Sizes, shapes, and patterns of coral reefs in the Maldives, Indian Ocean: the influence of wind, storms, and precipitation on a major tropical carbonate platform
Sizes, shapes, and patterns of coral reefs in the Maldives, Indian Ocean: the influence of wind, storms, and precipitation on a major tropical carbonate platform
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DOI：
10.1007/s13146-013-0176-z
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发表时间：
2014-04-01
影响因子：
1.4
通讯作者：
Schmitt, Dominik
中科院分区：
文献类型：
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作者：
Gischler, Eberhard;Storz, David;Schmitt, Dominik
马尔代夫是最大的珊瑚礁区之一。该群岛由21个环礁（14个较大的环礁和7个较小的环礁）和4个珊瑚礁环绕的岛屿（小环礁，泻湖完全由沉积物填充，即，已装满的水桶），总面积为21，370 km（2）。为了更好地了解这一主要碳酸盐岩台地位置的各种珊瑚礁形式，使用卫星图像和英国海军海图对珊瑚礁面积、珊瑚礁类型和其他地貌要素（例如通过边缘珊瑚礁、泻湖、泻湖斑块珊瑚礁和法罗群岛（在泻湖和边缘珊瑚礁中发现的较小圆形珊瑚礁）的通道）进行了量化。这些数字相互比较，并与降水，风应力，风速，电流强度和风暴影响等环境参数相关。地貌要素的大小和丰度表现出许多统计上显著的相关性。例如，珊瑚礁总面积与珊瑚礁和水道面积及丰度相关。较大环礁的泻湖深度从北向南增加，并与环礁面积和降水率相关，这可能是由于海平面低水位期间石灰石溶解以及较大的集水区可能产生较高的岩溶地貌。除了降水，风和风引起的波浪的影响似乎是非常重要的珊瑚礁类型在马尔代夫的空间格局。从南到北在群岛内，即，远离赤道，印度季风和风暴的影响变得更强。在同一方向上，泻湖礁和通过边缘礁的通道的丰度增加。法罗群岛的模式不那么清楚，法罗群岛是马尔代夫的典型，其形成模式一直存在争议。泻湖和边缘法罗群岛的数量在群岛的中北部达到最大值，并向北部和南部减少，原因尚不完全清楚。有人建议，法罗群岛形成通过过程中的横向沙运输在逆转季风和随后的殖民珊瑚。风应力似乎与法罗群岛的发展相关，因为它从南到北逐渐增加，在最北部又略有减少，就像法罗群岛的丰富程度一样。此外，飓风的破坏性影响最远只能到达马尔代夫的北方，可能不利于法罗群岛的发展。鉴于溶解在冰川海平面低水位也发挥了作用，在法罗群岛的发展，降水率下降（作为代理冰川石灰岩溶解）可能会阻碍法罗群岛的形成向北。
The Maldives are among the largest reef areas. The archipelago consists of 21 atolls (14 larger and 7 smaller ones) and 4 reef-fringed islands (small atolls with completely sediment-filled lagoons, i.e., filled buckets) that cover a total area of 21,370 km(2). In order to get a better understanding of the variety of reef forms in this major carbonate platform location, reef areas, reef types, and other geomorphological elements such as channels through marginal reefs, lagoons, lagoon patch reefs, and faroes (smaller circular reefs that are found in lagoons and at marginal reefs) were quantified using satellite images and British admiralty sea charts. These numbers were compared to each other and related to environmental parameters such as precipitation, wind stress, wind speed, current strength, and storm impact. Sizes and abundances of geomorphological elements show many statistically significant correlations. For example, total reef area covaries with reef and channel areas and abundances. Lagoon depth in larger atolls increases from north to south and correlates with atoll area and precipitation rates, probably as a result of limestone dissolution during sea-level lowstands and the fact that larger catchment areas may produce higher karst reliefs. Apart from precipitation, the influence of wind and wind-induced waves appears to be of great importance for spatial patterns of reef types in the Maldives. From south to north within the archipelago, i.e., away from the equator the influence of the Indian Monsoon and storms gets stronger. In the same direction, the abundance of lagoonal reefs and channels through marginal reefs increases. The pattern is not as clear for faroes, which are so typical for the Maldives, and whose mode of formation has been disputed. Both the numbers of lagoonal and marginal faroes reach maxima in the north-central part of the archipelago and decrease towards the north and south, for reasons not entirely clear. It is suggested that faroes form via processes of lateral sand transport during the reversing monsoon and subsequent colonization by corals. Wind stress appears to be correlated with faro development as it increases from south to north and slightly decreases again in the very north, just like the abundance of faroes. In addition, the destructive influence of cyclones, which only reaches as far south as the northern Maldives, might be detrimental to faro development. Given that dissolution during glacial sea-level lowstands also plays a role in faro development, the decreasing precipitation rates (as proxy for glacial limestone dissolution) might hamper faro formation towards the north of the archipelago.