Coastal evolution on volcanic oceanic islands: A complex interplay between volcanism, erosion, sedimentation, sea-level change and biogenic production
Coastal evolution on volcanic oceanic islands: A complex interplay between volcanism, erosion, sedimentation, sea-level change and biogenic production
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DOI：
10.1016/j.earscirev.2013.10.007
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发表时间：
2013-12
影响因子：
12.1
通讯作者：
R. Ramalho;R. Quartau;A. Trenhaile;N. Mitchell;C. Woodroffe;S. Ávila
中科院分区：
文献类型：
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作者：
R. Ramalho;R. Quartau;A. Trenhaile;N. Mitchell;C. Woodroffe;S. Ávila
海洋热点火山的增长和衰退与火山建设和侵蚀破坏之间的竞争有着内在的联系，海岸线处于这种对抗的前沿。在本文中，我们回顾了几种相互作用的机制，并有助于海洋岛屿火山海岸线的发展，以及这些过程如何在岛屿的整个生命周期中演变。火山建设过程中占主导地位的新兴岛屿和陆上盾牌建设阶段。在出现的岛屿阶段，苏尔采活动占主导地位，水碎屑和火山碎屑结构的形成，这些结构通常是短暂的，因为它们可以迅速消失的海洋侵蚀。随着陆上造盾阶段的开始，海岸演变的基本特征是通过熔岩三角洲的形成迅速但间歇性的横向增长，大大扩展了海岸线，直到它们通常达到最大程度。随着火山活动的后屏蔽静止，破坏性过程逐渐接管，海岸线后退，采用更突出的轮廓;质量浪费和海洋和河流侵蚀重塑景观，如果条件有利，生物过程发挥突出作用。侵蚀后的火山活动可能会通过恢复海岸线的扩张暂时扭转平衡，但岛屿不可避免地进入了一场长期的海平面生存战。珊瑚礁的生长和/或隆起也可能延长岛屿在海浪之上的寿命。然而，大多数岛屿的最终命运是由于海洋侵蚀造成的下沉和/或截断而被淹没。
The growth and decay of oceanic hotspot volcanoes are intrinsically related to a competition between volcanic construction and erosive destruction, and coastlines are at the forefront of such confrontation. In this paper, we review the several mechanisms that interact and contribute to the development of coastlines on oceanic island volcanoes, and how these processes evolve throughout the islands' lifetime. Volcanic constructional processes dominate during the emergent island and subaerial shield-building stages. During the emergent island stage, surtseyan activity prevails and hydroclastic and pyroclastic structures form; these structures are generally ephemeral because they can be rapidly obliterated by marine erosion. With the onset of the subaerial shield-building stage, coastal evolution is essentially characterized by rapid but intermittent lateral growth through the formation of lava deltas, largely expanding the coastlines until they, typically, reach their maximum extension. With the post-shield quiescence in volcanic activity, destructive processes gradually take over and coastlines retreat, adopting a more prominent profile; mass wasting and marine and fluvial erosion reshape the landscape and, if conditions are favorable, biogenic processes assume a prominent role. Post-erosional volcanic activity may temporarily reverse the balance by renewing coastline expansion, but islands inexorably enter in a long battle for survival above sea level. Reef growth and/or uplift may also prolong the island's lifetime above the waves. The ultimate fate of most islands, however, is to be drowned through subsidence and/or truncation by marine erosion.