国际大洋钻探全球海平面变化研究进展

Research progress in global sea level change:A critical review on international ocean drilling

国际科学大洋钻探计划对全球海平面变化问题的关注始于1980年代初,至今已在被动大陆边缘、孤立碳酸盐台地、混积台地边缘、平顶海山等不同类型海区执行了23个与海平面变化相关的专题航次,采集了大量的钻探资料,为全球海平面变化研究提供了关键信息。依据这些资料,重建了近100 Ma以来的全球海平面变化历史,检验了Exxon的层序地层模型和海平面假说,明确了海平面变化的地层响应,建立了南极冰盖演化与海平面变化的关系。尽管如此,科学大洋钻探海平面变化研究仍存在一些不足,如钻探区的地域代表性还不够多,全球海平面变化信息提取时难以消除其他地质因素(如构造沉降)的影响,海平面变化记录的精度有待提高,多种因素作用下地层结构对海平面变化的响应还需进一步研究,海平面变化机制特别是冰盖动力学对海平面变化的影响及暖期海平面变化的原因还认识不清。在当今气候变暖的大背景下,这些问题的解决有助于提升未来海平面变化趋势预测的可靠性。

The international scientific ocean drilling programs(DSDP,ODP,IODP)began focusing on global sea level changes in the early 1980 s.So far,23 related expeditions have been implemented in areas including passive continental margins,isolated carbonate platforms,mixed platform margins and guyots.As a result,a large number of drilling data have been collected to provide key research data.Based on these data,many achievements have been made,including the reconstruction of the history of global sea level changes during the past 100 Ma.In addition,the sea level hypothesis presented by scientists from EXXON was tested,the stratigraphic response to sea level change was clarified,and the relationship between the evolution of the Antarctic ice sheet and sea level changes was established.Nevertheless,research deficiencies still exist,such as inadequate representation of drilling areas,entanglement of sea level information with local geological effects(e.g.,tectonic subsidence),inaccurate sea level change recording,and a lack of understandings of the stratigraphic responses to and mechanisms of sea level changes(especially the influence of ice sheet dynamics and the cause of sea level changes in warm period).Under the background of today’s climate warming,resolving these issues will help making sea level change predictions more reliable.