleistocene. This also indicates that the eastern coast of the Korean peninsula has been suffering a subsidence to the south.