Scavenging Phenomenon in the Taiwan Strait: 234Th/238U Disequilibria / 臺灣海峽表層水體清除作用探討:釷-234/鈾-238不平衡應用

碩士 / 國立臺灣大學 / 海洋研究所 / 95 / This study aims at the investigation of scavenging phenomenon by 234Th/238U disequilibria in the surface water of Taiwan Strait. Spatial sampling of 234Th was carried out by the Joint Hydrographic Survey during May 20~27, 2006. Along with 234Th measurement, basic hydrographic parameters (temperature, salinity, fluorescence and light transmission), total suspended matter concentration and particulate organic carbon concentration were also measured. The scavenging model incorporating the physical transport effect was used to estimate 234Th scavenging and removal rates in the region.
  According to the distributions of hydrographic parameters and 234Th, five major domains in the Taiwan Strait can be identified: (Ⅰ) the Southern Taiwan Strait; (Ⅱ) the Taiwan Bank; (Ⅲ) the Cho-shuei River mouth; (Ⅳ) the Middle Taiwan Strait; and (Ⅴ) the Ming River mouth. The 234Th scavenging rates ranged from 57 to 520 dpm/m3/d. The Cho-shuei River mouth showed the highest scavenging rate, and the lowest scavenging rate was found in the Taiwan Bank. The 234Th removal rates ranged from 24 to 381 dpm/m3/d. The highest removal rate appeared in the Cho-shuei River mouth, and the lowest removal rate was found in the Ming River mouth. The residence times of dissolved and particulate 234Th in the Taiwan Strait were short, 0~6 and 1~3 days, respectively. Using 234Th as a proxy of particulate organic carbon, average removal rates of particulate organic carbon in the Cho-shuei River mouth, the Middle Taiwan Strait, and the Ming River mouth were 7.2, 6.6, and 5.0 mmole/m3/d, respectively.

Identiferoai:union.ndltd.org:TW/095NTU05274022
Date January 2007
CreatorsYen-Ruei Hou, 侯雁睿
ContributorsChing-Ling Wei, 魏慶琳
Source SetsNational Digital Library of Theses and Dissertations in Taiwan
Languagezh-TW
Detected LanguageEnglish
Type學位論文 ; thesis
Format54

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