Geomorphology of the Australian margin and adjacent seafloor
Geomorphology of the Australian margin and adjacent seafloor
复制标题
DOI：
10.1080/08120090801888669
复制
发表时间：
2008-05
影响因子：
1.2
通讯作者：
A. Heap;Peter T. Harris
中科院分区：
文献类型：
--
作者：
A. Heap;Peter T. Harris
首次系统地绘制了澳大利亚大陆边缘大部分地区和邻近海底的海底地貌特征分布图。21个地物类型中的每一个都是使用新的250米空间分辨率测深模型和辅助文献确定的。绘制的总面积超过890万平方公里，包括澳大利亚大陆周围的海底以及圣诞、科科斯（基林）、麦夸里和诺福克群岛等岛屿领土。在这一总测绘面积中，大陆架面积大于190万平方公里（21.92%），坡度大于400万平方公里（44.80%），深海平原/深海底面积大于280万平方公里（32.20%）。上升覆盖97 070平方公里或1.08%的地图面积。共绘制了6702个地貌特征。高原面积最大，为149万km 2，占16.54%，其次为盆地（71.4万km 2，占7.98%）和阶地（57.77万km 2，占6.44%），其余14种类型各占5%以下。珊瑚礁共有4172个个体特征（47900平方公里; 0.54%），是数量最多的地貌特征类型，主要是由于大堡礁的个体珊瑚礁数量众多。边缘的地貌是最复杂的边缘高原，阶地，沟/槽和海底峡谷存在。与全球海底地貌的比较表明，澳大利亚大陆边缘在大陆架和海隆区的代表性相对不足，而在斜坡区的代表性则相对较多，这种格局反映了大陆的三面为大陆-海洋边缘和相关的大型边缘高原所包围。值得注意的是，澳大利亚边缘的边缘高原占世界边缘高原总面积的20%。通过量化特征诊断组合的区域差异，可将绘制的区域划分为10个地貌区域，这些区域可用作推断大规模海底生境类型的起点。目前的研究应用于澳大利亚的海洋资源的未来管理。
For the first time, the distribution of seafloor geomorphic features has been systematically mapped over much of the Australian margin and adjacent seafloor. Each of 21 feature types was identified using a new, 250 m spatial resolution bathymetry model and supporting literature. The total area mapped was >8.9 million km2 and included the seafloor surrounding the Australian mainland and island territories of Christmas, Cocos (Keeling), Macquarie and Norfolk Islands. Of this total mapped area, the shelf is >1.9 million km2 (21.92%), the slope >4.0 million km2 (44.80%) and the abyssal plain/deep ocean floor >2.8 million km2 (32.20%). The rise covers 97 070 km2 or 1.08% of the mapped area. A total of 6702 individual geomorphic features were mapped. Plateaus have the largest surface area and cover 1.49 million km2 or 16.54%, followed by basins (714 000 km2; 7.98%), and terraces (577 700 km2; 6.44%), with the remaining 14 types each making up <5%. Reefs, which total 4172 individual features (47 900 km2; 0.54%), are the most numerous type of geomorphic feature, principally due to the large number of individual coral reefs of the Great Barrier Reef. The geomorphology of the margin is most complex where marginal plateaus, terraces, trench/troughs and submarine canyons are present. Comparison with global seafloor geomorphology indicates that the Australian margin is relatively under-represented in shelf and rise and over-represented in slope area, a pattern that reflects the mainland being bounded on three sides by rifted continent – ocean margins and associated large marginal plateaus. Significantly, marginal plateaus on the Australian margin cover 20% of the total world area of marginal plateaus. The mapped area can be divided into 10 geomorphic regions by quantifying regional differences in diagnostic assemblages of features, and these regions can be used as a starting-point to infer broad-scale seafloor habitat types. The present study has application for the future management of Australia's ocean resources.