Deglacial sea-level record from Tahiti corals and the timing of global meltwater discharge
Deglacial sea-level record from Tahiti corals and the timing of global meltwater discharge
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DOI：
10.1038/382241a0
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发表时间：
1996-07-18
期刊：
影响因子：
64.8
通讯作者：
Rougerie, F
中科院分区：
文献类型：
--
作者：
Bard, E;Hamelin, B;Rougerie, F
最后一次冰川消退的时间对于我们理解大冰盖的动态及其对地球表面的影响非常重要。此外，冰川冰盖的消失导致流入海洋的淡水流量急剧增加，这可能会扰乱海洋的温盐环流，从而影响全球气候（4-7）。海平面上升见证了大陆冰盖的融化，但只有两个这样的记录-来自巴巴多斯（8，9）和新几内亚（10，11）珊瑚-已经准确地确定了日期。但这些珊瑚覆盖在活跃的俯冲带上，那里的构造运动很大，而且往往不连续（特别是在新几内亚），因此，明显的海平面记录可能会受到复杂的构造成分的污染。在这里，我们从塔希提岛，这是远离板块边界（因此可能是相对稳定的构造）和远离大型前冰盖的位置珊瑚化石的日期。由此产生的记录表明，在13，800日历年sp之前不久，海平面有一次大的跳跃，这与巴巴多斯珊瑚记录中的融水脉冲1A相对应（8，9）。这一事件的时间更准确地限制在大溪地记录中，揭示了融水脉冲与一个短暂而强烈的气候冷却事件（12-15）相吻合，该事件发生在博林-阿勒罗德温暖期（12-16）开始之后，但在新仙女木冷事件之前约1,000年。
THE timing of the last deglaciation is important to our understanding of the dynamics of large ice sheets(1) and their effects on the Earth's surface(2,3). Moreover, the disappearance of the glacial ice sheets was responsible for dramatic increases in freshwater fluxes to the oceans, which probably disturbed the ocean's thermohaline circulation and, hence, global climate(4-7). Sea-level increases bear witness to the melting of continental ice sheets, but only two such records-from Barbados(8,9) and New Guinea(10,11) corals-have been accurately dated. But these corals overlie active subduction zones, where tectonic movements are large and often discontinuous (especially in New Guinea), so the apparent sea-level records may be contaminated by a complex tectonic component. Here we date fossil corals from Tahiti, which is far from plate boundaries (and thus Is likely to be tectonically relatively stable) and remote from the locations of large former ice sheets. The resulting record indicates a large sea-level jump shortly before 13,800 calendar years sp, which corresponds to meltwater pulse 1A in the Barbados coral records(8,9). The timing of this event is more accurately constrained in the Tahiti record, revealing that the meltwater pulse coincides with a short and intense climate cooling event(12-15) that followed the initiation of the Bolling-Allerod warm period(12-16), but preceded the Younger Dryas cold event by about 1,000 years.