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博碩士論文 etd-0915106-122344 詳細資訊
Title page for etd-0915106-122344
論文名稱
Title
南海北部沉降顆粒及沉積物中鉛-210與質量通量之比較
Fluxes of Pb-210 and Mass:Comparisons Between the Settling Particulates and Sediments in the Northern South China Sea
系所名稱
Department
畢業學年期
Year, semester
語文別
Language
學位類別
Degree
頁數
Number of pages
64
研究生
Author
指導教授
Advisor
召集委員
Convenor
口試委員
Advisory Committee
口試日期
Date of Exam
2006-07-19
繳交日期
Date of Submission
2006-09-15
關鍵字
Keywords
沉降顆粒、沉積物、鉛-210
Pb-210, Settling Particulates, Sediments
統計
Statistics
本論文已被瀏覽 5667 次,被下載 1344
The thesis/dissertation has been browsed 5667 times, has been downloaded 1344 times.
中文摘要
本研究利用位於南海北部近岸地區及呂宋海峽西側之測站所取岩心,分析其Pb-210活度之垂直分佈,以估計沉積速率及質量累積率,並試圖與已量測之顆粒沉降通量作比較。又於呂宋海峽西側的測站進行水體中Po-210 及Pb-210在顆粒態與溶解態分佈的比較研究。研究樣本來自海研一號(ORI)688航次(2003年7月)在G、H二測站與722航次(2004年6及7月)在M1、F、1三測站,分別採取箱型岩心,以及763航次(2005年8月)在S7站採取剖面水樣。H、G、1三站位於南海北部陸棚近岸區,M1、F、S7三站則位於呂宋海峽西側之深水區。
海峽西側所取岩心F及M1的含水率大多在40%∼55%,而南海北部近岸地區岩心H、G、1的含水率約為25%∼37%。總有機物含量由燒失量估得,海峽西側之深水岩心F及M1平均分別為6%與12%,近岸地區岩心則約3%∼8%。各岩心樣本之Pb-210活度隨著深度而逐漸遞減成定值,表示已無超量Pb-210存在。利用超量Pb-210分佈所估得的沉積速率介於16~52 cm/100yr。於M1測站最深處(2848m)的沈積物收集器所得到的Pb-210通量和質量通量平均分別只有129 dpm/m2/d與0.55 g/m2/d(Chung et al., 2004),遠比由岩心估算的Pb-210通量(201 dpm/m2/d)與質量通量(5.3 g/m2/d)小:Pb-210通量只有岩心的65%,質量通量則只有10%,可能是因岩心沈積速率高估(受到生物擾動)及外來沈積物的側向輸入所造成。近岸地區岩心相對於海盆有較高的質量通量,但Pb-210通量卻較低,係因近岸地區水深很淺,可被清除的Pb-210較少,且未見邊界清除作用的影響。
S7測站的Pb-210比活度約介於115~900 dpm/g之間,Po-210則介於78~507 dpm/g之間。Po/Pb比值只有1800 m處約等於1,其他均小於1,顯示Po-210在顆粒態中並無富集而是不足的分佈。該站水體剖面的Po/Pb比值大致均小於1,呈現Po-210相對於Pb-210為不足的現象,Po-210可能被浮游生物及其他生物所吸收利用。水體中的Po/Pb平均比值約為0.6,其Po-210移除之對應滯留時間約0.83年。
Abstract
This study has analyzed Pb-210 activity in cores taken from northern coastal South China Sea (SCS) and the area west of the Luzon Strait (LS) in order to estimate the sedimentation rates and the mass accumulate rates which allow a direct comparison with measured settling particulate fluxes. Also, the particulate and dissolved Po-210 and Pb-210 distributions in a water column located to the west of the LS were measured and compared with earlier data. Core samples were collected at Stations G and H (box cores) during the ORI-688 cruise (July, 2003) and at M1, F and 1 (box cores) during the ORI-722 cruise (June and July, 2004). The water column samples were collected at S7 during the ORI-763 curise (August, 2005). Stations H, G and 1 are located in the continental shelf of the northern SCS; Stations, M1, F and S7 are located in the deep water area west of the LS.
The water content of the cores at F and M1 west of the LS is mostly around 40%~55%, while that of the cores at H, G and 1 in the coastal area of the northern SCS ranges about 25%~37%. The total organic matter as estimated from the total loss on ignition at F and M1 is, respectively, about 6% and 12% on the average. The coastal cores contain about 3%~8% total organic matter. The Pb-210 activity generally decreases with the core depth but reaches a constant at a certain depth, below which the excess Pb-210 vanishes in the core. Based on the excess Pb-210 distributions in the cores, the estimated sedimentation rates vary between 16 and 52cm/100yr. At M1 station, the mean Pb-210 flux and the mean mass flux are, respectively, 129 dpm/m2/d and 0.55 g/m2/d as determined from the deepest sediment trap(2848m) (Chung et al., 2004). These values are much smaller than what were estimated from the cores: the Pb-210 flux at 201 dpm/m2/d and the mass flux at 5.3 g/m2/d. The Pb-210 flux obtained from the trap is 65% of that measured from the core, and the mass flux from the trap is only 10% of that from the core. These large differences may arise from an over estimation of the sedimentation rate in the core (due to bioturbation) and near-bottom lateral transport of sediments from elsewhere. Compared to the basin west of the LS, the mass flux at the coastal area is much higher but the Pb-210 flux is much lower, probably due to the fact that shallow water has little amount of Pb-210 to be scavenged and no boundary scavenging effect has been observed.
The Pb-210 specific activity at S7 station ranges from 155 to 900 dpm/g; the Po-210 activity at this station ranges from 78 to 507dpm/g. The particulate Po/Pb ratio is about unity at 1800m depth, but the ratio at all other depths is less than unity, indicating that the Po-210 is deficient relative to Pb-210 in particles at this station. The total (dissolved + particulate) Po/Pb ratio in the water column is generally less than unity, showing Po-210 deficiency relative to Pb-210 probably due to absorption and/or adsorption of Po-210 by plankton and other organisms. The Po/Pb ratio for the water column averages about 0.6, corresponding to a mean residence time of 0.83yr for Po-210 removal.
目次 Table of Contents
目錄
頁碼
中文摘要....................................................................................................Ⅰ
英文摘要....................................................................................................Ⅲ
目錄................................................................................................... ........Ⅳ
圖目錄................................................................................................... ....Ⅷ
表目錄........................................................................................................Ⅸ

第ㄧ章 緒論..........................................................................................1
第二章 研究方法..................................................................................4
2-1 採樣.............................................................................................4
2-2 前處理.........................................................................................6
2-2-1 岩心部分............................................................................6
2-2-2 水樣部分............................................................................6
2-3 Po-210核種分析(α法)................................................................7
2-3-1 岩心部分............................................................................7
2-3-2 水樣部分............................................................................8
2-4 Pb-210核種分析(β法)................................................................9
2-5 Po-210活度計算方法...............................................................12
2-6 β計數儀之偵測效率................................................................13
2-7 Pb-210活度計算方法...............................................................16
2-7-1 α法偵測Pb-210活度.......................................................16
2-7-2 β法偵測Pb-210活度........................................................16
2-8 不同偵測方法(α及β)之比較...................................................17
第三章 結果與討論…........................................................................20
3-1 研究測站之岩心………...........................................................20
3-2 含水率及有機質的變化...........................................................20
3-3 岩心Pb-210之活度分佈..........................................................30
3-4 Pb-210活度分佈與沉積速率...................................................34
3-5 Pb-210之存量(inventory)和通量(flux)....................................38
3-6 水樣之Po-210及Pb-210分析.................................................42
3-6-1 水文資料..........................................................................42
3-6-2 懸浮顆粒(SPM)分佈與Pb-210及Po-210之比活度.....42
3-6-3 Pb-210及Po-210分佈......................................................45
第四章 結論........................................................................................49

參考文獻....................................................................................................51






圖目錄
頁碼
圖1、Pb-210與Po-210在海洋中源、匯及傳輸示意圖...............................3
圖2-1、研究區域海底地形及測站位置.......................................................4
圖2-2、樣本(岩心及水樣)之Po-210與Pb-210活度分析流程.................11
圖2-3、Pb-210射源因硫酸鉛自我吸收效應而下降之效率校正曲線....15
圖3-1、岩心F及M1之含水率分佈剖面...................................................26
圖3-2、岩心1、G及H之含水率分佈剖面.................................................27
圖3-3岩心F及M1之燒失量(L.O.I.)分佈剖面........................................28
圖3-4岩心1、G及H之燒失量(L.O.I.)……..............................................29
圖3-5、岩心F及M1之Pb-210活度分佈剖面..........................................32
圖3-6、岩心1、G及H之Pb-210活度分佈剖面........................................33
圖3-7、岩心M1之超量Pb-210的自然對數分佈….................................36
圖3-8、岩心G之超量Pb-210的自然對數分佈........................................37
圖3-9、OR1-763(2005年8月)航次S7站及OR1-734(2004年10月)航
次F站之溫鹽圖.............................................................................43
圖3-10、S7站及F站之Pb-210及Po-210活度垂直剖面圖.....................48
表目錄
頁碼
表2-1、採樣航次各測站之採樣日期、位置及底深等資料......................5
表2-2、β計數儀偵測實驗結果................................................................15
表2-3、岩心樣本之Pb-210活度於α法與β法偵測結果之比較............18
表3-1、各岩心之含水率、L.O.I.及Pb-210活度分析結果……………..21
表3-2、簡單模式計算所得之沉積速率、超量Pb-210存量及通量比較.40
表3-3、M1測站岩心與沉積物收集器之質量通量及Pb-210通量........41
表3-4、ORI-763航次測站S7及OR1-734航次測站F之懸浮顆粒濃度及Pb與Po比活度...................................................................44
表3-5、S7測站之Pb-210及Po-210活度................................................47
參考文獻 References
參考文獻
中文部份
林育農,1991,台灣東部及東北部黑潮海域釙-210與鉛-210之放射性地球化學,國立中山大學海洋地質及化學研究所碩士論文,98頁。
張婉琪,1993,台灣東北海域沉積物鈾釷系列核種之地球化學,國立
中山大學海洋地質研究所碩士論文,43頁。
張慧貞,2002,南海北部海域及高屏峽谷之沈降顆粒及沈積物:通量、粒徑與鉛、釙不平衡,國立中山大學海洋地質及化學研究所碩士論文,51頁。
蔡守文,1989,台灣海峽沈積物鉛-210定年法之應用,國立中山大學海洋地質及化學研究所碩士論文,51頁。
蘇育田,2005,呂宋海峽與南海北部水體中210Pb與210Po之活性不
平衡,國立中山大學海洋地質及化學研究所碩士論文,27、36
頁。




英文部份
Anderson, R. F. and S. L. Schiff, 1987. Determining sediment accumulation and mixing rates using 210Pb, 137Cs, and other tracers:
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Lin, Y. N. and Y. Chung, 1991. Pb-210 and Po-210 distributions and their radioactive disequilibria in the Kurshio Waters off eastern and northeastern Taiwan. Terrestrial, Atmospheric and Oceanic Sciences (TAO), 2, 243-265.
Tsai, S. W. and Y. Chung, 1989. Pb-210 in the sediments of Taiwan Strait. Acta Oceanogr. Taiwan., 22, 1-13.
Wyrtki, K., 1961. Physical Oceanography of the Southeast Asian Waters, NAGA Report, 2, Scripps Institution of Oceanography, La Jolla, California, 195pp.
Yang, H. S., Y. Nozaki, H. Sakai, Y. Nagaya and K. Nakamura, 1986.
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