近2ka来东海内陆架泥质沉积物颜色反射率特征及其古气候意义

THE COLOR REFLECTANCE FEATURES OF THE SEDIMENTS IN MUD AREA ON THE INNER SHELF OF THE EAST CHINA SEA AND ITS PALEOCLIMATIC IMPLICATIONS FOR RECENT 2 ka

以东海内陆架泥质区MZ01孔岩心的颜色反射率测试分析为基础,通过一阶导数、因子分析等方法提取了对气候变化具有指示意义的替代性指标,结合AMS14 C年龄测试数据,建立了我国东部近2ka以来高分辨率气候演化的时间序列。该序列显示,900AD是我国东部2ka以来气候演化的关键转折点,900AD之后,气候明显变冷,冷暖波动频率高,但幅度较小。近2ka以来,我国东部的气候演化大致经历了冷期(580AD以前)、暖期(580—900AD)、冷暖波动期(900—1460AD)、冷期(1460—1880AD)4个阶段,每一阶段内部都存在次一级区域性或全球性的冷暖波动。

A climatic proxy system is constructed on the basis of the color reflectance data of the core MZ01 using first derivative and factors analysis method,and a high-resolution climatic sequence is established with the support of AMS14C dating data for the past 2 ka.900AD is the key turning-point in the course of climate evolution.Climate became significantly cold with high-frequency but low amplitude temperature fluctuation right after 900AD.In the past 2 ka,the climate in East China has experienced four stages including a cold stage before 580AD,a warm stage between 580 and 900AD,a temperature fluctuation stage between 900 and 1460AD and a cold stage between 1460 and 1880AD.Each stage includes some secondary regional or global temperature fluctuations.