English  |  正體中文  |  简体中文  |  Items with full text/Total items : 28611/40649
Visitors : 510699      Online Users : 56
RC Version 4.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
Scope Adv. Search

Please use this identifier to cite or link to this item: http://ntour.ntou.edu.tw:8080/ir/handle/987654321/32204

Title: Variations in monsoonal rainfall over the last 21 kyr inferred from sedimentary organic matter in Tung-Yuan Pond, southern Taiwan
Authors: Tien-Nan Yang;Teh-Quei Lee;Philip A. Meyers;Sheng-Rong Song;Shuh-Ji Kao;Ludvig Löwemark;Rou-Fei Chen;Huei-Fen Chen;Kuo-Yen Wei;Cheng-Wei Fan;Liang-Jian Shiau;Hong-Wei Chiang;Yue-Gau Chen;Min-Te Chen
Contributors: NTOU:Institute of Applied Geosciences
Keywords: Atomic TOC/TN ratio;East Asian summer monsoon;Holocene Thermal Optimum;Paleorainfall intensity;Taiwan;Younger Dryas
Date: 2011-11
Issue Date: 2012-06-15T07:40:55Z
Publisher: Quaternary Science Reviews
Abstract: abstract:Changes in paleorainfall intensity linked to the strength of the East Asian (EA) summer monsoon since 21 cal kyr BP are inferred from the organic matter contents of a 15-m sediment core from Tung-Yuan Pond in southern Taiwan. High total organic carbon/total nitrogen (TOC/TN) values in association with increased TOC content suggest that more soil-derived material containing terrestrial organic matter (OM) was delivered to the lake during periods of increased runoff associated with extensive precipitation that resulted from intensified summer monsoons, whereas low values indicate OM possessing a dominant algal origin during weakened summer monsoons. Rainfall intensity in terms of the proportion of terrestrial OM was high in four periods: the last deglaciation (∼17.2 to ∼12.2 ka), the early Holocene (∼10.6 to ∼8.6 ka), the middle Holocene Thermal Optimum (∼7.7 to ∼5 ka) and the late Holocene (∼4.2 to ∼2 ka), whereas it was low in the intervening time periods. High TOC/TN values coincide with peak values of summer insolation, and thus the strongest EA summer monsoon during the early and middle Holocene; small drops in these ratios correspond to increasing and decreasing solar radiation in the deglacial period and the late Holocene, respectively. The four intervals with low TOC/TN ratios, as well as episodic drops of the ratios during the deglaciation and the early and late Holocene are concordant with the late last glacial (∼21 to ∼17.2 ka), the Oldest (∼14.8 ka), the Older (∼13.3 ka) and the Younger Dryas (∼13 to ∼11.5 ka), the 8.2 cold event (∼8.6–7.7 ka) and a late Holocene cold event (∼5–4.2 ka), and suggest a weakened EA summer monsoon during these times. Moreover, high frequency hydrological variability occurred during the early Holocene, heavy rainfall persisted during the middle Holocene, and precipitation intensity generally diminished after ∼5 ka. The Tung-Yuan Pond sediment record indicates that the TOC/TN ratio can be used as a paleorainfall intensity proxy to trace variations in the EA summer monsoon strength in other small lakes.
Relation: 30(23-24), pp.3413–3422
URI: http://ntour.ntou.edu.tw/handle/987654321/32204
Appears in Collections:[應用地球科學研究所] 期刊論文

Files in This Item:

There are no files associated with this item.

All items in NTOUR are protected by copyright, with all rights reserved.


著作權政策宣告: 本網站之內容為國立臺灣海洋大學所收錄之機構典藏,無償提供學術研究與公眾教育等公益性使用,請合理使用本網站之內容,以尊重著作權人之權益。
網站維護: 海大圖資處 圖書系統組
DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - Feedback