• Title/Summary/Keyword: Islands

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Analysis of the relationship between volcanic eruption and surface deformation in volcanoes of the Alaskan Aleutian Islands using SAR interferometry

  • Lee, Seulki;Lee, Chang-Wook
    • Geosciences Journal
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    • v.22 no.6
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    • pp.1069-1080
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    • 2018
  • The Alaskan Aleutian Islands form one of the world's largest volcanic island chains. The islands are exposed to both direct and indirect damage from continuous volcanic eruptions. Surface deformation is mostly observed before volcanic eruption, but with some volcanoes, such as Ontake Volcano, deformations cannot be detected. In this study, we analyzed volcanic eruptions in the Alaskan Aleutian Islands, which is a region of frequent volcanic eruptions. Based on our results, we predicted the type of eruption that would occur on Baekdusan Volcano according to the presence or absence of surface deformation. For this purpose, 10 sites were selected from areas where recent volcanic activity had occurred in the Aleutian Islands. Additionally, Advanced Land Observing Satellite Phased Array-type L-band Synthetic Aperture Radar (ALOS-PALSAR) and European Remote Sensing (ERS)-1/2 satellite data were obtained from 10 experimental sites. Based on the radar satellite data, the volcanic surface deformations were identified, and the characteristics of the volcanic eruption were quantitatively calculated by determining the presence of surface deformation. The results of this study should facilitate the process of correlation between volcanic eruption and surface deformation.

Relationships between Geographical Conditions and Distribution Pattern of Plant Species on Uninhabited Islands in Korea (우리나라 無人島嶼의 地理的 還境과 植物의 分布 pattern 사이의 相關性 分析)

  • 정재민;홍경낙
    • The Korean Journal of Ecology
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    • v.25 no.5
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    • pp.341-348
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    • 2002
  • Correlations among the island area, distance to mainland, latitude, longitude, human impacts, diversity and composition of vascular plants were investigated by analyzing data on 261 islands(10.3% of total number of islands in Korea) selected from the annual reports for 'the natural evironment survey of the uninhabited islands in Korea' published by 'Ministry of Environment' during three years from 1999. The area of surveyed 261 islands ranged 1,100 to 961,000㎡(average of 75,000㎡), and the distance to mainland ranged 0.15 to 51.5km (average of 14.9km). Total number of plant species recorded in those islands was 1,109 species throughout 30 families, and mean mumber of plant species of each island was 98.7 species. Native species were 1,003 species (90.4%), and exotic species were 106 species(9.6%). The families with the largest number of species was the Compositae with 114 species, and followed in the order of Gramineae(90), Leguminosae(54), and Rosaceae(53). The result of multi-dimensional scaling analysis based on the plant species composition showed that 261 islands were distinctly divided into two groups, western sea group(131 islands) and southern sea group(130 islands). The islands of western sea group(average area of 93,000㎡) had greatly larger area than them of southern sea group(average area of 57,000㎡), but the average number of species (average species of 192) per island were less than in southern sea group (average species of 233). And, the partitioning into two groups was responsible for the species restricted to southern than to western sea group. Therefore, this results suggest that the distribution pattern and the composition of plant species could be also affected by the latitude of the island. When the species-area model was applied to total island and plant species, these results indicate that the island area was the most significant predictor of plant species diversity, and the distance to mainland and the human impacts were also shown to be significant predictors of plant species richness. But when applied to both groups of islands by the stepwise selection method, the result showed that islands of southern sea group were greatly affected by the factors such as human impacts, distance to mainland and longitude than western sea group. For the purpose of conservation of natural ecosystem on the uninhabited islands in Korea, we will also examine how the human impacts and the invasion of exotic plant species will disturb the native species diversity.

Uniform Ag Thin Film Growth on an Sb-terminated Si(111) Surface

  • Park, Kang-Ho;Ha, Jeong-Sook;Lee, El-Hang
    • ETRI Journal
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    • v.19 no.2
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    • pp.71-81
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    • 1997
  • We report on the room-temperature-growth of highly uniform and ultrathin Ag films on Sb-terminated Si(111) surfaces, as evidenced from a scanning tunneling microscopy (STM) study in an UHV system. With predeposition of one monolayer (ML) of Sb, uniform growth of Ag islands was observed at room temperature. The Sb layer suppresses the surface diffusion of Ag atoms on Si surface and increases the Ag island density, and then the increased island density is believed to cause coalescence of Ag islands before the beginning of multilayer growth in higher coverages, resulting in the growth of atomically flat and uniform islands on the Sb surfactant layer.

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Opisthobranchs (Molluscs: Gastropodal from Ullung and Dog-do Islarlds, Korea (울릉도 및 독도산 후새류(연체동물 문: 복족 강))

  • 최병래;이종락
    • The Korean Journal of Zoology
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    • v.37 no.3
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    • pp.352-376
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    • 1994
  • Fifteen species in 10 families of Opisthobranchia were collected from Ulung and Dog-do Islands, Korea. Eight species of them, Cadlina japonica Baba, Aldisa cooperi Robilliard & Baba, Dendrodoris denisoni (Angas), Tritonfu festive (Steams), Notobryon mardi Odhner, Hermissendo crussicornis (Eschscholtz), Sakuraeolis monesto (Bergh) and Protaeolidiella atru Baba were not recorded in Korean waters previously. In addtion to these 8 species, 5 species of Aplvsia purvufa Guilding in Miirch, Bethellino citrine (Riippell & Leuckart), Pfeurobronchoeo iaponica Thiele, Chromodoris tinctorio (Ri'spell & Leuckart), and Hypselodoris festive (A. Adams) are new to the fauna of Ullung and Dog-do Islands.

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Geographical Distribution and Soil Characteristics of Elaeagnus Plants in Korea (한국산 보리수나무속 식물의 분포 및 생육지 토양 특성)

  • You, Young-Han;Kim, Kyung-Bum;An, Chung-Sun;Kim, Joon-Ho;Song, Seung-Dal
    • The Korean Journal of Ecology
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    • v.17 no.2
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    • pp.159-170
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    • 1994
  • The geographical distribution and soil characteristics of Korean Elaeagnus plants were investigated by literatures, field survey and soil analysis. Deciduous E. umbellata was distributed throughout the Korean peninsula including western and southern islands. Distribution area of evergreen Elaeagnus plants was classified into three groups; E. macrophylla and E. glabra belonged to group l occurring in the southern, western and eastern islands; E. submacrophylla to group 2 occurring in the southern and western islands; E. maritima and E. ankaii to group 3 in the southern islands only. Deciduous E. umbellata appeared euryeciously from poor soil to rich one, whereas evergreen Elaegnus plants appeared stenoeciously in haline soil near coast.

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Spider Fauna in Quite and Galapagos Islands from Ecuador (키토와 갈라파고스 제도의 거미상)

  • 김주필
    • Korean Journal of Environmental Biology
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    • v.20 no.3
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    • pp.263-267
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    • 2002
  • The faunistic study on the spiders (Arachnida, Araneae) from Quito and Galapagos Islands was carried out from 1st to 18th Aug. 2000. During the survey period, 50 species of 48 genera belonging to 22 families (include 1 undetermined species) were identified from 562 collecting individuals. The dominant family was Araneidae (Gasteracantha cancriformis : 32% of total species). The species of settling spiders were richer than those of hunting spiders among the identified spiders. The author redescribes and figures in detail Gasteracantha cancriformis, which was collected during a field trip of Quito and Galapagos Islands.

Revised Geology of the Deokjeok and Soya Islands in the Central-western Korean Peninsula

  • Park, Jeong-Yeong;Park, Seung-Ik
    • Economic and Environmental Geology
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    • v.53 no.5
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    • pp.631-643
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    • 2020
  • The central-western Korean Peninsula contains records of an Early Mesozoic collisional event related to the final amalgamation of the East Asian continent. Here, we present a renewed geologic map of the Deokjeok and Soya islands in the central-western Korean Peninsula and its explanatory note. Our geologic map was based on a detailed investigation of the northeastern area of both islands, which is characterized by a complex fault and shear zone system that accommodated the crustal deformation related to the Mesozoic post-collisional orogenic collapse and the subsequent structural inversion. We suggest future directions of study aiming at addressing issues regarding the deformational responses of crust to the Mesozoic tectonic transition and orogenic cycles.

The Study on Medicinal Flora of Several Uninhabited Islands in Jindo-gun, Chonnam province

  • Yang, Hyo-Sik;Kim, Jong-Wook;Oh, Man-Ho
    • Plant Resources
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    • v.6 no.1
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    • pp.36-52
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    • 2003
  • The medicinal plants in 22 unhabited islands of Jindo-gun, Chonnam provincde were investigated from March 2000 to October 2002. The medicinal plants in 22 uninhabited islands of Jindo-gun were consisted 366 taxa; 95 families, 269 genus, 309 species, 52 varieties, 3 forma, and 2 subspecies. Important medicinal plants on survey area were Lemmaphyllum microphyllum, Dendropanax morbifera, Ficus erecta, Farfugium japonicum, Machilus thunbergii, Juniperus chinensis var. procumbens, Dendrobium moniliforme, Pyrrhosia tricuspis, Cinnamomum japonicum, Pittosporum tobira, Kadsura japonica, and Daphniphyllum macropodum, This result can be used as basic information data for medicinal research and the conservation of uninhabited islands.

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Angiospermic Plant Diversity of Southeast Offshore Islands in Bangladesh

  • Sajib, Noor Hassan;Pasha, Mostafa Kamal;Uddin, Shaikh Bokhtear
    • Journal of Forest and Environmental Science
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    • v.32 no.1
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    • pp.27-38
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    • 2016
  • A total of 680 angiosperm plant species under 433 genera of 115 families have been recorded from the Southeast offshore Islands of Bangladesh including Nijhum Dwip, Hatiya, Sandwip, Kutubdia, Maheshkhali, Sonadia and Saint Martin's. Magnoliopsida is represented by 92 families, 344 genera and 546 species, whereas Liliopsida is represented by 23 families, 89 genera and 134 species. Habit analysis shows that herbs, shrubs, trees and climbers were represented by 331, 117, 169 and 63 species respectively. The plant diversity of the southeast offshore islands is under great risk because of many threats including natural and manmade. The aims of the present study are investigation, accumulation and documentation of the angiosperm plants of the area.

Impacts to the Micronesian islands by environmental change of globalization and climate change

  • Nagashima, Shunsuke
    • Journal of Ecology and Environment
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    • v.33 no.2
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    • pp.79-94
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    • 2010
  • This article focused on the environmental changes on atolls in Micronesia. First, we considered the problem. Second, we designed research that focused on the impacts of environmental changes especially in relation to globalization and global warming in the Federated States of Micronesia (FSM). The results were in accordance to the hypotheses that globalization had impacted prominently in communities on main islands and impact was lessened with increased distance from the centre. The fact that the islands are remotely situated and thus, in theory, do not have much outside influence, has not alleviated them from having societal concerns. The earth's environmental change is causing an impact on the main islands as well. This has been governed by distinctive characteristics in their geographical, regional, and contents. Moreover, they showed stronger concerns about impacts on the environment than globalization. A set of questionnaires was used as the principal assessment method to quantify the concerns relating to the environmental changes.