해수중 화학원소의 거동과 생물활동

현상민,최영찬 제주대학교 해양과환경연구소 1997 해양과환경연구소 연구논문집 Vol.21 No.-

광 , 온도 및 GA침적처리가 한지형 잔디의 종자 발아에 미치는 영향

현상민,강훈,소인섭,김동일 한국잔디학회 1995 한국잔디학회 정기총회 및 학술발표회 Vol.8 No.-

A case study of a hard coral (Porites lutea) for Climate Change Research

현상민,박유현,박홍식 대한지질학회 2009 대한지질학회 학술대회 Vol.2009 No.

오끼나와 해곡 주장사료 퇴적물에 대한 저서생 유공충의 군집변화와 지역해 고환경변화

현상민,Hyun, Sang-Min 한국제4기학회 2009 제사기학회지 Vol.23 No.2

To investigate the paleoceanographic environmental changes around the Okinawa Trough, Japan, a piston core (RN88-PC5) was conducted on benthic foraminiferal species composition, assemblage, sedimentological and geochemical analyses. Trubidite sediment intercalated in studied core contains different benthic foraminiferal species, dwelling in shallow coral reef species, from normal hemipelagic sediment. These different benthic foraminiferal species and its assemblage are interpreted as reworked sediment when turbidite current occurred, synchronically. Grain size analysis clearly showed that mean grain size difference occurred between trubidite and hemipelagic sediments. Geochemical analysis also showed the difference of chemical composition between two sedimentary facies. Results of the foraminiferal oxygen isotope analysis showing global surface water warming records since the last 10 ka. The geochemcial analysis and previous works showed that turbidite sediment of studied core indicating sporadic occurrence of regional paleoceanographic events. Assemblage of shallow coral reef benthic foraminifera especially occurred with turbidite layer clearly support the sporadic occurrence of paleoceanographic events such as regional earthquake. 오끼나와 해곡 (Okinawa Trough)의 고해양 환경변화를 파악하기 위해 동 해역에서 얻어진 주상시료(RN88-PC5)를 이용하여 저서성 유공충의 종조성 및 군집구조를 파악하고 그 외 퇴적학적, 지화학적 연구를 수행하였다. 저탁류 퇴적물(turbidite sediment)을 협재한 주상시료는 같은 코아에서 나타나는 퇴적물인 반원양성 퇴적물 (hemipelagic sediment) 특성과는 다른 천해지역 산호초에 서식하는 저서성 유공충 종을 다량으로 함유하고 있다. 이들 천해역 저서성 유공충은 저탁류 퇴적물이 퇴적될 때 동시적으로 재동, 운반되어 퇴적된 것으로 해석되었다. 주상시료 퇴적물에 대한 입도분석 결과는 저탁류퇴적물과 반원양성 퇴적물과의 뚜렷한 입도변화를 보일 뿐만 아니라 두 퇴적물간에는 화학적 조성차이도 잘 보이고 있다. 부유성 유공충에 대한 산소동위원소 기록은 동 연구지역 표증해양이 홀로세에 들어서서 따뜻해지는 범 지구적인 기록을 공유하고 있는 것으로 나타났다. 또한 화학분석 결과와 기존의 연구결과를 종합하여 고찰하면 연구주상시료의 저탁류 퇴적물은 지역해의 고환경 기록인 저탁류 퇴적물의 주기적인 발생을 잠재적으로 지시하고 있는 것으로 해석된다. 연안 산호초지역에 서식하는 천해성 저서 유공충군집이 저탁류 퇴적층에 주기적으로 나타나는 것은 지역해에서 지진과 같은 고해양학적 사건이 주기적으로 일어났음을 지시한다.

Contents and Stable Isotopic Compositions of Organic Carbon and Total Nitrogen in the Surface Sediment of Two Coastal Bays in Korea

현상민,이태희,정섬규 한국해양과학기술원 2011 Ocean science journal Vol.46 No.4

Surface sediment from the coastal bays of Gwangyang and Masan in South Korea were analyzed for their contents and isotopic values of organic carbon and total nitrogen. The sources and diagenetic alteration of organic matter were also assessed. Total organic carbon varied from 0.22% to 3.48% (average = 1.40%, n = 75), and C/N ratios varied from 2.4 to 15.2 (average = 8.79, n = 75). δ^(13)C_(org) ranged from -19.92‰ to -25.86‰ (average = -21.21‰,n = 75), and δ^(15)N_(TN) ranged from 8.57‰ to 3.93‰ (average = 6.49‰, n = 75). Total organic carbon in both areas was associated with grain-size, with higher contents in finer grained sediment. The high carbon content observed in Masan Bay sediment correlated with its higher C/N ratio. δ^(13)C_(org) and δ^(15)N_(TN) varied widely, attributable to various influences such as the input of terrestrial organic matter and diagenetic alteration. The depleted δ^(13)C_(org)and higher δ^(15)N_(TN) observed in the sediment of Gwangyang Bay reflected terrestrial supply, implying that biogeochemical processes, i.e. bacterial degradation, were more active in Masan Bay sediment, which showed less depleted δ^(13)C_(org) and higher δ^(15)N_(TN) than Gwangyang Bay sediment. δ^(15)N_(TN) was the more useful indicator of biogeochemical processes in the highly anoxic sediment. These results indicate that the δ^(13)C_(org) and δ^(15)N_(TN) of sedimentary organic matter in coastal bays can indicate the source and degree of diagenetic alteration of sedimentary organic matter.

국제공동 해양 시추사업(IODP)의 등장과 지구과학에의 학술적 성과 및 한국프로그램(K-IODP)의 역할

현상민,장세원,이영주,Hyun, Sang-Min,Chang, Se-Won,Lee, Young-Joo 한국제4기학회 2011 제사기학회지 Vol.25 No.2

국제공동해양시추사업(Ocean Drilling Program: ODP)는 DSDP, IPOD 그리고 현재의 IODP 등의 여러 가지 이름으로 바뀌어 왔지만 공고한 국제협동을 통해 지구과학의 발전에 크게 기여하여 왔다. 약 10 년 전에 시작된 IODP는 이제 2013년부터 2단계로 진입하면서 더욱더 견고한 국제협력, 새로운 과학 영역에 대한 도전, 그리고 새로운 과학적 목표를 향해 발전해 나갈 것이다. 이 논문은 그동안 수행된 ODP탐사로 얻어진 탁월한 연구성과와 새롭게 출범되는 IODP의 구조와 새로운 과학영역을 한층 발전시키기 위해 필요한 역할에 대해 정리하였다. 특히 2단계로 접어드는 IODP에서는 현재까지 이루어지지 않았던 북극해와 같은 지역에 대한 조사와 심해 생물권(biosphere) 등 미생물 영역에 대한 연구, 기후변화에 대한 연구가 더욱 활성화 될 것으로 기대된다. 이처럼 IODP는 가맹국들의 강력한 국제협력을 통해 IODP는 앞으로도 지구과학의 발전에 중요한 역할을 할 것으로 생각된다. The ODP (Ocean Drilling Program) has been greatly contributed to the progress of Earth Science through the strong international cooperation with its name changed from DSDP DSDP(Deep Sea Drilling Program), IPOD (International Phase of Ocean Drilling) to IODP (Integrated Ocean Drilling Program). The IODP program which was launched about ten years ago will continue to develop toward the 2nd phase of scientific targets through the tight international cooperation. Distinguished scientific results from the various expedition as well as new phase of IODP structure and its important role that enhance the new scientific fields are summarized in this study. In particular, Arctic Expedition and deep-biosphere and high resolution climatic study that was not performed in previous ODP stages, will be extensively conducted in coming new 2nd IODP stages. Likewise, through strong international cooperation, it is expected that IODP would play an important role in Earth Science developments.

뇌실 외 배액술 시행 후 발생한 양측 청력저하 1예

현상민,강우석,정종우 대한이비인후과학회 2011 대한이비인후과학회지 두경부외과학 Vol.54 No.2

The sensorineural hearing loss following extraventricular drainage (EVD) is perhaps an underestimated complication rather than an uncommon event. Changes in the cerebrospinal fluid (CSF) pressure may lead to endolymphatic hydrops through the patent cochlear aqueduct resulting in sensorineural hearing loss. We describe the case of a 9-year-old child suffering from meduloblastoma. Bilateral hearing loss, especially at low frequency was found after emergent extraventricular drainage. At 2 months of treatment, hearing loss improved a little, but not restored to a serviceable hearing. Our experience and a review of articles indicate that early detection and awareness of hearing loss after EVD are important for treatment strategy.

마이크로네시아 축 경산호 골격의 지화학 원소 농도에 대한 예비연구

현상민,박흥식,김수현,김한준,장석,Hyun, Sang-Min,Park, Heung-Sik,Kim, Su-Hyun,Kim, Han-Jun,Jang, Suk 한국제4기학회 2008 제사기학회지 Vol.22 No.1

과거 수 년 간에 걸친 해양환경변화와 중금속 농도에 의한 오염정도를 알아보기 위해 열대 및 아열대 해역에서 흔히 볼 수 있는 경골산호(Porites lutea)를 조사하였다. 연X선 사진 분석 결과 분석된 산호시료는 길이 71mm 에 뚜렷한 성장륜을 가지고 있어 과거 수 년에 걸친 해양환경 변화를 잘 지시하고 있다. 골격 중에 포함된 주요원소 및 미량원소 분석결과 각 원소의 최고값, 최저값 사이의 편차가 큰 것으로 나타났다. 원소들 간의 관계를 살펴본 결과 일부원소는 화학적 분배계수에 의해 aragonite 격자에 기계적으로 치환되어 축적된 것으로 판단되며 일부원소는 이차적인 환경요인에 의해 축적된 것으로 판단된다. Sr/Ca, Mg/Ca에 근거한 환경변화는 수년전에 큰 변화가 있었던 것으로 판단되며 Mg/Ca의 경우 특정기간에 큰 폭으로 증가하는 경향을 보인다. 일부 중금속의 농도는 크게 수 십배의 농도 변화를 보이고 있으며 특히 Cu, Zn의 경우는 성장하는 동안 Mg/Ca와 같은 거동을 보이는 것으로 나타났다. 이러한 요인은 아마도 지역적 오염과 해양환경변화와 관련이 있는 것으로 해석된다. 추후 전처리 과정 등을 포함한 추가적인 연구를 필요로 한다. We investigated metal concentrations and oceanic environment changes that have occurred over the past several years by studying the hard coral Porites lutea, which inhabits tropical and subtropical areas. Soft X-radiographs clearly showed distinctive annual bands within 71 mm coral sample, which reflect changes in the oceanic environment over this period. There were large fluctuations in the major and minor element concentrations. Considering the physicochemical partition coefficient, some elements accumulated in the aragonite matrix in a mechanical manner, while others were affected by environmental factors. The concentrations of some heavy metals varied over a wide range, implying local environmental effects. The variation of Sr/Ca and Mg/Ca in coral skeleton clearly showed large-scale fluctuation over the specific intervals, implying environmental changes during this period. The concentrations of heavy metals also show high fluctuations, and roughly accord with Mg/Ca variation. In addition, Cu and Zn seem to show cyclicity-like peaks, coincide with Mg/Ca variation over the specific intervals. Such variation might be related to local pollution and oceanographic changes. More detailed investigation is necessary, including the pretreatment of coral skeleton sediment.

Multi-proxy Stratigraphy and Paleoceanographic Variations in Sediment from the Korea Plateau, East Sea (Japan Sea), Over the Last 500 kyr

현상민,김진경,강정원,김길영 한국해양과학기술원 2022 Ocean science journal Vol.57 No.3

High-resolution geochemical measurements were performed on core E09-08, which was taken from the top flat area of the Korea Plateau in the East Sea (Japan Sea). Based on analyses of sedimentary lamination, high-resolution oxygen isotopes, alkenone sea surface temperature (SST) variations, and comparison with previous results from the eastern part of the East Sea, a detailed multi-proxy-based stratigraphy was reconstructed. The results demonstrated that the core bottom dates approximately 500 kyr in the late marine isotope stage (MIS) 13, and provides high-resolution data on the paleoceanographic regime in the study area. Biogenic components of total organic carbon (TOC), carbon and nitrogen isotopes of organic matter (δ13Corg and δ15Norg), and alkenone concentrations indicate a paleoceanographic regime shift within the last 500 kyr. The excursion of proxies of δ18O, δ13Corg and δ15Norg and alkenone-based SST indicate two modes of oceanographic conditions: strong negative coupled mode (SNCM) during MIS 2, 10, and 12, and normal oceanographic decoupled mode (NODM) during other MIS. These two modes were interpreted as the terrestrial organic matter source domain and high-productivity oceanographic domain, respectively. The SNCM is characterized by relatively low δ13Corg and δ15Norg, and a high C/N ratio (> 12), whereas the NODM is characterized by relatively high δ13Corg and high δ15Norg, implying that larger amounts of terrestrial material were supplied during MIS 2, 10 and 12, with enhanced productivity during other MIS. The SNCM and NODM mode are also strongly associated with eustatic sea-level changes. The δ13Corg and δ15Norg values and alkenone-based SST excursions over glacial-interglacial periods were generally consistent with global-scale paleoclimate variation, as well as local paleoclimate. This study employed multi-proxy-based stratigraphy to demonstrate dramatic oceanographic variations since MIS 13, indicating that the local oceanographic setting was superimposed on global glacial-interglacial variations.

광, 온도 및 GA 침지처리가 한지형 잔디의 종자발아에 미치는 영향

현상민,강훈,소인섭,김동일,Hyeon, Sang-Min,Kang, Hoon,So, In-Sup,Kim, Dong-Il 한국잔디학회 1995 한국잔디학회지 Vol.9 No.3

This study is aimed to understand the effects of temperature, light and GA soaking treatment on the seed germination of perennial ryegrass 'Dandy', creeping hentgrass 'Penlinks', tall fescue 'Arid' and Kentucky hluegrass 'Nasaw'. These experiments are carried in vitro, and their results obtained are summarized as the followings ; The optimum temperature for seed germination of perennial ryegrass 'Dandy' was found to he ranged at 20~30$^{\circ}C$, and the optimum temperature for germination of creeping bentgrass 'Penlinks', tall fescue 'Arid' and kentucky bluegrass 'Nasaw' seeds was found to be ranged at 20~25$^{\circ}C$, whereas the germination percentage under the below or above temperature of this range decreased. The germination of perennial ryegrass 'Dandy' and tall fescue 'Arid' seeds showed no effect on light, and while the germination percentage of creeping hentgrass 'Penlinks' increased more highly under the dark condition than under the light condition. The germination percentage decreased according to the higher temperature. The germination of Kentucky bluegrass 'Nasaw' seeds increased more highly under the dark condition than under the light condition at 20~25$^{\circ}C$, whereas the germination percentage under the dark condition at 15$^{\circ}C$ and 30$^{\circ}C$ decreased. In case of GA soaking treatment of seeds, all the cool season turfgrasses tested showed their own promoting effects on seed germination. The early germination of tall fescue 'Arid' was good without the soaking times. Creeping bentgrass 'Penlinks' and perennial ryegrass 'Dandy' had re-spectively the highest germination percentage at 10min and 1hr soaking treatment, and the longer the soaking time, the lesser the germination percentage. Kentucky bluegrass 'Nasaw' obtained the best results at 24has soaking treatment, and the longer the soaking time, the better the ger-mination percentage.