Sedimentology of Coastal Deposits in the Seychelles Islands—Evidence of the Indian Ocean Tsunami 2004
Sedimentology of Coastal Deposits in the Seychelles Islands—Evidence of the Indian Ocean Tsunami 2004
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塞舌尔群岛沿海沉积物的沉积学——2004 年印度洋海啸的证据
DOI：
10.1007/s00024-014-0990-9
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发表时间：
2004
影响因子：
2
通讯作者：
Monthy
中科院分区：
文献类型：
--
作者：
Nentwig;Bahlburg;Monthy
塞舌尔群岛是印度洋上的一个群岛，距离苏门答腊岛西海岸4,500-5,000公里，受到2004年12月26日海啸的严重影响，波高高达4米。由于小岛屿的海啸历史往往由于年轻的历史记录而尚不清楚，因此研究其海岸保存的高能事件的地质痕迹非常重要。我们对2004年印度洋海啸对塞舌尔内岛的影响进行了调查。我们详细地研究了库里厄斯岛东海岸库里厄斯海洋国家公园老海龟池塘红树林中的岸上海啸沉积物。因此，它受到保护，不受人为干扰。在2004年海啸之前，它一直被一条500米长、1.5米高的堤道挡住，这条堤道建于1909年，是一个沉积物捕集器，确保了一个低能的水动力环境来保护红树林。这条堤道被2004年印度洋海啸摧毁。海啸导致红树林中沙叶的沉积，从而改变了栖息地。深色富含有机质的红树林土壤(1.9mΦ)被含有较粗的碳酸盐壳碎屑和碎屑的双峰细至中等碳酸盐砂层(1.7-2.2mΦ)所覆盖。潮间带沉积和红树林土壤是叶沉积的来源。海啸沉积的沙板被组织成不同的叶状物。根据岸上区域的形态，它们向陆地延伸到不同的淹没距离。距离海岸线180米的最大范围表明，距离海啸的最小淹没距离。沙叶的顶部覆盖了红树林的气团。砂丘沿线没有向陆地倾斜的趋势，矿床的正常分级很少，仅在7个地点中有1个发生。砂叶沉积也缺乏沉积构造。在沙丘表面，许多双壳类和软体动物的贝壳大多是碎裂的，分布在距海岸线150米的地方。完整的双壳类贝壳大多是凸面朝上的。在距海岸130-150米的花岗岩体的小岩架上，在海拔4米的不同海拔处沉积了大部分碎石大小的贝壳。这意味着海拔至少4米，从目前的海岸线上升到150米。
The Seychelles, an archipelago in the Indian Ocean at a distance of 4,500–5,000 km from the west coast of Sumatra, were severely affected by the December 26, 2004 tsunami with wave heights up to 4 m. Since the tsunami history of small islands often remains unclear due to a young historical record, it is important to study the geological traces of high energy events preserved along their coasts. We conducted a survey of the impact of the 2004 Indian Ocean tsunami on the inner Seychelles islands. In detail we studied onshore tsunami deposits in the mangrove forest at Old Turtle Pond in the Curieuse Marine National Park on the east coast of Curieuse Island. It is thus protected from anthropogenic interference. Towards the sea it was shielded until the tsunami in 2004 by a 500 m long and 1.5 m high causeway which was set up in 1909 as a sediment trap and assuring a low energetic hydrodynamic environment for the protection of the mangroves. The causeway was destroyed by the 2004 Indian Ocean Tsunami. The tsunami caused a change of habitat by the sedimentation of sand lobes in the mangrove forest. The dark organic rich mangrove soil (1.9 Φ) was covered by bimodal fine to medium carbonate sand (1.7–2.2 Φ) containing coarser carbonate shell fragments and debris. Intertidal sediments and the mangrove soil acted as sources of the lobe deposits. The sand sheet deposited by the tsunami is organized into different lobes. They extend landwards to different inundation distances as a function of the morphology of the onshore area. The maximum extent of 180 m from the shoreline indicates the minimum inundation distance to the tsunami. The top parts of the sand lobes cover the pneumatophores of the mangroves. There is no landward fining trend along the sand lobes and normal grading of the deposits is rare, occurring only in 1 of 7 sites. The sand lobe deposits also lack sedimentary structures. On the surface of the sand lobes numerous mostly fragmented shells of bivalves and molluscs were distributed up to 150 m from the coastline. Intact bivalve shells were mostly found positioned with the convex side upwards. On small ledges of a granitic body at 130–150 m from the shore mostly fragmented and gravel sized shells were deposited at different elevations up to 4 m above sea level. This implies a run up height of at least 4 m above sea level up to 150 m from the present shoreline.
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影响因子：
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作者：
M. Ortiz;R. Bilham
通讯作者：
R. Bilham
2004 年斯里兰卡海啸沙沉积物结构趋势的水动力影响
影响因子：
2.8
作者：
R. Morton;J. Goff;S. Nichol
通讯作者：
S. Nichol
塞舌尔群岛的古地磁和岩石学重建
影响因子：
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作者：
K. Suwa;K. Tokieda;M. Hoshino
通讯作者：
M. Hoshino
影响因子：
5.9
作者：
D. Stoddart;D. Cowx;C. Peet;J. Wilson
通讯作者：
J. Wilson
影响因子：
5.8
作者：
Kench, PS;McLean, RF;Aslam, M
通讯作者：
Aslam, M