摘要
台风是当今人类社会面临的全球性重大环境灾害问题之一,但由于台风器测年限较短,限制了对台风长期演化机制的研究。沉积记录成为拓展台风记录时间跨度的重要载体,其中台风沉积的有效辨识是重要基础。尽管许多研究试图基于各种指标和方法来重建长时间尺度的台风活动,但目前仍缺少对台风沉积辨识指标与方法有效性的评估。本文以高分辨率的东海内陆架泥质区ZM02孔为载体,采用放射性同位素^(210)Pb和^(137)Cs定年法确定沉积物的年代序列。耦合器测记录和沉积记录,分析器测时期台风强度和频率与台风沉积敏感指标(如砂含量和D_(90))之间的对应关系,以期探讨台风沉积辨识指标和方法的有效性。结果显示,ZM02孔的平均沉积速率为0.97 cm/a,其上部4.5~100 cm的沉积年代为1917-2011年。砂含量和D_(90)均可作为东海内陆架泥质区台风沉积辨识的有效指标,阈值法的识别效果最好且稳定性高。砂含量可能是反映浙江海岸台风强度变化的潜在指标,而D_(90)则可能蕴含台风频率信息。这些认识有助于更准确地利用沉积记录去拓展台风记录的时间跨度,也有助于提高从沉积记录解译环境信息的能力。
Typhoons are one of the major global environmental disasters,and their variability is of great concern to modern society.However,the variability of typhoon activity and its climate drivers on centennial-millennial scales are less clear due to the lack of atmospheric instrumental records before the mid-19th century.Coastal sedimentary archives provide a means to extend our knowledge of typhoon dynamics,of which the effective identification of typhoon event layers is an important foundation.Although many studies have attempted to reconstruct typhoon activity on long time scales using various indicators and methods,there is still a lack of evaluation of the effective-ness of these indicators and methods for the identification of typhoon event layer.In this study,a high-resolution sedimentary record(Core ZM02)from the muddy belt of inner shelf of the East China Sea was used,and its dating framework was determined using ^(210)Pb and ^(137)Cs dating methods.The instrumental and sedimentary records were then coupled to analyze the correspondence between typhoon intensity and frequency and sensitivity indicators of typhoon deposits(i.e.,sand content and D_(90) in this study).The results show that the upper 4.5-100 cm of the core dates between 1917 and 2011 AD at a sedimentation rate of 0.97 cm/a.Among the three technical solutions,the threshold method was found to have the best identification and highest stability.Both sand content and D_(90) were found to be effective indicators for the identification of typhoon deposits in the study area.Sand content may be a potential indicator of typhoon intensity variation along the Zhejiang coast,and D_(90) contains information on typhoon frequency.The knowledge obtained here will not only contribute to the more accurate use of the sedimentary re-cord to extend the time span of the typhoon record,but also to improve the ability to decipher information from the sedimentary record.
作者
蔡瑞兮
张宇凡
张涛
杨阳
Cai Ruixi;Zhang Yufan;Zhang Tao;Yang Yang(School of Marine Science and Engineering,Nanjing Normal University,Nanjing 210023,China;Key Laboratory of Coastal Salt Marsh Ecosystems and Resources,Ministry of Natural Resources,Nanjing 210007,China)
出处
《海洋学报》
CAS
CSCD
北大核心
2023年第9期58-71,共14页
基金
自然资源部滨海盐沼湿地生态与资源重点实验室开放基金(KLCSMERMNR2021001)
国家自然科学基金(42276050)
南京师范大学交叉学科项目(164320H1847)。
关键词
台风频率
台风强度
沉积记录
器测记录
识别指标
东海内陆架
frequency of typhoons
intensity of typhoons
sedimentary records
instrumental records
indicators of identi-fication
inner shelf of the East China Sea
