【摘要】 <正>在地球历史上,发生过气候的多次剧烈变动,仅在第四纪二百多万年的历史中就曾发生过二十余次冰期。每个冰期旋回约十万年,其中还包括众多时间较短、幅度较小的气候波动。同样,在地球历史上,海面也不是固定不变的,它也曾经历过多次的升降运动。引致海面升降的原因十分复杂,主要的原因有气候变化以及构造运动和大地水准面的变化。更多还原

【Abstract】 The present paper discusses climatic changes and sea-level fluctuations over past 20 000 years (especially Late and Post Glacial events) in East China.1. Based on studies of more than 450 prehistoric sites and more than 400 drill cores, the present paper identifies that, during past 18 000 years, there have been 10 intervals of sea-level oscillations.The time of sea-level fluctuations has been correlated with the climatic variations of China.2. Abrupt climatic variations were accompanied by rapid sea-level fluctuations during the Late Glacial.Evidences furnished by sporo-pollen analysis of the Late Pleistocene and Holocene deposits of the coastal plain of East China indicate that three cold periods interrupted by two warm intervals obviously occurred during the Late Glacial. The temperature range between the cold period and the adjacent warm interval reached 6?C. Studies based on the paleoclimatic indicators and rate of deposition strongly suggest that the time interval during which the warm Auer d dropped into the cold Younger Dryas lasted less than 200 years.From 13 150 B. P. to 12 400 B. P. the sea level jumped from ?3 to ?5 m with the highest rising rate of 64 mm/year. It was the most rapid phase of sea-level rising experienced during the last 15,000 years. On the contrary, at 11 050 B. P.-10 900 B. P. occurred the most rapid phase of sea-level lowering which displayed a remarkable interruption of the tendency sea-level movement during the Late Glacial. As revealed from drill cores in eastern China the sea level dropped abruptly from -26m to ?3m within 150 years at the beginning of Younger Dryas.3. It is noticeable that the synchronous relation between climatic and sea-level fluctuations not only existed with the time scale for 103 years but also for 101-102 years. The climatic and sea-level curves of China from 1890?940 coincide each other very nicely. During the "warm epoch of twentieth century" mean temperature of 1935?940 was 1C higher than the 80’s of nineteenth century and consequently the sea level during 1935?1940 as recorded by the tidal gauge of Wu-song, near Shanghai, was 20 cm higher than that of 1910?920.4. The present paper tries also to predict the future trend of the sea level changes. More recent temperature data indicate that since the 1940s there has been global or at least North Hemispheric cooling.But in spite of the lowering of the mean temperature, the sea level has been rising steadily over the last four decades.The discordance means that as fossil fuel usage has increased rapidly, mankind might have disturbed the natural trend of the global temperature and the sea-level changes.更多还原