Termination of the Last Glacial Maximum sea-level lowstand: The Sunda-Shelf data revisited
Termination of the Last Glacial Maximum sea-level lowstand: The Sunda-Shelf data revisited
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DOI：
10.1016/j.gloplacha.2008.03.011
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发表时间：
2009-03-01
影响因子：
3.9
通讯作者：
Bojanowski, A.
中科院分区：
文献类型：
--
作者：
Hanebuth, T. J. J.;Stattegger, K.;Bojanowski, A.
末次冰期前后的海平面历史是最近有争议的辩论的焦点。然而，对这段时间内海平面变化的深刻理解是必不可少的，因为海平面是气候系统的一个中心参数，也是大陆边沉积的一个主要力量。在这里，我们提出了一个地震记录，以及来自巽他大陆架的增强数据[Hanebuth，T. J. J.，Stattegger，K.，齐藤，Y.，2002.由浅层地震勘测记录的巽他大陆架中部（东南亚）的结构。Geo-Marine Letters 22，86-94.]并将我们的结果与全球有效性的稀疏现有数据集，即波拿巴海湾记录[Yokoyama，Y.，兰贝克K.，德戴克P.，约翰斯顿河Fifield，L.K.，2000.根据观测到的海平面极小值确定末次盛冰期的时间。Nature 406，713-716.; Yokoyama，Y.，De Deckker，P.，Lambeck，K.，约翰斯顿，P.，Fifield，L.K.，2001.末次冰期最高峰的海平面：来自澳大利亚西北部的证据限制了氧同位素阶段2的冰量。Paleogeography Paleoclimatology Paleocecology 165，281-297.]，巴巴多斯珊瑚记录[费尔班克斯，R.G.，1989. 17，000年冰川-海平面变化记录：冰川融化日期对新仙女木事件和深海环流的影响。《自然》342，637-642。Peltier，W.R.，费尔班克斯，RG，2006.根据巴巴多斯海平面记录的全球冰川体积和末次冰期最大持续时间。Quaternary Science Reviews 25（23-24），3322-3337.]和大陆冰川消退的最新数值模型[Peltier，W.R.，费尔班克斯，RG，2006.根据巴巴多斯海平面记录的全球冰川体积和末次冰期最大持续时间。Quaternary Science Reviews 25（23-24），3322-3337.].海平面似乎在常规的末次冰期最高峰（LGM; 21-19 cal kyr BP）之前不久就已经较低。这个冰川低潮位周围的时间间隔并没有被巽他大陆架的年龄所覆盖，而是被一个古老的屏障-潮坪系统所记录。这些古海岸残留形式表明，这样一个早期的低点约5米深，比海平面是在末次盛冰期。巽他陆架末次冰期海平面重新计算为现代水深-123+/-2 m。该深度与巴巴多斯和波拿巴湾的低位数据非常吻合。最近假设的19 kyr海平面上升得到了Sunda和Bonaparte数据集的支持，尽管它可能早在19.6 cal kyr BP就已经开始，持续约800 kyr，幅度至少为10 m。这种早期的脉冲式上升可能发挥了至关重要的作用，在物理保存的高冰期早期冰消沉积物的巽他Shelf.The模拟海平面的历史，因此，支持相对于初始高冰期低水位之前的LGM，这可能是在明显的对比观察波拿巴。尽管如此，现场数据表明冰川海平面演变比模型深约10 m。此外，从模型中推导出的从26到16 cal kyr BP的逐渐上升趋势，不能被任何现场数据所证实。然而，我们的知识仍然是不令人满意的，从合适的地区扩大现场数据是迫切需要的。(C)2008 Elsevier B. V.保留所有权利。
The sea-level history around the last glaciation is in the focus of recent, controversial debates. A profound understanding of sea-level changes during this time interval is, however, essential since sea level is a central parameter in the climate system as well as a major force on continental margin sedimentation. Here, we present a seismic record together with augmented data from the Sunda Shelf [Hanebuth, T.J.J., Stattegger, K., Saito, Y., 2002. The architecture of the central Sunda Shelf (SE Asia) recorded by shallow-seismic surveying. Geo-Marine Letters 22, 86-94.] and compare our results in a careful evaluation with the sparse existing data sets of global validity, i.e. the Bonaparte Gulf record [Yokoyama, Y., Lambeck. K., DeDeckker. P., Johnston, R. Fifield, L.K., 2000. Timing of the Last Glacial Maximum from observed sea-level minima. Nature 406, 713-716.; Yokoyama, Y., De Deckker, P., Lambeck, K., Johnston, P., Fifield, L.K., 2001. Sea-level at the Last Glacial Maximum: evidence from nortwestern Australia to constrain ice volumes for oxygen isotope stage 2. Paleogeography Paleoclimatology Paleoecology 165, 281-297.], the Barbados coral record [Fairbanks, R.G., 1989. A 17,000-year glacio-eustatic sea level record: influence of glacial melting dates on the Younger Dryas event and deep ocean circulation. Nature 342, 637-642.; Peltier, W.R., Fairbanks, R.G., 2006. Global glacial ice volume and Last Glacial Maximum duration from an extended Barbados sea level record. Quaternary Science Reviews 25 (23-24), 3322-3337.] and the latest numerical model of continental deglaciation [Peltier, W.R., Fairbanks, R.G., 2006. Global glacial ice volume and Last Glacial Maximum duration from an extended Barbados sea level record. Quaternary Science Reviews 25 (23-24), 3322-3337.].Sea level seems to have been lower shortly prior to the conventional Last Glacial Maximum (LGM; 21-19 cal kyr BP). The time interval around this glacial lowstand is not covered by ages from the Sunda Shelf, but documented by an ancient barrier - tidal-flat system. These palaeo-coastal relict forms indicate such an early lowstand some 5 m deeper than sea level was during LGM times. The LGM sea level on the Sunda shelf is recalculated to -123+/-2 m modern water depth. This depth fits nicely with the lowstand data derived from Barbados and the Bonaparte Gulf. The recently assumed 19-kyr sea-level rise is supported by the Sunda and Bonaparte data sets combined, although it might have started already as early as at 19.6 cal kyr BP lasting for some 800 kyr with an amplitude of at least 10 m. This early pulse-like rise might have played a crucial role in the physical preservation of the high-glacial to early deglacial deposits on the Sunda Shelf.The modelled sea-level history is, thus, supported with respect to an initial high-glacial lowstand prior to the LGM, which might be in apparent contrast to observations from Bonaparte. Nevertheless, field data suggest a glacial sea-level evolution about 10 m deeper than the model. Also, the gradual rising trend from 26 to 16 cal kyr BP, as deduced from the model, can definitively not be approved by any field data. However, our knowledge is still unsatisfactory and an expansion of field data from suited areas is urgently needed. (C) 2008 Elsevier B.V. All rights reserved.