Coarse-Clast Ridge Complexes of the Caribbean: A Preliminary Basis for Distinguishing Tsunami and Storm-Wave Origins
Coarse-Clast Ridge Complexes of the Caribbean: A Preliminary Basis for Distinguishing Tsunami and Storm-Wave Origins
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加勒比海粗碎屑海脊复合体：区分海啸和风暴波起源的初步基础
DOI：
10.2110/jsr.2008.068
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发表时间：
2008
影响因子：
2
通讯作者：
G. Gelfenbaum
中科院分区：
文献类型：
--
作者：
R. Morton;B. Richmond;B. Jaffe;G. Gelfenbaum
摘要 加勒比海岛屿上沉积的沿海砾石-山脊复合体记录了过去可能与海啸或飓风有关的极端波浪事件。博内尔岛、牙买加、波多黎各（莫纳岛）和瓜德罗普岛的山脊复合体由大小不等的多峰碎屑组成，从沙子到粗石，这些碎石源自邻近的珊瑚礁或下面的岩石平台。山脊复合体的形态和波峰高程很大程度上取决于沉积物的可用性、碎屑的大小和波浪上升的高度。山脊复合体内部组织良好，显示出纹理排序和包括历史事件在内的广泛年代。有些呈现向海倾斜的河床和山脊和洼地地形，有些终止于扇形或陡峭的雪崩斜坡。形态学、沉积学、岩石地层学和年代地层学证据共同表明，由数十米宽、几米厚的砾石和沙子组成的与海岸平行的山脊复合体主要是风暴构造的特征，是由于多次高频强波事件而积累了几个世纪或几千年的结果。正如最近报道的那样，它们并不完全是一次或几次海啸的结果。海啸沉积可能是造成一些侧向山脊复合体增生或巨石场以及与山脊复合体相关的孤立块体的原因。
Abstract Coastal gravel-ridge complexes deposited on islands in the Caribbean Sea are recorders of past extreme-wave events that could be associated with either tsunamis or hurricanes. The ridge complexes of Bonaire, Jamaica, Puerto Rico (Isla de Mona), and Guadeloupe consist of polymodal clasts ranging in size from sand to coarse boulders that are derived from the adjacent coral reefs or subjacent rock platforms. Ridge-complex morphologies and crest elevations are largely controlled by availability of sediments, clast sizes, and heights of wave runup. The ridge complexes are internally organized, display textural sorting and a broad range of ages including historical events. Some display seaward-dipping beds and ridge-and-swale topography, and some terminate in fans or steep avalanche slopes. Together, the morphologic, sedimentologic, lithostratigraphic, and chronostratigraphic evidence indicates that shore-parallel ridge complexes composed of gravel and sand that are tens of meters wide and several meters thick are primarily storm-constructed features that have accumulated for a few centuries or millennia as a result of multiple high-frequency intense-wave events. They are not entirely the result of one or a few tsunamis as recently reported. Tsunami deposition may account for some of the lateral ridge-complex accretion or boulder fields and isolated blocks that are associated with the ridge complexes.